Rafter installation technology. How to make a truss system with your own hands. Types of gable roof

21.02.2017 1 Comment

truss system gable roof- a simple design, accessible for a do-it-yourself device even for a novice developer. It is only necessary to make preliminary calculations, familiarize yourself with the details and stages of the construction of the roof, and calculate the materials needed for installation. When calculating, it should be taken into account that load bearing capacity gable roof depends on the influence on it of loads from wind, snow, weight of materials.

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

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Requirements for building materials

For the device of the truss system the best option will use lumber from coniferous wood - pine, spruce or larch, I - III grade.

The material for the rafters is taken not lower than grade II, the Mauerlat is made from boards or timber of grade II, for racks and girders material of grade II is taken, the lathing is made from grade II-III lumber, it depends on the roof. Crossbars, puffs are made of Grade I material. On linings, linings, material of grade III can be used.

Note! Lumber must be dry with a moisture content of not more than 20%. Before installation, it should be treated with flame retardants and antiseptics against fungal diseases.

You need to store lumber under a canopy, providing protection from the sun and moisture. Level the storage area, shift the lumber with linings for ventilation.

For installation, fasteners are required: 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 fastening the Mauerlat, they are fastened with nails or self-tapping screws.

KR corners serve to attach the rafters to the Mauerlat, prevent the rafters from moving.

All fixing material must be made of high quality material and protected against corrosion.

Tools for the construction of the truss system

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

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

Keep all roofing tools in a tool bag for safety.

Types of truss systems for a gable roof

sent rafters

Rely on Mauerlat and racks mounted on inner wall, with a step equal to the rafters. To give rigidity during spans of 6 m, struts are additionally placed.

Scheme of layered rafters gable roof

hanging rafters

If the building is of a small width, it is possible to arrange a truss system when the rafters rest on the mauerlat or walls, without intermediate supports. The maximum span is 9 meters. Such roofs can sometimes be arranged without a Mauerlat. The rafters are installed on the wall, using gaskets, on the rafters in this embodiment, a bending moment acts.

To unload, put wooden or metal lining. They securely reinforce the corner. For hanging rafters of a larger span, a headstock and struts are installed. For hanging systems, the rafters are arranged with a larger section, and the lumber is chosen not lower than grade I II.

Scheme of hanging rafters of a gable roof

Calculation of the truss system

It is possible to determine the cross-section of a gable roof beam in the truss system by collecting all the loads acting on it: the weight of the coating, lathing, snow, wind pressure, precipitation.

Permanent loads can be determined by the weight of 1 m 2 of roofing, battens. It is important that the weight per 1 m 2 of the roof is in the range of 40-45 kg.

Variable loads from snow, wind are calculated from tabular values normative documents SNiP, depending on the height of the building, 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 carried out during the project.

And 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 the project, the roof area is the same as your building. The gable roof truss system will serve as a model.

Rafter beam dimensions

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 influenced by the choice of coating material. Minimum dimensions are:

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

The optimal angle is 35-45 gr. slope, provides a quick 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.

You can determine the height by the formula: H \u003d 1 / 2 Lpr * 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 of the width of the building.

The rafters are made from pine or spruce bars, with a section of 50 × 100 mm, 50 * 150 mm.

The size of the rafters depends on the pitch. The pitch of the rafters is smaller, a larger number is installed, the cross section will decrease. The distance between the rafters at a gable roof is in the range 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 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 500 mm outwards. The rafter leg can protrude, or a board or bar is built up. In this case, moisture does not fall on the wall, the foundation is not poured.

Step-by-step installation of the design of the gable roof truss system

The gable roof truss system consists of the following elements:

1. Mauerlat.
2. Lie down.
3. Racks.
4. Rafter.
5. Struts.
6. Puffs.
7. Crate.

Mauerlat installation

Mauerlat fasteners 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:

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

For him, take a bar with a 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 coverage. The Mauerlat is joined along the length, for this, make a 100 mm cut, 500 mm long, fold the bars and fasten with studs.

In the corners, the Mauerlat is tied with cuts to the floor of the beam, fastened with brackets or bolts. For wooden buildings, Mauerlat is the last crown. On the brick walls, perform a monolithic reinforced reinforced concrete belt, with a section of 400 × 300 mm. Align the pins with a thread of 12 mm in diameter along the belt, through 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 with nuts from above. Previously, we lay two layers of roofing material or roofing felt under the bar. On the outside of the wall, lay the Mauerlat with bricks. Laying the Mauerlat on a horizontally and vertically even base. It is necessary to check the horizontal level of the surface. Check diagonals. Align with pads if necessary.

Installation instructions for beds, racks, rafters, struts and puffs

Do-it-yourself do-it-yourself installation of a gable roof truss system is carried out in the following order:

1. To carry out the installation of the bed, with the sent rafters.
2. Mark the installation step of the rafter legs.
3. Prepare according to the size of the rack.
4. Install them, if necessary, unfasten them with spacers.
5. Lay a run. Check geometry. Install fastener.
6. Try on the first rafter leg, mark the cutting points.
7. Mark the points and install the rafters at the beginning and end of the roof, pull a cord between them in order to align the rest of the elements with it.
8. Having installed the rafter leg, we attach it first to the Mauerlat, then to the ridge run, to each other.
9. Screw every second leg with wire to the Mauerlat.

The fastening of the rafters to the Mauerlat is done with the help of notches, thrust corners and a hemmed support bar. Reinforce with nails or staples.

Methods for attaching rafters to the Mauerlat

Install the support posts on the beds or linings and linings. A bed is a beam 50 × 100 mm or 50 × 150 mm, laid on the middle wall along a roofing felt lining. Place brick columns under the lining, 2 bricks high.

The rafter legs are connected to each other on the ridge. Consider the common connection nodes of the truss system:

1. They make cuts at one leg and washed 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. With the help of cuts in the run, they are fixed with nails or bolts.

Methods for connecting rafters on a ridge

For the stability of the roof to wind loads, puffs, struts and runs are installed. The tightening is a bar 100 × 150 mm, runs and struts are made from a bar 50 × 150 mm or 100 × 150 mm.

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

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

1. Fasten by applying bars on both sides at the junction, connect them with nails in a checkerboard pattern.
2. Overlap, one part of the rafter to another, at a distance of 1 meter, fasten with nails in a variable order.
3. Run a cut obliquely, cut out part of the legs of the rafters, connect them, reinforcing them with bolts.

Lathing device

A crate is laid along the roof rafters. It serves to distribute the load from the roofing material, snow on the rafters. It plays the role of an air gap between the roof and the truss system.

The design of the crate depends on the accepted roofing material:

• under the soft tiles, the crate should be made continuous, an anti-condensate film is laid on the rafters, it is pressed against the top with a counter rail, the crate is nailed onto it, then the OSB boards and the lining carpet, the tiles are laid on top.
• under the roof of the corrugated board, the crate should be sparse. The step of the lathing depends on the brand of corrugated board, its thickness and the angle of the roof.
• make a crate for standard slate in increments of 500 mm from a bar 75 × 75 mm or 50 × 50, as well as boards from 30 × 100 mm. It is necessary to take into account the design features of the roof, with the final choice of a suitable option.

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

To arrange a continuous crate along the slope of the roof.

With the first layer, lay a board along the ridge from it at a distance of 500-1000 mm next, and so on. With the second layer, lay the crate in the direction along the rafters. Arrange the joint between the boards only on the rafters in a run. The nail is sunk completely with the head into the pulp of the wood.

Cornice overhangs

Arranged to protect against precipitation, play an aesthetic role. Eaves overhangs suit tightly without gaps. The final stage in the construction of the roof.

Scheme of the device 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. Gables support the rafters and enclose the attic space. Protect from wind and precipitation, give stability to the roof.

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

Frame gables fit into the finished opening when the truss system is already assembled.

The frame is made of bars or boards. The frame elements are connected on spikes or to the floor of a tree, all fastened with nails. They are sheathed by nailing boards, lining or siding, maintaining the color in the decoration of the facade of the building. For the device of a window opening, an additional frame is made under it according to the size of the window. If the attic is insulated, then the pediment also needs to be insulated. Insulation is laid in the middle of the frame. A mineral wool insulation with reduced flammability is used. From the outside, the frame is upholstered with a hydro-windproof film or a windproof membrane, from the inside, a vapor-tight film or a vapor-tight membrane is nailed under the finishing material.

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During the construction of private houses, the roof is most often made gable. There are reasons for this. First, it is reliable. Handles wind and snow loads well. Second, it is compatible with any roofing. The third is relatively inexpensive. The fourth is a simple design that is difficult to spoil. Fifth - it looks attractive. All this, and also the fact that a do-it-yourself gable roof is built without special knowledge, determines its popularity.

Do-it-yourself assembled gable roof ready for installation of roofing

Step-by-step installation of a gable roof

As you saw above, there are a lot of truss systems. Accordingly, when assembling each has its own characteristics, but in general the order is the same. It is necessary to say about the general step: pre-drying and processing of wood. This step is required if you bought fresh lumber, not dried.

The use of raw wood of natural moisture in the construction of the roof will lead to problems: the beams will bend, they will dry out, the geometry will change. All this will lead to the emergence of stress points and at the slightest sign of overload (a lot of snow, strong wind or rain), negative processes will begin. Their elimination is a complex and costly undertaking. Therefore, either buy dry wood (no more than 20%, ideally chamber drying 8-12%), or buy material a couple of months in advance, put it in ventilated piles. After that, treat with the necessary impregnations (from fungal attack and to reduce flammability) and only after that use it in the installation of the truss system.

Timber must be dried in ventilated stacks. To do this, they are laid in short pieces of boards. They are placed a meter from the edges and further through the meter. Spacers must be installed under the bottom

We will talk about the main stages of assembly, about how to make a gable roof with your own hands in this section.

Mauerlat

The assembly of the gable roof truss system begins with the installation of the Mauerlat. It must be set strictly horizontally, therefore, before starting installation, the horizontalness of the wall to which it is attached is carefully checked, if necessary, it is leveled with cement mortar. You can continue work after the solution gains 50% strength.

Depending on the system, this is a beam with a section of 150 * 150 mm or a board with dimensions of 50 * 150 mm. It is attached to the top row of masonry walls. If the house is wooden, its role is played by the upper crown. If the walls are made of light building blocks - foam concrete or aerated concrete and others - their rigidity is not enough to redistribute the load. In this case, a reinforced concrete belt is made over the last row of masonry, into which embedded fasteners are embedded - wire or studs. A bar or board is then mounted on them.

There are several ways to connect walls and Mauerlat:

• In the masonry (in the reinforced concrete belt) a smooth rolled wire of large diameter is fixed (two ends stick up). The board is then rendered in necessary places holes through which the wire is threaded. She then twists and bends.
• Studs with a diameter of at least 12 mm are immured in the wall. Under them, holes are made in the Mauerlat, a beam / board is placed) and tightened with nuts with wide washers.
• Aligning the beam or board along the outer or inner edge of the wall, take a drill with a diameter of 12 mm, make holes for the anchor bolts. They (the same diameter of 12 mm) are hammered to the very hat, then tightened with a key.

The distance between the studs (wire) should not be more than 120 cm. Cut-off waterproofing must be laid on the wall (belt) under the Mauerlat. It can be rolled roofing felt or waterproofing in two layers, it can be smeared with bituminous mastic.

Rafter installation

There are more than a dozen types of gable roof truss systems. First of all, you need to choose what yours will look like. Further, in order to make it easier to work, a template is made from thin boards for all cuts, cuts and other similar details. To do this, you may need to assemble the first form on the roof, and then make templates for the finished one.

The assembly order depends on the type of truss system. If the rafters are layered, they are installed gradually, assembling from the elements directly on the roof. In this case, it is convenient if the beams of the ceiling are laid and, if possible, the draft flooring of the attic or attic.

In systems with hanging rafters, a farm is assembled on the ground - a ready-made triangle of puffs and rafter legs with all the required struts, racks. The required number of farms is assembled at once. Then they are lifted to the roof, placed vertically there and attached to the Mauerlat.

On the one hand, this is convenient - it is easier to work on the ground, with a high assembly speed, the accuracy is high: one farm is not much different from the other, which simplifies the procedure. But it can be difficult to raise finished trusses, especially for large buildings. To make this easier, two inclined boards are installed, which at one end rest against the ground, and the other sticks out a little above the wall. Farms are brought closer to this “lift”, one by one they are installed below, ropes are tied and pulled along the boards to the roof. In the absence of a winch or crane, this is the most acceptable method.

The assembly of rafters requires certain knowledge: how and in what order to mount them, how to mark and make cuts. See the video for the assembly of one of the schemes with a headstock.

Assembly order of the truss system

Everything, the do-it-yourself gable roof is assembled and ready for installation of roofing material.

The process of installing the rafters itself raises enough questions, but there are many ways and it is impossible to tell about them all. See one of them in the video. The system is large and went up to the roof in parts, and there it was already assembled into a single structure. It is convenient for large houses.

Features of the installation of the truss system of a wooden house

The difference between wooden houses is that the log house shrinks, and this leads to a change in the geometry of the truss system. If the elements are fixed rigidly, the roof may fall apart. Therefore, the mounts are made floating. There are special sliding fasteners, which in this case attach the rafters to the upper crown and to the girders, if any (see photo).

In order for the rafter to move freely during shrinkage, its long part is fixed strictly parallel to its edge, and the support is placed strictly perpendicular. If necessary, a platform is cut out under it. Mark the mount so that the hook is in the lowest position or near it. They are mounted on special self-tapping screws that come with the kit (ordinary ones do not fit). If the installation is done on a log, so that the rafter leg does not slip along it, a semicircular hole is cut out in the lower part, on which it will rest.

Such fasteners are sold on any construction market, it is called "slippery". How to attach the slippery to the timber, see the video.

Video on assembling and installing a gable roof truss system

It is not easy to build a gable roof with your own hands: there are a lot of subtleties and nuances, there are different ways of fastening, building up. Describing them in words is a thankless job. This is the case when it is better to see. Below is a selection of videos that you might find useful.

Video report on how a gable roof is made

The story of the owner of the house about the stages of construction. There are interesting technical points that may be useful.

Two types of rafter connection: rigid and sliding

Video about the two most problematic types of connections.

How to determine the angle of the rafters

Full video report on the assembly of the truss system

This movie is just under an hour long, but the entire process is shown from start to finish with plenty of detail. The roof is placed on, but when installed on buildings of a different type (except for wooden houses), there is no difference.

Building your own home is always a waste: starting from the project and ending with its implementation, you can’t do anywhere without the help of professionals. But is it really so? Isn't it possible to do most of the work with your own hands? You can, if you use the tips from our site!

There is a lot on the resource, how about a reliable foundation for any building. But, in addition to a stable foundation, the coziness and comfort of staying in the house is affected by that which does not leak and helps to keep the heat in the room.

Any roof structure cannot do without high-strength rafters, and their assembly is one of the most time-consuming tasks in the construction of a monolithic or private house. A frame for a new roof can be bought at the nearest woodworking sawmill, and you can install it yourself, observing all the technological requirements and features of different configurations. Next, consider the main elements and methods for installing rafters on the roof of a private house.

Roof structure elements

Mauerlat- the main component of the entire system, a kind of foundation, which is installed along the perimeter of the walls and creates an optimal load balance, protecting the structure from involuntary movement at the time of strong winds or heavy rainfall. Mauerlat can be made from planed timber, in some houses it can be replaced by the upper wall trim.

rafter legs- designed to hold a kind of sandwich. A sheet of sealant is laid between the supporting rafters, and a crate is placed on top of it.

Runs- solid beams that are laid in level along the roof. Used to fix rafter legs. They are divided into several types: ridge run (located in the upper part of the roof), lateral (located in the center of the supporting legs of the rafters).

Racks- take on a small weight of the structure. They are used to strengthen the stops of the rafters and the ridge.

Struts- are installed specifically to hold the rafter legs. Mounted in an inclined position. Gives the building extra strength.

Installation of the truss system

In order to start installation work on the construction of the roof of a private house, it is advisable to familiarize yourself with the theoretical part, from which you can learn how to properly install the rafters on brick or wooden walls. Consider the most common sequence for installing the elements of the truss system.

Mauerlat installation

Before laying the mauerlat on wooden walls, you can add one log at a time around the entire perimeter to increase the height of the ceiling. Under the upper logs, which will be the base, it is advisable to put a knitting wire, with which it will be attached to the base of the wall. An easier way is to secure the base with large anchor bolts.

First comes a waterproofing film or roofing material. Next, lay out the finished workpiece around the entire perimeter of the walls. In some cases, the length of the bars may be less than the walls, in which case they must be leveled.

How to connect mauerlat

After installation, we check the geometry. For this operation, a laser level is ideal.

This operation should not be neglected - the slightest inaccuracy of 1-2 cm threatens with poor-quality assembly of the entire truss system, which can lead to unplanned roof repairs as early as next year.

Good to know. by the most in a simple way check is considered a rope or fishing line. With their help, you can measure the distance of one diagonal (from one corner to the opposite), fix and compare with another, and if the result matches, then everything is done correctly.

We fix the corners of the Mauerlat.

We fix the entire structure with wire, anchor bolts or studs. For fastening with studs and anchors, holes must be made in advance. A low-speed electric drill can easily handle this. Screwing the bolts is best done in several stages, alternately on each side.

We make the correct installation of rafters

rafters

Before proceeding with the installation of rafters, it is advisable to decide on the type, there are only two of them - a hanging installation of roof rafters and an inclined one. Their main task is to fasten and hold all the elements, and the difference is the number of supports.

Inclined have 2 or 3 pcs. For small buildings with small spans, an inclined rafter installation system is used. Gable are used for domestic or public premises, which are endowed with additional, load-bearing partitions and columns.

In the area of ​​\u200b\u200bthe base of the beam, the rafter legs should fit snugly against the Mauerlat, and at the top - into the ridge run, which is mounted on racks mounted on the lower run. The connection is best made on pre-prepared cuts with metal clamps or staples.

Hanging lean on load-bearing walls in two places, additional props are not used.

Therefore, if the planned slope is less than 45 degrees, the horizontal pressure will be greater than the vertical one, which means that it is worth considering emergency reinforcement. Therefore, it is necessary to carry out all the calculations before starting work and decide how to install the rafters in your case.

Rafter system for the future attic

The most common method of fastening are ties made of metal or wooden structures. The place of their installation is selected individually and directly depends on the desired functionality of the attic space. For example, if the roof will be used in the role, the screed should be at the base of the rafter legs.

Installation of load-bearing rafters for a gable roof

To create a reliable fastening of the entire roof, which can withstand heavy loads, you must use the combined installation method, i.e. installation of rafters will take place using two technologies - inclined and hanging.

For installation, high-quality beams with antiseptic treatment are best suited. The most common size is 49.9 * 149 * 5000 mm. If the length of the beam is greater than specified, it is advisable to increase the height of the carrier beam to 180 mm. The installation of the rafter system should be carried out in a parallel manner, that is, having mounted the rafter on one side, we immediately set it on the opposite side.

Preliminary marking and drilling of holes for fastenings is best done on the ground.

In order for the supports to be as stable as possible, it is advisable to make the lower grooves according to the diameter of the Mauerlat.

Having selected the upper section of the intersection, we proceed in the same way and make a tie-in equal to half the diameter of the beam.

When fastening with an overlap, the top fastening should be obtained without additional protrusions.

In order for all the grooves to be of the same diameter, it is necessary to prepare a mortise template. The most common material for its manufacture is plywood or thick cardboard. According to a previously drawn up drawing, a layout is cut out of plywood in two copies, nailed to a beam on both sides and outlined with a pencil. The tie-in made according to this principle will turn out to be dense and as even as possible.

It is desirable to make cuts as simple as possible, since intricately cut joints can be absolutely unreliable.

As far as possible, the mounted planes should be perpendicular to the load forces that may appear along the wooden elements.

After creating the structure, it should be securely fixed to the Mauerlat. For this, ordinary nails or special anchors are suitable. The next step is to determine the minimum distance of the rafters from each other.

To determine it, look at the table.

Rafter leg length, m	Distance between adjacent rafters, cm
	110		140		175		213
	Rafter leg thickness, cm
	bars	logs	bars	logs	bars	logs	bars	logs
Less than 3	8 * 10	Ø 10	8 * 13	Ø 13	9 *10	Ø 10	9 * 16	Ø 16
3 to 3.5	8 * 13	Ø 13	8 * 16	Ø 16	8 *18	Ø 18	9 *18	Ø 18
3.6 to 4.2	8 * 16	Ø 16	8 * 18	Ø 18	9 *18	Ø 18	10 *20	Ø 18
4.2 to 4.9	8 * 18	Ø 18	8 * 20	Ø 20	10 *20	Ø 20	–	Ø –
4.9 to 5.7	8 * 20	Ø 20	10 * 20	Ø 20	–	Ø –	–	Ø –
5.7 to 6.2	10 * 20	Ø 20	12 *22	Ø 22	–	Ø –	–	Ø –

Trying on rafter legs

Below we consider the main aspects that will affect the choice of the section of the rafter leg:

• We find out what will be the constant pressure on the bars.
• Covering material used in a particular case.
• The desired angle of inclination of a shed or gable roof, which is easy to calculate if you use the advice from.
• Dimensions of the house and the estimated complexity of installation.
• Climatic conditions in your area. The calculation is the level of precipitation in summer and winter.
• The material and quality of the rafters themselves. The best option would be bars obtained from coniferous trees. But sometimes you can stumble upon a fake, so it is better to select higher quality varieties so that the wood can be used to determine the natural origin of the material.

The main characteristic of the wood used is its moisture content. A suitable level should be within 22 percent. If you wondered how to install rafters with high humidity? The answer is no! They need to dry well. The whole reason is that excessive moisture will evaporate over time, and the wood will shrink, which will lead it to deformation and change in size, and this can lead to more negative consequences, for example, a violation of tightness.

Let's move on to the legs. There are several reliable fasteners in use today. They can be used on all types of roofs. The reliability and correctness of attaching the rafters to the Mauerlat will depend on their execution:

• sliding;
• Rigid.

For both cases, you can use a varied combination of hanging and inclined rafters.

hard way it is used for standard structures that are installed without turns, bends. To use it, it is advisable to put risks on the bars in advance and make the appropriate cuts, followed by attaching the rafter leg to the Mauerlat.

sliding(very often called free mount) has several stages of fastening. This is done in order to leave a certain margin for the subsidence of the frame; it can be used in conjunction with poorly dried rafters.

It is difficult to overestimate the value correct installation rafters for the stability and durability of the roof.

Thus, by applying the basic knowledge gained from this article, you can not only control the process led by professionals, but also do most of the work yourself, while significantly reducing costs and saving time and nerves.

Good luck with your construction!

According to statistics, every second homeowner built his home on his own. According to their reviews, self-erecting a roof is one of the most difficult stages for non-professional builders. Therefore, it is very important to approach this stage, having in mind a complete understanding of all the nuances of the process. To figure out how to make a roof with your own hands, you need to study the device, installation technology, the procedure for work and the features of fastening all components of the structure.

Roof types

First you need to decide on the form. To date, the most popular types are:

Form Features

Covering the roof with one single slope will save nerves and materials, since structurally this is the simplest option. If you make such a frame yourself, then the labor intensity of the work will be the least, and the installation speed will be high. But this form has a drawback - there is no possibility of arranging a full-fledged attic or attic, since the under-roof space is too low.

A gable roof is mounted much more often. It is a little more difficult to manufacture, but allows you to get more space. Compared to the four-slope, it has less complexity and mass, but it will be necessary to make triangular gables along the ends of the building.

Gable - the most popular form

Before proceeding with the independent construction of a roof with four slopes, you will need to seriously prepare. Such a system has more elements than the previous two. In addition, there is no way to make full-fledged windows in the attic, since the roof structure is devoid of gables and installation is difficult or unavoidable.

The four-slope is difficult to construct, but savings are achieved due to the absence of gables

For an attic, a combined design with. In this case, the lower part of the roof has a greater slope than the upper part. This assembly allows you to raise the ceiling in the room and make the house built more comfortable.

A broken line is not the most “architectural”, but very efficient in terms of space used

Calculation

Before starting work, you need to make a design calculation. It makes no sense to calculate sections of all elements. In most cases, they can be accepted constructively:

• mauerlat - 150x150 mm;
• racks - 100x150 or 100x100 mm, depending on the section of the rafters;
• struts - 100x150 or 50x150 mm, taking into account the convenience of connecting with rafters;
• puffs - 50x150 mm on both sides;
• runs - 100x150 or 150x50 mm;
• pads with a thickness of 32 to 50 mm.

The calculation is usually performed only for rafter and sloping legs. It is required to choose the height and width of the section. The parameters depend on:

• roofing material;
• snow region;
• the pitch of the rafters (selected so that it is convenient to lay the insulation, for mineral wool between the elements, 58 cm should remain in the light);
• span.

You can choose the cross section of the rafters using general recommendations. But in this case, it is recommended to make a small margin.

The calculation is usually performed for rafter legs

If you do not want to delve into the intricacies of calculations, you can use special ones.

If you intend to make a warm roof, then the height of the section of the legs is selected taking into account the thickness of the insulation. You need to mount it so that it does not protrude higher bearing beams. You also need to take into account that for mineral wool a ventilation gap of 2-4 cm is made between it and the coating. If the height of the rafters is not enough for this, the installation of a counter-lattice (counter-rail) is provided.

Step-by-step instructions for performing work

The sequence of stages of the construction of the roof is as follows:

1. taking measurements of the building box (the dimensions may slightly differ from the design ones);
2. preparation of materials and tools, wood treatment with an antiseptic;
3. fastening the Mauerlat to the wall;
4. installation of a ridge crossbar, if needed (for layered rafters);
5. frame installation;
6. strengthening the roof with the help of racks, struts and puffs;
7. waterproofing;
8. crate;
9. provision of ventilation;
10. installation of drips;
11. cover installation.

Fixing the Mauerlat

In order for the roof to be securely fixed, care must be taken to securely connect it to the wall of the building. If a wooden house is being built, then the Mauerlat is not required - the upper crown of a bar or log acts as this element. In this case, fastening to the wall is carried out using special “floating” fasteners. They are sold ready-made, most often they are called sleds. This version of the roof device allows the entire structure to slightly shift when the walls shrink without damage and deformation.

"Sliding" mount wooden house

A similar situation arises with a frame house. In this case, the upper wall trim will be the Mauerlat. It is attached to the racks of the frame with a gash using corners, staples or nails.

Methods for attaching rafters to the harness in frame house

The construction of a roof made of brick, concrete blocks or concrete implies fastening through a Mauerlat. In this case, there are several ways.

There are four ways to put the Mauerlat on the wall:

• on staples;
• on studs;
• for anchor bolts.

Mauerlat can be fixed on brackets. In this case, lay in the masonry from the inside wooden bars. They should be located at a distance of 4 rows from the edge. One side of the bracket is attached to the Mauerlat, and the other to the same bar in the masonry. The method can also be classified as simple. It is not recommended for large buildings with high loads.

Mauerlat fastening on brackets. In the laying of the wall, antiseptic wooden bars are provided with a step of 1-1.5 m

Do-it-yourself fastening during roof installation can be carried out through studs or anchor bolts with a diameter of 10-12 mm. Fasteners are laid in the masonry. A Mauerlat is temporarily placed on the edge, you need to lightly hit it with a hammer. After that, recesses remain on the beam in the places of fasteners. On them you need to make holes for the studs. After that, the timber is put on the fasteners and the nuts are tightened. The method is ideal for walls made of lightweight concrete in the presence of a monolithic armo-belt.

Fastening rafters to Mauerlat

In houses made of brick or stone, it is more reasonable to carry out with the help of a rigid attachment of the rafters to the Mauerlat. In this case, you can use both layered and hanging systems. The design assumes two ways:

• with a notch;
• without notch.

In the first case, the rafters are hemmed with a slope so that they are tightly adjacent to the Mauerlat. For the removal of the cornice, fillies are provided. They are attached to the leg with an overlap of at least 1 m. Rigid fixation of the knot should be done using self-tapping screws, nails or staples. But the assembled frame will have greater reliability if metal corners with holes for self-tapping screws are used for fixing.

The method without cutting often does not involve the use of fillies. In this case, the frame overhang is provided by the beams themselves. This option is simpler than the previous one, since it does not require high accuracy. It is suitable for beginners. For a snug fit to the Mauerlat, in this case, use persistent bars or boards. Rigid fixation, as in the previous case, is performed with metal corners on both sides.

Fastening rafters to the wall

The frame made must be fixed to the box of the building - this will not allow a strong gust of wind to tear off the roof. To do this, it is necessary to take as a rule the use of a twist of two wires with a diameter of 4 mm. They are wrapped around the leg at the place of support on the Mauerlat, and after that the wire is attached to the wall on an anchor or ruff about 4-5 rows before the cut. The element must be laid in advance in masonry.

Windbreak protection

For wooden house can simplify the task. You can assemble the frame using staples. This option will speed up the process. But it is important to remember that this method is only suitable if the walls are made of wood.

System Gain

How to strengthen the frame with spans of more than 6 meters? It is necessary to reduce the free span of the rafters. For this, struts and racks are used. It is necessary to make reinforcement taking into account the layout, it is important that these elements do not interfere with the stay of people and harmoniously fit into the interior.

The struts are usually placed at an angle of 45 or 60 degrees to the horizontal plane. Racks cannot be supported on the floor span. They are allowed to be installed on the underlying walls or beams and trusses thrown between the walls.

Tightening is necessary to reduce thrust. Because of him, the rafters can simply disperse. This is especially true for systems with hanging beams. To assemble the frame, use two puffs, which are attached on both sides of the rafters. Fixation is carried out on self-tapping screws, nails or studs.

At the top, the rafters rest on an intermediate or ridge run. Depending on the chosen system, location and width of the span, it is made of timber with a cross section of 50x100 to 100x200 mm. Fastening is carried out on connecting metal plates, bolts or nails.

crate

Before starting work at this stage, it is required to lay a waterproofing material. Builders recommend using a vapor-diffusion moisture and wind-protective membrane. It is more expensive than plastic film, but provides better protection. Your home is not a reason to save money.

The roof requires fixing the crate. The type depends on the chosen roofing material. For metal, a sparse crate made of boards 32-40 mm thick will suffice. Under bituminous tiles, a solid crate of 25-32 mm boards or moisture-resistant plywood is needed.

Ventilation of the under-roof space

Before proceeding to the stage of laying the roof, it is worth considering the ventilation of the under-roof space. This will protect the structure from mold, fungus and destruction.

Proper arrangement of ventilation under the roof will protect the structure from the appearance of fungus

For ventilation it is necessary to provide:

• air flow through the eaves (the filing of the cornice is made with a rarefied board or special perforated spotlights);
• air movement under the coating (there should be a gap of 2-3 cm between the insulation and the roof);
• air outlet in the area of ​​\u200b\u200bthe ridge (for this, a ridge and / or point aerator is installed on the roof).

Roofing

The type of roofing is selected from aesthetic and economic considerations. It is also worth studying the offers of manufacturers and finding out the permissible slope. For example, bitumen shingles are not recommended for laying at a slope of more than 45 °.

Seam roofing is a lightweight, fireproof and durable coating.

The lining material must provide reliable waterproofing. Its installation is carried out in strict accordance with the manufacturer's instructions. There are five most common types of coverage: roof insulation.

Building a home is a complex and lengthy process. It contains many pitfalls that await the novice builder at every stage. The roof is an important part of any home. We will dwell on the types of roofs and roofing materials separately in another article. Today we will talk about how to make rafters on a gable (gable) roof, we will touch on the topic of calculation and selection of material.

Design features

The traditional option for Russia is a gable roof. Slopes are called flat parts of the roof, having a constant slope to the horizon. The angle of inclination must be accurately calculated, it can vary from 10-15 to 60-80 degrees. Failure to comply with the specified parameters leads to negative consequences:

• As the angle of inclination increases, the length of the rafters changes and, accordingly, the height of the roof. This, in turn, leads to an increase in the load on the frame of the house and fastenings. In addition, due to the high windage, the sharp roof is highly exposed to wind. In regions where powerful wind gusts prevail, such a structure can collapse and harm people's health.
• A roof with a slope of less than 10 degrees is also not recommended: the roof will not withstand the pressure of snow accumulating on its surface. In places with heavy rainfall, the optimal slope angle is 45-60 degrees.

Thus, the correct slope will ensure the gable roof durability and safety. The basis for calculating this indicator is the corresponding tables of wind and snow load for a particular region.

AT last years popularity for private housing construction is gaining a device called attic. Such a gable design allows you to organize a full-fledged living space of a large area and height in the under-roof space, as well as equip a spacious balcony from the side of one of the facades of the house.

At the same time, roof trusses for the attic structure are more complex and massive, require careful calculation and fastening.

Roof device: getting acquainted with the main elements

Structurally, a gable roof is represented by a rigid wooden frame, which is mainly made from coniferous lumber of a certain section. The specific size of the frame elements and the fastening step are calculated based on the dimensions of the house and the load on the roof.

The main components of a gable roof include:

Types of truss systems: choose the right one

Gable roofs according to the type of truss system are divided into layered and hanging. The former involve the installation of racks and a common bed attached to the Mauerlat, the latter are characterized by the presence of a puff between the base of the rafters.

Hanging rafters are used for small buildings without internal load-bearing walls, layered - for buildings with a load-bearing middle partition. The choice of truss system depends on the size of the house, the estimated angle of inclination of the slope and roofing materials, which together determine the amount of load on the entire structure. Only a professional builder can choose the right type of system and make an accurate calculation.

Roof parameters

Right before the start construction works, at the design stage, perform the calculation optimal parameters roofs: the angle of inclination of the slopes, the dimensions of the section, the frequency of the installation step and the layout of the rafters.

Wind and snow loads in different regions of our country are uneven. SNiP 2.01.07-85 will help calculate them for a specific area. At the same time, experts recommend making a certain margin of safety for the roof frame, taking into account possible peak loads.

In addition, there is still a constant force of influence on the truss system - the pressure of the roofing material. The table shows the weight of popular coatings per 1 m 2 of surface.

Various types of materials present and different requirements to the optimal slope angle. This aspect must also be taken into account when designing the roof.

Roof slope depending on the material

No less important is the calculation of the installation step and fastening of the rafters to the Mauerlat, that is, the distance between adjacent trusses. Usually this value is 0.6-1 m. A change in this indicator upwards leads to an increase in the load on the rafters and, as a result, an increase in their cross-sectional area. It is necessary to set the supports so that the fastening step is the same for all pairs.

The section of the rafters directly depends on the above indicators. By the way, the strength characteristics of wood of different species are different (laminated timber has the greatest strength). Here is a table for calculating the dimensions of the section for rafters from coniferous varieties, depending on the installation step and the length of the support.

Preparation and processing of lumber for the frame

Installation of the truss system is easy to perform, having at hand a drawing of the roof, the necessary materials and having experience with carpentry and carpentry tools.

When choosing wood for the roof frame, preference should be given to pre-dried boards without rot and with a minimum number of knots.

If desired, rafters, racks, mauerlat and other elements can be pre-cut. Treatment with antiseptic compounds and flame retardants in two layers is required.

Applying liquid mordants with a brush or roller is difficult and time consuming. It is much more efficient to use dipping. To do this, a trough is made from edged boards with a section of 200x25 and a length of 6 meters, inside which a plastic film is spread in one piece and fixed along the edges with a construction stapler.

Several antiseptic canisters are poured into the resulting container, the lumber is immersed in the solution and, thus, the treatment is carried out at a time. According to the instructions, it is forbidden to mix compounds with different actions to speed up the impregnation.

Assembly of roof trusses

Builders have no consensus on where to assemble trusses from rafters. Some make them on the ground and lift the finished structures up for installation, others prefer to do all the work on the site of the future roof. Both methods are acceptable. The first option is safer, the second option is less expensive, since a crane-manipulator is required to lift large-sized farms, which is associated with additional costs.

Regardless of the place of work, the first step is to prepare templates for sawing the ends of the parts at a certain angle or the required shape. Taking into account the specified parameters, measure the desired length of lumber and cut it with a carpentry saw or a circular saw.

Scheme of the truss system

The next rafter pair is attached taking into account the installation step. In order not to measure the required value each time, pieces of boards of a given length are prepared in advance and fixed to the Mauerlat between trusses. After installing all the rafters, the upper part of the supports is connected with a ridge run. To increase the strength of the structure, longitudinal bars are mounted on the sides.

This completes the installation of the rafters. It remains only to sheathe the trusses from the outside with a crate of unedged boards, bars or sheets of plywood and OSB, laying insulation and vapor barrier. Read more about this in other articles.