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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. The 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.
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.
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). Holes are then made in the board in the necessary places, into 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.
Installation of rafters
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
- Extreme trusses are exposed, forming gables. They are aligned and fixed with temporary stops. You may also need a temporary mount nailed to the wall of the house: they nail a board that sticks out above the walls. You can level the first truss along it (unless, of course, the wall is flat). Lined on the other side with temporary struts, it will not go anywhere.
How to correctly set the truss system - Further, twine is pulled between the installed extreme farms. It runs at the level of the ridge and on both sides below – at the end of the rafter legs. The stretched twine is checked for horizontality – a good building level is applied. If there are deviations, and the trusses are set strictly vertically, you will have to file the rafter legs on one of them. Sometimes, with a deviation on the ridge cord, they try to correct the deviation by tilting the truss. But this cannot be done: the whole system will “float”.
A twine is pulled between the exposed extreme trusses to check the correct geometry - The exposed extreme farms are fixed to the Mauerlat. Mounting methods depend on the type of system chosen and may or may not be sliding. Types of truss systems for gable roofs and attachment points for rafter legs to Mauerlat and ridge beam outlined in this article.
- The following farms are placed, focusing on the stretched twine. It is more convenient to pre-mark the required installation step of the rafters on the Mauerlat, check whether the markings are correctly applied, and only then proceed to lifting and arranging the trusses. In order not to knock down the installed rafters during the construction process, they are attached to one another with temporary beams, spacers and slopes are placed. They are removed after the crate is stuffed.
- The exposed truss system is covered with a layer of waterproofing membrane, over which the crate is stuffed. The membrane on insulated roofs according to the latest technologies is mandatory, otherwise the insulation will get wet, which will lead to its inefficiency (simply thrown away money). If the roof is cold, you can do without waterproofing.
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 beam, 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 helpful.
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 a frame house, but when installed on buildings of a different type (except for wooden houses), there is no difference.