Roof, of course, is one of the most important structural elements of any building, including low-rise private. When building a country house, a variety of types of roofs can be mounted. But most often, gable structures of this type are still being built on one-story buildings. Such roofs, in turn, can be simple or broken. Installation schemes for gable roof truss systems of various configurations will be discussed by us below in the article.
What is
Gable roofs have an extremely simple design. That is why they are very popular with private developers. Simple roofs of this type consist, as can be judged by their name, of two slopes. At the same time, the latter have the shape of a rectangle and are located in the roof structure at a certain angle. The scheme of the truss system of a gable roof of this variety is presented below.
Mansard broken roofs have a slightly more complex configuration. Their constructiona little different. There are also two slopes for such roofs. But a feature of such roofs is the presence of a break. Each of the slopes of such a roof consists of two rectangular parts located at an angle. A diagram of the truss system of a gable roof attic can be seen below.
Building broken roofs on country houses, of course, is more difficult than simple ones. But at the same time, such roofs are more convenient to use. The attic under such roofs has a very large volume. And on it, if desired, you can even equip one more additional living space.
Next, we present to the reader's attention, for clarity, also a photo of the gable roof truss system. As you can see, the design of such roofs is actually relatively simple.
The main elements of the truss system
When assembling the frame of both conventional and broken gable roofs, in most cases the following elements are mounted:
- Mauerlat;
- rafter legs;
- sheathing.
Sometimes a ridge board is included in the design of roofs of this variety. Also, in some cases, when assembling gable roof frames, racks, girders, puffs and struts can be installed. Such elements are usually used when installing roofs of large-area houses.
In the scheme of the truss system of a gable roof with a bay window, if the latter is located on the side of the building, among other things, elements such as valleys are included. Roofs of this type already have a rather complex configuration. In any case, it is probably not worth it for a beginner to take on the construction of such a roof. At the very least, it is better to entrust the development of a roof project for a building with a bay window to a specialist.
Selection of materials
About how to make a gable roof truss system with your own hands, let's talk a little lower. To begin with, let's figure out what materials will be required for the construction of such a structure. In some cases, the gable roof truss system can be assembled from metal elements. However, such materials for the installation of roofs are usually used only in the construction of various kinds of industrial buildings or small architectural forms.
Roofs of private houses in the vast majority of cases are assembled from boards and timber. The advantages of such structures include, first of all, low cost and ease of installation.
Of course, timber for gable roofs should be chosen correctly. For the manufacture of rafters, in most cases, a board with a section of 100x150 mm is used. Mauerlat is most often assembled from timber 150x150 mm or 200x200 mm.
For the installation of the crate, a board with a width of no more than 15 cm is usually used. Over time, over time, under the influence of adverse weather factors, a larger material may warp. And this, in turn, will lead to damage to the roof sheathing.
In any case, lumber for the installation of a gable roof truss system should be of high quality - 1-3 grades. Otherwise, the roof of the building will not last too long in the future. Thatthere is a beam and a board with a small number of knots to use for the construction of the roof. Also, such material must be necessarily well dried. Otherwise, after a couple of years, the roof structures will warp, dry out and crack. As a result, the roof will have to be repaired or even completely replaced with a new truss system.
Buy for the assembly of the roof should be lumber with a moisture content of not more than 12-15%. And even such boards and beams should be dried for several months in a shaded place before starting work.
Almost any type of wood can be used for assembling roofs. In the construction of low-rise private houses, cheap pine is most often used for this purpose. Experienced craftsmen do not advise choosing such boards longer than 6 m for gable roof rafters. For Mauerlat, it is still recommended to use hardwood timber. That is, you should not purchase soft pine for mounting this structural element of the gable roof frame.
Self-development of the scheme of the gable roof truss system
Before you start building the roof of a country house, of course, you should make all the necessary calculations and draw up a project. The development of a drawing of such a design will make it possible to avoid various kinds of errors and unnecessary waste of material during its assembly. When drawing up a roof project, first of all, you need to decide on the angle of inclination of its slopes. The choice of this indicator for gable roofs depends on what wind and snow load they will be subjected to inoperation.
In regions with a large amount of average annual precipitation, in most cases rather steep roofs are erected. The slopes of such roofs are located at a significant angle. Snow from such roofs quickly slides off and exerts almost no load on them.
In windy regions, flat gable roofs are usually erected. Such roofs practically do not sail. And accordingly, in a windy region, they can last a long time. The angle of inclination of the slopes of such roofs can be made quite small. However, it should not be less than 5 degrees.
Calculate the angle of inclination of the roof slopes, taking into account the indicators of the wind and snow load tables. Almost throughout Russia, the optimal parameter for installing roof rafters is 30-45 degrees. This is how most owners of country houses build roofs.
After all calculations are completed, a diagram of the gable roof truss system is drawn. When compiling such a drawing, according to the regulations, it is supposed to indicate the length and cross section of all elements, as well as note the ways of pairing nodes.
Installation of Mauerlat
Next, let's look at how the gable roof truss system is assembled with your own hands step by step. First of all, when installing the frame of such roofs, of course, a Mauerlat is installed. This structural element of the roof truss system is its support and carries the main load from it. The Mauerlat is laid on the walls of the box of the building under construction from above. Fasten thiselement in most cases on anchor bolts. Such fasteners are immured in advance in the masonry of the walls or in the concrete of the upper reinforcing belt.
Mauerlat is not used only in the construction of cobbled and log houses. In such buildings, its role is played by the upper crown.
When erecting large-area truss systems, Mauerlat elements are usually mounted on all four walls. On such buildings, roofs with a ridge are most often erected. And on the end facades, the Mauerlat serves as a support for the central gable posts.
When building roofs of small one-story buildings, the support beam is usually laid only on two parallel long walls of the box. In this case, the Mauerlat will only take the load from the rafters themselves.
It often happens that the beam chosen for the assembly of the roof frame support frame has a smaller width than the walls. In this case, the Mauerlat is usually mounted closer to the outer edge of the latter. Before installing this element, the top of the walls must be laid with two layers of roofing material.
Rafters
Such elements serve as a support for the insulating "pie" and sheathing in the design of the gable roof truss system. In their manufacture, it is important to maintain the correct dimensions and geometry. Otherwise, the roof will subsequently turn out to be sloppy and will not effectively protect the interior of the house from adverse weather factors.
Cutting rafters when building gable roofs is supposed to be done using a template. It is possible to make such a devicefor example, from some junk board. The length of the rafters of a gable roof is calculated quite simply. To do this, use the formula for a right triangle, in which:
- half the width of the building is equal to the length of the leg;
- the height of the skating rack is equal to the length of the second leg.
The length of the rafters themselves in this case will be calculated as the length of the hypotenuse through the sine or cosine of the slope angle.
Rafters are placed when erecting a gable roof frame, usually with a step of 80 cm. This is the width of standard mineral wool slabs. With this arrangement, it will be possible to mount this insulator in the future, respectively, without cutting. Standard purchased attic windows usually have a width of 80 cm.
Step-by-step technology for mounting a truss system without a ridge
Such frames are equipped with the self-construction of suburban residential buildings most often. They are called a hanging truss system. Gable roofs of this type are extremely easy to install and at the same time are considered reliable.
At rafters when cutting in this case most often:
- a socket is cut out at one end for landing on a Mauerlat;
- the second end is cut off depending on the slope angle.
The rafters cut according to the template are usually mounted using this technology:
- install two end trusses over both end facades of the house;
- stretch rope between farms;
- focusing on the cord, mount intermediate trusses.
Such connections should be as reliable as possible.
The rafters can be attached to the Mauerlat when installing the gable roof frame in several ways. Most often, these elements are fixed on the support beam using galvanized corners. But in some cases, the rafters can also be fixed with a knot of three nails. At the top, the rafters are interconnected using galvanized steel plates.
Assembling the frame with the ridge
Hanging gable roof truss systems can be quite strong and durable. But when building large roofs, more reliable structures with a ridge are often assembled. Such roofs are also mounted using a fairly simple technology. In this case, two end support posts are installed first. Next, a cord is stretched between them. Then intermediate racks are mounted. They rest on pre-laid floor beams.
At the next stage, a ridge board is attached to the racks installed in this way. Then the rafters are cut and installed. The supporting elements of the frame are mounted in this case, also usually in increments of 80 cm. They are attached to the ridge using corners. Sometimes the rafters are also brought out above this central board and fastened with steel plates. Often, under the ridge, the legs are additionally fixed withusing horizontal boards - crossbars.
One of the elements of the truss system of gable roofs of houses can be struts. They are placed at a certain angle between the uprights and the rafters. Such elements give rigidity to the roof frame.
Features of mounting rafters on the roofs of wooden houses
The rafters are installed on such buildings using the same technology as on brick, block or concrete ones. However, they are attached to the upper crown using not corners or nails, but special elements called sleds.
A feature of block and log buildings is that they shrink over time. With a rigid attachment of the rafters to the Mauerlat, because of this, the roof frame can subsequently be severely warped. The use of sleds avoids this problem. These fasteners, unlike the corners, have a movable part. Thanks to this, the rafters simply take the right position when the box shrinks.
Installation of a broken roof
The truss system of a gable roof with an attic is being built, of course, using a more sophisticated technology. However, it will most likely be possible to assemble such a frame with your own hands. When installing the truss systems of such roofs, a Mauerlat is also preliminarily laid on the walls of the house. In this case, it is best to mount it closer to the inner edge of the walls. Floor beams in such a roof are usually taken out of the box in accordance with the angle of the rafters.
Further work is carried out in the followingOK:
- extreme end posts are mounted (two on each side);
- intermediate racks are installed along the reference cord;
- racks are connected by girders (from the side of the long walls of the building);
- puffs are mounted between paired racks;
- layered (lower) rafters are installed with fastening to the racks and removal of the beams;
- on puffs, simultaneously performing the function of attic ceiling beams, racks under the ridge are mounted using a guide cord;
- the ridge board itself is installed;
- hanging rafters are mounted.
Using this technology, you end up with a durable gable roof truss system. Sheathing it in the future can be any roofing material.
When assembling a broken gable roof, the rafters are fixed to the supporting elements, usually using steel plates. In roofs of this type, layered legs are often additionally strengthened using struts. The lower edge of these elements are fixed to the racks. In this case, the rafter system of a gable mansard roof is as reliable as possible. Struts are usually used when installing large roof frames.
Crate stuffing
The gable roof truss system is quite simple. One of its mandatory elements is, of course, the crate. The installation technology of this roof element depends primarily onhow in the future the owners of the house want to see the attic - cold or residential. In the first case, the crate is stuffed onto the rafters immediately after they are installed. If the attic or attic is supposed to be made residential, first the waterproofing and insulation are installed.
In this case, the work is done in the following order:
- between the rafters from the side of the future attic, a rare "mesh" of wire is attached to create a support for insulation;
- mineral wool slabs are placed between the rafters;
- on top of the insulator with fastening on bars 3 cm thick, a plastic film is mounted with a slight sag (no more than 2 cm);
- the crate itself is stuffed onto the bars.
The crate can be mounted on the rafters with different steps. The choice of this parameter depends on the type of roofing material used for roof sheathing. For example, when using a metal tile, the step between the purlins will depend on the distance between the waves of the sheets.
In any case, the boards under the cladding should, of course, be fixed at the same distance from each other. At the top of the slopes, at the ridge, two rows of battens are usually laid out end-to-end. The boards are also attached to the bottom edge of the rafters.
Solid crate
On gable roofs, in most cases, it is a sparse crate that is mounted. But sometimes, when assembling such roofs, it has to be made solid. This is done, for example, if they want to cover the roof with roofing felt or flexible tiles. The basic scheme of the gable roof truss system in this case will be the same. But instead of a board on such roofs, some kind of sheet material is used to assemble the crate. Most often in our time, inexpensive OSB is used for this purpose.
In some cases, such sheets are attached directly to the rafters or to the bars holding the waterproofing. But more often, a rough crate from the board is still stuffed under the OSB.
Mistakes to Avoid
Simplicity of design is one of the features of the gable roof truss system. How to assemble the roof of this variety, we found out. They take up the construction of roofs of this type very often, including people who do not have much experience in installing roof systems. At the same time, beginners often make mistakes, the result of which in the future is a reduction in the life of the roof. When building even simple gable roofs, of course, you need to follow all the required technologies exactly.
The most common beginner mistakes when assembling such structures are:
- Inflated spacing between rafters. In no case can you save on material when building a roof frame. As already mentioned, most often the rafters are usually installed at a distance of 80 cm from each other. However, such a step is permissible only if sufficiently thick lumber is used under the roof supports. Accurate calculations of the required distance between the rafters can be determined depending on their section using special tables.
- Unreliablemauerlat mount. The installation step of the anchors for the rafters of the truss system should be a maximum of 65-80 cm. If this condition is not met, the roof of the house can simply be torn off during a hurricane.
- Lack of insulator between the frame elements and the chimney. The device of the gable roof truss system, according to the SNiP standards, must be such that the walls of the latter are located no closer than 25 cm to the wooden frame elements. At the same time, the pipe at the point of passage through the ceiling and the slope is supposed to be wrapped with a layer of mineral wool with a thickness of at least 5 cm. Failure to comply with this condition can lead not only to a reduction in the life of the roof, but also to the loss of the house itself as a result of a fire.
Rafters, as already mentioned, are usually attached to the Mauerlat using steel corners. Such elements can be fixed on wood using screws. So that the fasteners of this variety do not loosen in the future, the holes for them should be drilled with a slightly smaller diameter than their core.
Rules for the arrangement of a residential attic
Thus, above we examined how to assemble a gable roof truss system with our own hands step by step and in all details. After the crate of such a roof is assembled, the actual installation of the roofing material begins. For finishing gable roofs, both slate or ondulin, and metal tiles or flexible sheets can be used. The laying technology in any case will depend onon the type of material chosen. Metal tiles, for example, are attached to the structures of the truss system using roofing screws, roofing material is fixed on bituminous mastic, etc.
After sheathing the roof, you can proceed to the arrangement of the attic. In ordinary gable roofs, in most cases it is left cold and later used to dry, for example, onions, garlic, chopped fruits, berries for winter storage or storage of things that have served their purpose.
The scheme of the truss system of a gable roof with an attic is more complex. Roofs of this type are usually more expensive. But at the same time, under such roofs it is easy to equip a fairly spacious and comfortable living space. In this case, the roof slopes from the inside are first covered with a vapor barrier. The use of such material for attics is mandatory. The air inside the house is usually warmer than outside. Because of this, a large amount of condensate can accumulate on the attic structures of a residential building. Without a vapor barrier, mineral wool will quickly get wet and stop working.
At the final stage, when arranging the attic, the slopes are sheathed, for example, with OSB. Then they simply get off with some kind of finishing material - they are pasted over with wallpaper, upholstered with clapboard, decorative plywood, drywall, etc.
