Help on Tele2, tariffs, questions

As a rule, lumber is used coniferous species.

For various elements and parts of the wooden rafter system, wood of a certain type and grade is used. When using lumber in a rafter-beam system, the following properties and indicators of wood must be taken into account: bending strength, compression, chipping, wood density and moisture content.

Wooden rafter structures must necessarily comply with the special degree of fire resistance of the room. They must be treated with special fire retardants and...

There is a huge variety of options and elements for constructing wooden rafter structures. Exist the following types rafter structures: layered or hanging rafters, combined, with ties, etc. The most popular rafter structures are layered and hanging.

To avoid sagging of the entire structure, a horizontal tie is attached to the lower end of the beam using strip steel clamps to support the beams of the entire attic floor. If the span is up to 12 m, then struts are introduced into the rafter structure, which reduce effective length everyone rafter legs.

Hanging wooden rafters work both in compression and bending.

Below we consider the types of rafter structures:

1. ordinary hanging rafters
2. double hanging rafters

It is not uncommon to increase the entire area of ​​the attic space in a wooden system hanging rafters Tightenings are not used, but struts are used.

Roof Mauerlat

In this case, the rafter legs are cut into the Mauerlat itself. The lower plane should lie on the wall, and in the upper one you need to make certain cuts for correct connection with rafter legs.

All struts rest against the end of the wooden one. In this case, the loads that would be compensated by the tightening are directly transferred to all walls. As a result, this solution for a wooden rafter system is only possible if there is a special massive construction.

Hanging rafters are parts and elements of rafter structures that are located in one vertical plane and are connected to each other using notches, bolts, nails, clamps and staples.

There is a combined rafter system - this is the installation of both a layered and a hanging rafter structure, which alternate in turns. Where there are no intermediate supports, hanging rafter systems are used, and where they are present, layered rafter systems are used.

Rafters with tie

Used for spans up to 15 m. Spans of this length require certain intermediate struts, i.e. in special puffs. They are mounted at the height of the building between two rafters and tied together. And longitudinal struts will prevent lateral bending.

Tightening the roof rafters

All structures with supporting wooden beams must be assembled in the form of rafter structures reinforced with special supports, which will rest on cross beams and all load-bearing walls, as well as in the form of truss systems. The concept of a truss is a structural element similar to an open triangular rod system, which is attached to the main truss load-bearing structures.

The structural rigidity of this roof is provided by a longitudinal strut or strut. The use of struts reduces the overall load on the entire structure. Vertical struts are usually attached to either racks using notches, trunnions, or steel plates.

Truss hanging timber trusses systems

Sprengel

The entire load from the rafter legs goes to the racks, which transmit it further to the load-bearing main ones. With this design, the load will be distributed between all load-bearing walls. The racks are mounted at the ends of the main load-bearing walls. The lower ends of all racks are secured using hanging pins.

Truss beams are made from solid solid wood or laminated boards. Usually they are small in height. Good and high-quality load-bearing capacity of truss beams is achieved using a truss system and wooden beams supporting it.

Shrengel beams can cover huge spans. Sometimes they are equipped with steel belts.

Complex rafter system designs

Available by type roof trusses. Lattice trusses are divided into types according to the shape of their openings: triangular, trapezoidal or parallel belts. Typically, lattice trusses are made symmetrical, but other options are possible, for example,. A common lattice truss includes top and bottom chords, posts and braces.

Reliable and high-quality connection of carriers wooden structures with central supports into one common system called a frame. The racks and beams connected into the frame are necessarily fastened or included in each other. Today there are two main types of frames - double-hinge and three-hinge. Double-hinged frames are equipped with a crossbar that runs across the entire width of the finished frame. These frames are best suited for structures with a small angle of inclination. Tri-hinged frames consist of two equal halves that support each other at the ridge of the roof. Three-hinge frames are used where a more significant angle of inclination is required.

Trust the calculations of rafter structures and the final selection of their elements and parts to specialists. Huge loads are applied. In addition to its own weight, it is affected by wind loads, heavy rains, hail, snow and ice. The roof quite often undergoes various

Roof installation is a complex multi-step process. To independently assemble and install a rafter system, you need to carefully study the methods of connecting elements, calculate the length of the rafters and the slope angle, and select the appropriate materials. If you don’t have the necessary experience, you shouldn’t take on complex designs. The best option for a residential building small sizes– do-it-yourself gable roof.

A standard roof of this type consists of the following elements:

Mauerlat is a timber laid on top of the walls along the perimeter of the building. It is secured using threaded steel rods embedded in the wall or anchor bolts. The timber must be made of coniferous wood and have a square section of 100x100 mm or 150x150 mm. The Mauerlat takes on the load from the rafters and transfers it to the external walls.

Rafter legs- these are long boards with a cross section of 50x150 mm or 100x150 mm. They are attached to each other at an angle and give the roof a triangular shape. The structure of their two rafter legs is called a truss. The number of trusses depends on the length of the house and the type roofing. The minimum distance between them is 60 cm, the maximum is 120 cm. When calculating the pitch of the rafter legs, you should take into account not only the weight of the covering, but also the wind load, as well as the amount of snow in winter.

It is located at the highest point of the roof and most often represents a longitudinal beam connecting both slopes. The beam is supported from below by vertical posts, and the ends of the rafters are attached to the sides. Sometimes the ridge consists of two boards that are nailed to the top of the rafters on both sides and connected at a certain angle.

Racks are vertical beams with a cross section of 100x100 mm, located inside each truss and used to transfer the load from the ridge run to the load-bearing walls inside the house.

The struts are made from scraps of timber and installed at an angle between the posts and rafters. Strengthened with struts side faces trusses, the load-bearing capacity of the structure increases.

Tie - a beam connecting the lower parts of the rafters, the base of the truss triangle. Together with the struts, such a beam serves to strengthen the truss and increase its resistance to loads.

A log is a long beam with a cross section of 100x100 mm, laid along the central load-bearing wall, on which the vertical posts rest. Lezhen is used when installing layered rafters when the run between the outer walls is more than 10 m.

The sheathing consists of boards or timber placed on the rafters. The sheathing can be continuous or with gaps, depending on the type of roof. It is always attached perpendicular to the direction of the rafters, most often horizontally.

If there is no more than 10 m between the external walls and there is no load-bearing wall in the middle, arrange hanging rafter system. With this system, the upper ends of adjacent rafters are sawn at an angle and connected to each other using nails, excluding the installation of racks and ridge beams. The lower ends of the rafter legs rest on the external walls. Due to the absence of racks, the attic space can be used for arranging an attic. Very often, the function of tightening is performed by floor beams. To strengthen the structure, it is recommended to install the top tie at a distance of 50 cm from the ridge.

If there is a central supporting wall, the arrangement is more justified layered rafter system. A bench is laid on the wall, support posts are attached to it, and a ridge beam is nailed to the posts. This installation method is quite economical and easier to implement. If ceilings in interior spaces are designed to different levels, the racks are replaced with a brick wall, dividing the attic into two halves.

The roof installation process includes several stages: attaching the Mauerlat to the walls, assembling the trusses, installing the rafters on the floors, installing the ridge, and attaching the sheathing. Before assembly, all wooden elements are carefully treated with any antiseptic composition and dried in air.

To work you will need:

• timber 100x10 mm and 150x150 mm;
• boards 50x150 mm;
• boards 30 mm thick for lathing;
• roofing felt;
• metal studs;
• jigsaw and hacksaw;
• hammer;
• nails and screws;
• square and building level.

IN wooden houses The functions of the mauerlat are performed by the logs of the last row, which significantly simplifies the work process. To install the rafters, it is enough to cut grooves of the appropriate size on the inside of the logs.

In brick houses or buildings made of blocks, installation of the Mauerlat occurs as follows:

The mauerlat bars must form a regular rectangle and be in the same horizontal plane. This will facilitate further installation of the roof and provide the structure with the necessary stability. Finally, markings are made on the beams for the rafters and grooves are cut along the thickness of the beam.

When choosing a hanging rafter system, it is necessary to assemble the trusses on the ground and then install them above the floors. First you need to draw up a drawing and calculate the length of the rafter legs and the angle of their connection. Typically, the roof slope is 35-40 degrees, but in open, heavily blown areas it is reduced to 15-20 degrees. To find out at what angle to connect the rafters, you should multiply the angle of the roof by 2.

Knowing the length of the run between external walls and the angle of connection of the rafters, you can calculate the length of the rafter legs. Most often it is 4-6 m, taking into account the eaves overhang 50-60 cm wide.

The upper ends of the rafters can be fastened in several ways: overlapping, end-to-end and “into the paw”, that is, with grooves cut out. Metal plates or bolts are used for fixation. Next, the lower and upper ties are installed, and then the finished trusses are lifted up and installed above the floors.

The outer trusses are attached first: using a plumb line, the rafters are aligned vertically, the length of the overhang is adjusted and attached to the mauerlat with bolts or steel plates. To prevent the truss from moving during installation, it is reinforced with temporary beams made of timber. After installing the outer rafters, the rest are set, keeping the same distance between them. When all the trusses are secured, take a board with a cross-section of 50x150 mm, the length of which is 20-30 cm longer than the length of the cornice, and nail it along the upper edge of the slope. The same is done on the other side of the roof.

The first option: a rectangular groove is cut out on the rafter leg at the point where it contacts the mauerlat, 1/3 of the width of the beam. Stepping back 15 cm from the top of the box, a steel spike is driven into the wall. The rafter is leveled, the grooves are aligned, then a wire clamp is placed on top and the beam is pulled close to the wall. The ends of the wire are securely fastened to the crutch. The lower edges of the rafters are carefully cut off circular saw, leaving an overhang of 50 cm.

Second option: the upper rows of walls are laid out with a stepped cornice of bricks, and the mauerlat is placed flush with the inner surface of the wall and a groove is cut out in it for the rafter. The edge of the rafter leg is cut to the level of the upper corner of the cornice. This method is simpler than others, but the overhang is too narrow.

Third option: ceiling beams extend beyond the edge of the outer wall by 40-50 cm, and roof trusses are installed on the beams. The ends of the rafter legs are cut at an angle and rest against the beams, secured with metal plates and bolts. This method allows you to slightly increase the width of the attic space.

Installation of layered rafters

Figure 1 shows the cutting of rafter struts into a beam laid on intermediate supports, and Fig. 2 - resting the rafter leg on the mauerlat

The procedure for installing a layered rafter system:

When the main elements are fixed, the surface of the rafters is treated with fire retardants. Now you can start making the sheathing.

For the sheathing, timber 50x50 mm is suitable, as well as boards 3-4 cm thick and 12 cm wide. Waterproofing material is usually laid under the sheathing to protect the rafter system from getting wet. The waterproofing film is laid in horizontal strips from the eaves to the roof ridge. The material is spread with an overlap of 10-15 cm, after which the joints are secured with tape. The lower edges of the film should completely cover the ends of the rafters.

Between the boards and the film it is necessary to leave ventilation gap, so first they stuff it onto the film wooden slats 3-4 cm thick, placing them along the rafters.

The next stage is covering the rafter system with boards; they are stuffed perpendicular to the slats, starting from the roof eaves. The pitch of the sheathing is influenced not only by the type of roofing, but also by the angle of inclination of the slopes: the greater the angle, the greater the distance between the boards.

After completing the installation of the sheathing, they begin cladding the gables and overhangs. You can cover the gables with boards, plastic panels, clapboard, waterproof plywood or corrugated sheeting - it all depends on financial capabilities and personal preferences. The sheathing is attached to the side of the rafters; nails or screws are used as fasteners. Overhangs are also lined with various materials - from wood to siding.

Video - DIY gable roof

21.02.2017 1 Comment

Rafter system gable roof- a simple design that even a novice developer can build with his own hands. You just need to make preliminary calculations, familiarize yourself with the details and stages of roof construction, and calculate the materials needed for installation. When making calculations, it should be taken into account that the load-bearing capacity of a gable roof depends on the influence of loads from wind, snow, and the weight of materials on it.

To make the process of building a gable roof truss system as easy as possible for you, detailed information is presented below. step-by-step instruction for installing a rafter system with your own hands.

In contact with

Classmates

Requirements for building materials

For the installation of a rafter system the best option There will be the use of lumber from coniferous wood - pine, spruce or larch, grades I - III.

The material for the rafters is taken at least grade II, the mauerlat is made from boards or timber of grade II, material of grade II is taken for racks and purlins, the sheathing is made from lumber of grades II-III, it depends on the roof. Crossbars and tie-downs are made of Grade I material. Grade III material can be used on linings and linings.

Note! The lumber must be dry with a moisture content of no more than 20%. Before installation, it should be treated with fire retardants and antiseptics against fungal diseases.

Lumber should be stored under a canopy, providing protection from the sun and moisture. Level the storage area and cover the lumber with pads for ventilation.

For installation you will need fastening elements: ties, plates, studs, bolts with washers and nuts, self-tapping screws with EPDM gaskets, 2.8 mm thick, mounting tape, galvanized brackets.

Brackets are used when attaching the Mauerlat; they are secured with nails or self-tapping screws.

KR corners serve to attach the rafters to the mauerlat and prevent the rafters from moving.

All fastening material must be made of high quality material and have corrosion protection.

Tools for constructing a rafter system

To install a gable roof rafter system, you will need the following set of tools:

• tape measures of different lengths 5, 10, 20 meters;
• markers, pencils;
• cord for tensioning;
• hammers, for various purposes, nail puller;
• scissors, for cutting;
• roofing knife;
• putty knife;
• scotch;
• hacksaws, electric saw, electric drill with various drills and attachments;
• screwdriver with attachments;
• markings, horizontal and vertical levels;
• slats, rulers;
• polyurethane foam;
• safety belt and rope - for safe work.

Keep all tools on the roof in a tool bag for safety reasons.

Types of rafter systems for a gable roof

Sent rafters

They rest on the mauerlat and racks installed on the internal wall, with a pitch equal to the rafters. To provide rigidity for spans of 6 m, additional struts are installed.

Scheme of layered rafters of a gable roof

Hanging rafters

If the building is small in width, you can arrange a rafter system where the rafters rest on the mauerlat or walls, without intermediate supports. The maximum span is 9 meters. Such roofs can sometimes be installed without a Mauerlat. The rafters are installed on the wall using spacers; in this embodiment, a bending moment acts on the rafters.

To unload, wooden or metal plates are installed. They securely strengthen the corner. For hanging rafters of a larger span, a headstock and struts are installed. For hanging systems, the rafters are made with a larger cross-section, and lumber is chosen at least grade I II.

Scheme of hanging rafters of a gable roof

Calculation of the rafter system

You can determine the cross-section of a gable roof beam required in a rafter system by collecting all the loads acting on it: the weight of the covering, sheathing, snow, wind pressure, precipitation.

Constant loads can be determined by the weight of 1 m 2 of roofing and sheathing. It is important that the weight per 1 m 2 of roofing be in the range of 40-45 kg.

Variable loads from snow and wind are calculated using table values regulatory documents SNiP, depending on the height of the building and temperature zone. The load from snow is equal to its weight multiplied by a coefficient depending on the slope of the slope. All these calculations are performed during the project.

What if there is no project and the roof is being erected on a small building? You need to look at the construction of a house in the neighborhood, which is being carried out according to a design whose roof area is the same as your building. The gable roof rafter system will serve as a model.

Dimensions of timber for rafters

At the top point a ridge is laid that connects the rafters. The height of the ridge depends on the slope of the roof. The slope is affected by the choice of coating material. The minimum sizes are:

• For tiled roofs, slate 22 gr.;
• for metal tiles - 14 g;
• ondulin - 6 g;
• corrugated sheeting - 12 gr.

Optimal angle 35-45 gr. tilt, ensures rapid discharge of water and snow. In regions with strong winds, the roofs are made flat and then the angle of inclination is within 20-45 degrees.

The height can be determined using the formula: H=1/2Lpr*tgA. Where A is the angle of inclination, L is the width of the building.

The task is simplified when using a ready-made table. The coefficient depends on the width of the building and the angle of inclination. Multiply the coefficient by 1⁄2 the width of the building.

The rafters are made from pine or spruce bars, with a section of 50x100 mm, 50x150 mm.

The size of the rafters depends on the pitch. The pitch of the rafters is smaller, a larger number is installed, and the cross-section will decrease. The distance between the rafters on a gable roof ranges from 600 mm to 1800 mm, it all depends on the design of the roof and the materials used for its construction.

Table of rafter sizes, depending on the step of their installation

Length rafters, mm	Distance between rafters, mm	Rafter beam cross-section size, mm
up to 3000	1200	80×100
up to 3000	1800	90×100
up to 4000	1000	80×160
up to 4000	1400	80×180
up to 4000	1800	90×180
up to 6000	1000	80×200
up to 6000	1400	100×200

The roof does not end at the level of the walls; it is extended outward by 500 mm. The rafter leg can protrude, or a board or block can be built up. In this case, moisture does not get on the wall and the foundation is not poured.

Step-by-step installation of a gable roof truss system

The rafter system of a gable roof consists of the following elements:

1. Mauerlat.
2. Lay down.
3. Racks.
4. Rafters.
5. Struts.
6. Puffs.
7. Lathing.

Mauerlat installation

Fastening the Mauerlat to a monolithic reinforced concrete belt

Mauerlat evenly distributes the load on the walls of the building; its installation can be done in several ways:

• attached to the wall through a reinforced concrete belt with studs;
• studs are inserted into the masonry;
• a simple and common method for simple roofs, fastening with wire rod.

For it, take timber with a cross section of 100×100 mm, 150×150 mm or 200×200 mm. Which section to choose depends on the size of the roof and its covering. The Mauerlat is joined along its length; to do this, make 100 mm cuts, 500 mm long, fold the bars and fasten them with pins.

In the corners, the mauerlat is tied with notches into the floor of the timber, fastened with staples or bolts. U wooden buildings, Mauerlat is the last crown. On brick walls, make a monolithic reinforced concrete belt with a cross-section of 400×300 mm. Along the belt, place threaded pins 12 mm in diameter, every 120 mm, for fastening.

Drill holes with a diameter of 12 mm in the Mauerlat, lay them so that the pins go into the holes. Tighten the top with nuts. First, we lay two layers of roofing felt or roofing felt under the block. On the outside of the wall, lay the mauerlat with bricks. Lay the Mauerlat on a horizontally and vertically level base. You need to check with a level that the surface is horizontal. Check diagonals. If necessary, level with pads.

Installation instructions for beds, racks, rafters, struts and tie rods

The installation of a gable roof rafter system with your own hands is carried out in the following order:

1. Install the beam with the rafters in place.
2. Mark the installation step of the rafter legs.
3. Prepare according to the size of the rack.
4. Install them if there is a need to secure them with spacers.
5. Lay the purlin. Check geometry. Install fasteners.
6. Try on the first rafter leg and mark the cutting areas.
7. Mark the points and install the rafters at the beginning and end of the roof, stretch the cord between them in order to align the remaining elements along it.
8. Having installed the rafter leg, we first attach it to the mauerlat, then to the ridge purlin, to each other.
9. Screw each second leg to the mauerlat with wire.

The rafters are fastened to the mauerlat using notches, stop corners and a hemmed support bar. Secure with nails or staples.

Methods for attaching rafters to the Mauerlat

Install the support posts on the beds or pads and overlays. A log is a beam 50×100 mm or 50×150 mm, laid on the middle wall along a layer of roofing felt. Place under the linings brick pillars, 2 bricks high.

The rafter legs are connected to each other at the ridge. Let's consider the common connection nodes of the rafter system:

1. They make cuts at one leg and cut down at the other. Insert one leg into the cut of the other and fasten with a bolt.
2. Install overlays, wooden or metal.
3. Using notches in the purlin, they are secured with nails or bolts.

Methods for connecting rafters on a ridge

To ensure the roof's resistance to wind loads, tie-rods, struts and purlins are installed. The tightening is a 100×150 mm block, purlins and struts are made from a 50×150 mm or 100×150 mm block.

With the installation of contractions, the reliability of the rafter structure increases. The sections of the timber are the same as the rafters. They are attached to the legs with bolts or nails. The device of struts adds rigidity to the structure. They are installed tightly to the surface of the rafters

Lumber has standard length 6 m. Rafters can be longer. Then you need to dock them. There are several connection methods:

1. Fasten by placing bars on both sides at the junction, connecting them with nails in a checkerboard pattern.
2. Connect with an overlap, one part of the rafters to another, at a distance of 1 meter, fasten with nails in an alternating order.
3. Make a cut obliquely, cut out part of the rafter legs, connect them, strengthening them with bolts.

Sheathing device

Lathing is installed along the roof rafters. It serves to distribute the load from roofing material and snow onto the rafters. Plays the role of an air gap between the roof and the rafter system.

The design of the sheathing depends on the roofing material used:

• under soft tiles, make the sheathing continuous, lay an anti-condensation film on the rafters, press it on top with a counter batten, nail the sheathing onto it, then OSB boards and underlay carpet, lay tiles on top.
• Under the roof made of corrugated sheets, the sheathing should be sparse. The pitch of the sheathing depends on the brand of corrugated sheeting, its thickness and the angle of inclination of the roof.
• The lathing for standard slate should be made in increments of 500 mm from a bar of 75×75 mm or 50×50, as well as boards from 30×100 mm. The design features of the roof should be taken into account when making the final choice of the appropriate option.

The lumber from which the sheathing is made is first or second grade pine. It is advisable to take the width no more than 14 cm. With a wider width, the boards may warp and damage the roofing. The length of the nails should be three times the thickness of the sheathing. Lay the boards along the ridge. Install the first board of greater thickness to the height of the roofing.

Install continuous sheathing along the roof slope.

The first layer is to place a board along the ridge from it at a distance of 500-1000 mm to the next one and so on. Lay the second layer of sheathing along the rafters. Place the joint between the boards only on the rafters at intervals. Sink the nail, head and all, into the flesh of the wood.

Cornice overhangs

They are installed to protect against precipitation and play an aesthetic role. Eaves overhangs are arranged tightly without gaps. The final stage on roofing.

Diagram of the eaves overhang of a gable roof

Gable

The gable roof has two gables. They have the shape of a triangle, with the apex at the ridge and the sides coincide with the slopes of the roof. The gables support the rafters and enclose the attic space. They protect from wind and precipitation and provide stability to the roof.

In wooden buildings, the pediment is framed. IN brick buildings, frame or brick. Gables made of brick or gas block are erected before the roofing is installed. They require very precise execution.

Frame pediments fit into the finished opening when the rafter system is already assembled.

The frame is made of bars or boards. The frame elements are connected on tenons or in the wood floor, all fastened with nails. They are sheathed by nailing boards, lining or siding, maintaining the color scheme in the decoration of the building facade. To construct a window opening, an additional frame is made under it according to the size of the window. If the attic is insulated, then the gable also needs to be insulated. The insulation is placed in the middle of the frame. Mineral wool insulation with reduced flammability is used. From the outside, the frame is covered with a hydro-windproof film or windproof membrane, With inside a vapor-proof film or a vapor-proof membrane is nailed under the finishing material.

In contact with

Roof structure

Any low-rise residential building is built so that when minimum costs materials to obtain a long service life and maximum usable space. From this point of view, of particular interest are attic spaces, allowing you to double the usable area without any additional changes. On the other hand, the design of roofs, the rafter systems of which are designed to create a residential attic, will be more complex.

Today during construction country houses Several types of roofs are used:

• Single-pitch. This is the simplest option, since here you can often do without a ridge beam and even without a number of other elements that are required in other cases. Typically, such solutions are used in construction utility rooms, extensions and garages, but they are also suitable for residential buildings with a small area.

Roofs of this type are among the most economical. They require a minimum amount of roofing material and wood, which is used for rafter structures.

• Gable. This is the second most difficult type of roof to create, since only two slopes are required here, and the rafter system, as a rule, is no different. Roofs of this type are among the most popular in modern suburban construction, because, despite their simplicity, they cope well with wind and snow loads, and are also suitable for creating an attic.
• Four slopes. This category includes hip, hip and sloping roofs. In the latter case, it is worth mentioning that we are talking about a variety gable roof, which, due to the fracture, received four slopes. Such structures are more complex than the two previous options, however, the aesthetics of the building along with them are higher.
• Gable and multi-slope. Complex rafter attachment points, special construction technology and the need for careful calculation are the reasons why such roofs are erected only by professionals. Of course, you can try to build something like this yourself, but only if you are an expert in this field.

The choice of roof type depends on the climate in the region and wind load. The second point is the angle of inclination of the slopes, which depends on the location of the building, the presence of nearby buildings or trees and the climate.

Slope angle

The ideal option for any roof is a design that requires minimal attention from the owner. Self-cleaning roofs are generally attractive because they allow you to avoid having to worry about what builds up. a large number of snow.

The accumulation of snow cannot be neglected, since its mass after intense snowfall can be up to 200 kg per m2, which means that only very strong rafters will withstand such a weight.

An alternative is the device original roof similar to alpine houses, with very steep slopes, often descending almost to the ground. It should be noted that to obtain the snow removal effect, an angle of 45 degrees is required. In this case, precipitation will roll down the surface under its own weight.
On the other hand, an increase in the slope of the slopes leads to increased consumption of roofing and building materials. Moreover, if you plan to build an attic, then the insulation will be expensive, because the higher the height of the ridge, the higher the consumption of this material. In addition to the cost of a pitched roof, the choice of slope is influenced by its type. For roofs that are not in use, it is not necessary to use a large amount of insulation, however, increasing the angle of inclination does not always justify itself.

The main sign of an unused roof is a different design of the rafter system and the absence of a gap between the ceiling and the external protective structure. Usually this flat roofs or those that have a very small slope. Their main disadvantage is that during intense snowfalls, snowdrifts can form, which will not only create a load on the ceiling, but also cause a “flood” during a thaw.

The type of roofing material will need to be determined in advance, since it must be taken into account when calculating the angle of inclination of the rafters. Typically, flexible materials and bituminous coatings are chosen for multi-gable structures. For example, metal tiles, corrugated sheets or galvanized iron. Other options, such as slate or tiles, are better suited for roofs that have a simple configuration.

Classic tiles are rarely used today, since they require a fairly large slope angle, ranging from 30 to 60 degrees.

Bituminous materials can be used even at small angles of inclination (from 8 degrees), and the limit value for them is 18 degrees. Metal tiles and asbestos-cement sheets are used at angles from 14 to 60 degrees. Under consideration roofing materials We will not go into detail, since this issue has already been covered on our website.

Expansion and non-expansion layered rafters

These are two types of rafters, one of which is chosen taking into account the shape of the house, the roof and the size of the future structure. Layered rafters are an option suitable for single- or double-pitch pitched roofs. Their main feature is that they use two fulcrum points. On one side, the rafter leg rests on the ridge of the roof, and on the other, on the wall of the house.
Non-thrust layered rafters are mounted in such a way as to avoid bursting pressure on the wall of the house. Typically, roof trusses are created using one of the following options:

• The rafter leg rests on the mauerlat. It is hemmed with a block and fixed by cutting with a tooth. In addition, additional insurance with wire is performed. The upper part of the beam is mounted on the ridge girder. Fastening is carried out using the sliding support principle.
• The bottom of the rafter is secured using a movable joint. Not only the Mauerlat, but also piece bars can be used as an installation point. The upper part is fixed with a bolt, nails or another method after it is laid on the ridge girder.
• The third option involves installing layered rafters with rigid attachment to the purlin. Nails, pins or other fasteners may be used here.

If the thickness of the rafters that was initially chosen turns out to be insufficient, then during the work you can use supports that are mounted under elements that are too long in those places where maximum deflection is expected.

Spacer rafters

Layered rafters are spacer. In this case, it is assumed that a structure will be created in which a bursting force will be transmitted to the walls of the house. The installation method in this case is the same as in the previous one, however, the fastening of the rafter legs is fixed, so the entire system will receive internal tension. It is worth saying that this option is a transitional scheme separating non-thrust layered rafters and hanging rafters.

Hanging rafters

This design of the rafter system will be ideal when it is necessary to cover large spans, the length of which exceeds 7 m. In such a situation, there is only one support point for the rafter leg - the wall. The upper part of the beam is connected to the counter element located on the other slope. Several joint options are used: half-timber, slotted tenon, metal plates.
In order for the rafter legs to be securely fixed, it is necessary to connect them using a tightening. Usually this is a strong beam that is attached to the bottom of these elements. Of course, it can be placed higher, but in this case the load will increase, which means that the weight of the beam will need to be increased. In such a situation, one of the following options for installing rafter legs can be used:

• The rafter leg is connected to the mauerlat using an additional notch and is securely held with nails. The second option involves the use of metal corners. Then the upper parts of the rafters are butt-joined, and the lower parts are held in place by a tie. In this case, the top of the rafter legs can also be pressed against the ridge purlin, which will rest on the headstocks.
• The puffs are installed so that the heels of the rafter legs rest against the cut out tooth against the edges of the puffs, which, in turn, are attached to the mauerlat. The tops of the rafters are supported with wooden planks.
• Floor beams can be used as tie-downs. In this case, their ends must extend beyond the walls by at least 55 cm. The cutting of the tooth socket is carried out no closer than 25-40 cm from the edge of the wall.
• In houses made of logs, the rafter leg is attached to the upper crown through a tenon-socket connection. Special ones can also be used metal fastenings, such as sliders, sleds, etc. The latter option will allow structural elements to move and avoid the occurrence of additional stress.

The ties themselves can be solid beams or constituent elements. The splicing of the bars is done in any convenient way, for example, with an oblique tooth, overlapping, etc. Installation of tightening can be done not only at the level of the heels of the rafters, but also in any other place.

If roof rafters measuring more than eight meters are used, we recommend creating a structure from the headstock and struts, as well as using racks and crossbars, which help increase the reliability of the rafter system.

Rafters for different types of roofs

Most simple option is a shed roof structure, the rafters of which rest on the walls of the building. The length of these elements cannot exceed 4.5 meters, but there is also a solution for overlapping large areas. In this case, it is recommended to use supports or racks that will support the extended structure.
Most gable roofs look alike like twins, but they internal structure may vary greatly. Today there are four options:

1. A ridge girder is used, on which the legs of the rafters rest. The slopes are strengthened through the use of rafter legs, and the girder is supported by racks. The racks themselves are installed on a bench. The width of this type of roof can reach 10 m.
2. The second option involves the use of rafter legs, the lower parts of which rest against the ridge girder post, and the upper parts in a grip (tightening) connecting the rafter legs closer to the ridge. In this case, the roof width increases to 14 m.
3. There is no ridge run. It is replaced by a beam located under one of the slopes. In addition, a tie, rafter legs and a stand resting on a bench are used. The angles of inclination of the rafter legs vary from 45 to 53 degrees. This option, compared to the previous one, does not provide a particular gain in roof width, but is suitable in the case when the supporting wall is not located in the center of the building, but is shifted to the side.
4. In cases where it is necessary to cover wide buildings, symmetrical structures can be used, using two purlins located parallel under the rafters of the slopes. Such gable roofs require the use of two ties, the upper of which connects the rafters, and the lower - the racks and rafter legs. The width of the structure in this case can reach 16 m.

The distance between the rafters is selected taking into account their length and cross-section. For example, for a section of 40x150 mm a step of 60 cm is required, for 50x150 - 90 cm, and for 100x150 - 215 cm.

A hip roof is another common option today that has proven itself well for country houses. It differs in that it does not have pediments, the place of which is taken by additional slopes - hips. In general, the design assumes the presence of a purlin, and ordinary rafters on the main slopes and hip rafters on the side ones. Hip rafters rest on long diagonal members where they meet the tops of regular rafter legs. For such roofs it is recommended to use reinforced piping.
The sloping roof completes the list, as it has a rather complex design. Here, a method is used that involves creating a frame for the rafter legs, consisting of a horizontal beam and vertical posts, after which the remaining elements are installed. The top crossbar of the U-shaped frame acts as a ceiling for the attic, but the ridge post also rests on it.

In this case, the distance between the rafters of the rafter system should be selected taking into account the load acting on the roof, the thickness of the timber used and the angle of inclination of the slopes.

Above we discussed the main issues related to the design of the rafter system for various types roofs, so this material can be used as a short guide to quickly understand the issues of roof construction.

The roof performs a number of important functions in creating decent living conditions, coupled with ensuring external attractiveness. It is quite reasonable that it is considered a significant structural component of the building. For the formation roofing structure meets the rafter frame. It must withstand the load, determine the configuration and be combined with the exterior of the house.

Only a well-chosen roof base can cope with the tasks at hand. Do right choice It is much easier if the owner of a country estate knows all possible types and designs of rafter systems, the specifics of their construction and scope of application are clear.

The list of roof responsibilities is not limited to protection from atmospheric influences. Although the confrontation weather events in a particular area, without a doubt, heads an impressive list of tasks.

The roof, as the final architectural touch, complements the appearance of the building, gives it a stylistic direction or completely deprives it. The rafter system as the basis of the roof structure must meet the entire range of technical and aesthetic requirements placed directly on the roof.

Factors in choosing the “backbone” of the roof

The rafter system is an indisputable accessory of pitched roofs, which:

• sets the configuration and steepness;
• holds topcoat and components roofing pie;
• creates conditions for the flawless operation of roofing system elements.

Choosing a roof ultimately comes down to determining ideal option rafter system, which, in addition to the personal preferences of the home owner, is also influenced by such compelling factors as:

• The amount of winter and summer precipitation characteristic of the area in which construction is planned.
• The strength and direction with the speed of the winds prevailing in the region.
• The owner’s desire to use the space under the roof to organize utility or residential premises.
• Type of finishing roof covering.
• Financial capabilities of the owner.

Climatic data greatly influences the choice of roof and the design of the rafter system. In regions with abundant snowfall, it is not advisable to erect structures with a slight steepness, which contributes to the formation of snow deposits. In areas with gusty winds, on the contrary, streamlined and low-sloping shapes are preferred, which will be difficult to be torn off and carried away by a powerful weather phenomenon.

It is clear that the flat design is not adapted to the device in it useful premises. For those wishing to equip the space under the roof, there are rafter systems designed for construction in regions with varying degrees of wind loads.

If there is no need to use an attic, a roof of a complex or simple configuration can be built without it. There are a lot of options, including various combinations of basic versions, familiarization with which will give an idea of ​​​​the essence of building a rafter system of any type.

In order not to suffer from guessing about the most rational shape and angle of inclination of a pitched roof, it is enough to take a closer look at the surrounding low-rise buildings.

The proven configuration can be safely taken as a basic option in order to adjust and modify it in accordance with the requirements of the future owner and the technical characteristics of the roofing. If you don’t want to copy your neighbors, you should familiarize yourself with the design and operational specifics of various rafter systems.

Basic options for rafter systems

A pitched roof can be simplistically represented as a set of slopes - planes along which atmospheric water “rolls”. The slopes are formed by the ribs of the rafter legs - the main elements of the rafter system. The classification of pitched roofs and their corresponding rafter systems is made depending on the number and configuration of the slopes. According to the indicated characteristics, their ranks include:

• Single-pitch. Roofs with one slope are installed mainly over utility buildings, extensions, and verandas. rest on two walls or two rows of racks. One of the walls or one row of supports must be higher than the other so that water can flow along the plane formed by the rafters without obstacles.
• Gable. Roofs with two rectangular slopes are most often found in domestic spaces. Rafter legs gable systems rest on two walls of a rectangular box of the house. In the classic design, the area of ​​both slopes is equal, as is the height of the supporting walls. True, they have often become design solutions with slopes of different areas and supporting walls of different heights.
• Hip. Otherwise called hipped, based on the number of pitched planes. The rafter legs of the hip system form a pair of trapezoidal and a pair of triangular slopes. The rafters of the trapezoidal components rest on the long walls of the box, and the triangular ones rest on the short end walls. In plan, the hip roof looks like a postal envelope. Looks impressive and can be used everywhere. The hipped category includes roofs with shortened triangular slopes, which are strongly recommended for construction in areas with high wind loads.
• Tent . A roof that consists of triangular slopes converging at one vertex. Minimal amount 4 slopes, unlimited upper limit. Rafters tent system rest on walls or supports of equal height. They prefer to erect tent structures over verandas and gazebos. Variations in the steepness of hipped roofs allow them to be installed in regions with any wind load.
• Broken. Also called attic, because it is broken technology allows you to create the most spacious rooms under the roof. Rafter legs of broken structures are installed by analogy with gable systems, but are constructed in two tiers. The lower rafters rest on the walls of the box being equipped, the upper ones on the supports of the lower tier of the rafter frame.

The listed types of roofs and rafter structures have numerous variations on the pitched theme. For example, a gable roof may have a regular gable gable at one end and a hip at opposite side or be supplemented single-pitch construction above the porch in the middle of the main slope.

When two gable systems are combined crosswise, a composite roof with four wooden gables or stone gables is formed. In the arrangement of boxes with a T-shaped or L-shaped configuration, several types of rafter systems are often involved simultaneously. Upper tier sloping roof can be built using hip technology.

A truss structure of any complexity can be represented as a set simple shapes. To make it easier to understand the intricacies of construction, it is better to conditionally divide the object into separate blocks. They will tell you how to build each of the parts and connect the basic types listed above to each other rafter frames.

Overview of pitched rafter structures

In order to understand the abundant variety of structures and the possibilities of their layout, we will consider the main types of rafter systems and the corresponding diagrams.

Type #1 – lean-to rafter frame

Majority pitched roofs belongs to the category of roofless ones, because regardless of the steepness, the space they create under the roof is not large in volume. However, if you want to build a strictly horizontal ceiling, a ceiling separating the attic from the main rooms is still built.

The scheme depends on the size of the span to be covered with a single slope:

• If the distance between the upper and lower supports of the rafter leg is less than or equal to 4.5 m, additional struts and racks are not used.
• If the span is in the range from 4.5 m to 6 m, a bench is laid near the high wall. A strut is rested against it - a rafter leg that ensures the rigidity of the rafter closer to the top of the span.
• If a span of 6m to 9m is to be covered, the beams are laid on both sides and the rafter legs rest against both beams.

If it is necessary to cover a larger span, it is divided into sectors with the distances indicated above. At the border of adjacent sectors, racks for purlins are installed, and within the sector, beds and struts are installed according to the described rules. For construction in regions with high wind activity, single-pitch rafter structures are supplemented with diagonal wind braces from the inside.

In plan, the diagram of a single-pitch rafter frame resembles a series of parallel beams. A roof with one slope is not very beautiful, but it is very economical. The optimal angle of inclination is from 4º to 12º, and a greater inclination is not prohibited.

It is advisable to equip structures with low slopes with continuous sheathing and waterproofing, which is not necessary for steep roofs. As a finishing coating, it is better to use for low structures, corrugated sheets or roofing metal for arranging steeper structures.

Type #2 – rafter systems for gable roofs

Gable rafter frames are built on reinforced concrete floors and wooden beams, mainly with attics. The most common type of roof has a huge number of low and high, insulated and cold modifications.

Depending on the architectural and technical conditions of the object, rafter legs used in the installation of gable roofs are divided into:

• Layered. These are rafters that have a strong support under the upper and lower heels. They are manufactured and installed like the rafters of pitched roofs. Layered rafter systems are constructed over boxes with internal load-bearing wall. She is needed as supporting structure under the ridge run. The role of a wall can be played by a number of supporting posts or columns. In the simplest layered scheme with a span of up to 5 m, the tops of the rafters rest on a purlin, which rests on a beam through support posts. Rigidity is provided by struts. Schemes for more substantial spans are equipped with contractions, headstocks and additional runs.
• Hanging. Rafters hanging type They have only lower support; their tops rest against each other. The elements of the hanging rafter frame are immediately made in the shape of a triangle, so you can dispense with the Mauerlat. In such cases, the function of the Mauerlat is trusted to the base of the triangle - a tightening used to compensate for the thrust on the roof from the weight of the snow, the roof and the system itself. Hanging technology is used in the arrangement of small boxes that do not have internal support for ridge run. If it is necessary to cover long-span structures, the hanging system is equipped with headstocks, struts, tie rods, etc.

Depending on the technical characteristics of the roof, the sheathing is arranged continuous or sparse. Low slopes up to 12º are completely covered with a waterproof carpet, high ones - only in places of possible leaks: along the eaves, ridge, valleys, around pipes and other roofing passages.

Type #3 – hip and half-hip system

Hip, or “envelope” roofs, differ from gable structures in that the place of vertical gable gables in their structures is occupied by inclined triangular slopes - hips. Central part The roof is occupied by a standard gable rafter system, to which the same hips adjoin at an angle.

Diversity in the family of hip structures is achieved through variations with proportions. By changing the ratio of the length of the ridge to the length of the base and the height of the slope, you can get a design that meets any taste and architectural needs.

In the construction of rafter frames the following are used:

• Layered or hanging trusses with corresponding structural elements: beams, ridge purlins, tie rods, etc.
• Diagonal rafters connecting the tops of the outer trusses to the corners of the box.
• Sloping shortened rafters that form inclined slopes of the hips and parts of the main slopes adjacent to the hips.

Hip structures can be attic or non-attic. I must admit, they are not very suitable for organizing rooms under the roof. Four inclined slopes seriously limit the space. However, for lovers of attic houses there is a Danish variety with a shortened hip. Adherents of non-standard architecture will certainly like the Dutch type, which belongs to the category called “” along with the Danish version.

Rafter systems for hip and roof types are erected with an angle of inclination from 10-12º to 60º. The absolute priority is the classic proportions with a slope of 25-30º.

In addition to penetrations, ridges and eaves overhangs, all convex and concave corners of the hip structure need enhanced waterproofing. The complex configuration of the slopes dictates the use of piece materials in finishing. When cutting metal tiles and corrugated sheets, there will be too much waste.

View #4 – hip roof

Simple hipped tent structure represents hip roof devoid of a ridge part. Its plan layout resembles a square with diagonals running from corner to corner. Triangular slopes are connected at one vertex, which makes the roof similar to a tent. Build over boxes of a clear rectangular or polygonal shape.

In the construction of hip rafter systems, standard layered and hanging principles are used:

• A rafter structure of the layered variety is erected above the box with a central support or load-bearing wall.
• A frame is erected over an object without an internal wall or support using the hanging principle.

The steepness and number of slopes depend on the personal preferences of the future owner. The ideal roofing covering for finishing triangular slopes would be piece material, solely because when cutting large sheets, an impressive amount of waste remains. Regardless of the steepness, they prefer to equip tent structures with continuous lathing and a waterproofing carpet.

View #5 – broken rafter system

Rafter frames for broken lines, i.e. are specifically focused on increasing the attic space in order to create domestic or residential premises in it.

Framed technology is mainly used in the construction of attic roofs, which can be cold in country houses and insulated in permanent residences.

Each slope of a classic sloping roof can be divided into two rectangular parts, creating an external angle between them. The required shape is obtained by changing the sizes of the parts of the slopes, the angles between them and the angle in the ridge zone.

The attic-type rafter system is one of the most complex species rafter systems: diagrams and drawings of a broken frame introduce the complex structure of the structure. It consists of two tiers perched on top of each other:

• The lower tier of rafter legs rests through the Mauerlat on wooden floor beams, reinforced concrete slabs or ceiling beams wooden house. To support the top of the rafters, purlins are installed, which also serve as support for the bottom of the rafters upper tier. The rafters of the lower part of the sloping roof are only allowed to be layered.
• The upper tier of rafters rests with their lower heels on the purlins of the tier located underneath. The purlins serve as the basis for laying ceiling beams attics. In the construction of the upper part, both layered and hanging methods can be used. The task of the top is only to form the ridge part, because the responsibilities for distributing the roofing pie are assigned to bottom part mansard roof.

The owner chooses the angle of inclination of the lower and upper parts of the slopes according to his own preferences. Ideal shape count if five corners are intersected by an imaginary circle. Solid or sparse sheathing is installed depending on the type of roofing, and there are no restrictions on its choice at all.

It is better to install continuous sheathing and waterproofing on the flatter upper part. On the steep lower part of the slopes, precipitation does not linger, but it is threatened by heavy winds.

To prevent the sloping roof from falling off in areas with frequent strong winds, each rafter is attached with a wire bundle to the wall, and not through one, as is customary when fixing conventional pitched roofs.

Video review of types and shapes of roofs

Expert Tips:

Photo selection (slideshow):

The presented diagrams of different types of rafter systems are suitable for arranging a wooden house, brick and foam concrete frame. The only difference is in the fastening of the Mauerlat on wooden and stone walls. Information about the basic types of rafters will help you correctly determine the type and configuration of the roof for a country property.