The rafter system of even a small private house has a rather complicated design and, accordingly, considerable weight. During the operation of the building, its roof has significant spacer loads on the walls. To prevent premature destruction of the box at home, roof rafters are usually installed on a solid basis. This design is the answer to the question of Mauerlat - what is it.
What lumber to choose
Roof bases are assembled for obvious reasons, of course, only from high-quality timber or boards. In any case, the lumber intended for the installation of the Mauerlat should be well-dried and even. It is also not allowed to use a beam with a large number of knots to assemble such structures.
The cross-section of lumber intended for the installation of roof bases depends on the construction of the latter, their size and even the climatic characteristics of the area in which the house is being built. In windy areas, roofs are connected to walls, usually using a sufficiently thick, solid hardwood beam. It can be, for example, oak, birch or aspen. Coniferous lumber is allowed to be used only for the construction of houses of small area in windless regions.
Most often, owners of suburban areas build houses with gable roofs on their land. Mauerlat sizes of such roofs are usually not too large. To assemble the bases of gable roofs, according to the norms of SNiP, it is supposed to use a bar with a cross section of not less than 10x10 cm. But most often the roof rafter system of such buildings is erected on a 10x15 cm thick Mauerlat.
Basic mounting methods
So, the answer to the question of Mauerlat - what is it, is the supporting structure of the roof of the house, connecting the rafter system with the walls. There are several ways of actually installing the base of the roof of the building.
When a Mauerlat is being assembled, a timber can be crammed on top of the walls of a house’s box either only on two opposite long walls or around the entire perimeter. In this case, it all depends on the design features of the rafter system. In any case, the fixed base of the roof of the house should be very reliable.
Mauerlat can be fixed on the walls of the house using:
- anchor bolts;
- wire;
- wire and staples.
How to bolt
This technology of fixing Mauerlat is usually used on concrete walls. Also, anchor bolts of the roof base are attached to gas and foam concrete boxes with an armored belt. Such a technique for fixing the timber looks like this:
- during the pouring of walls or armored belts, anchor bolts are poured into concrete;
- marking is performed on the Mauerlat beam;
- holes for bolts are drilled on the marking.
In the future, the beam is simply put on the rods of the fasteners poured into the concrete and fixed with nuts with gaskets.
Wire Mauerlatt
This method of fixation is used for laying timber on brick walls. The wire for mounting the Mauerlat using this technology is used quite thick. At the same time, it is also supposed to be folded several times.
The technology of attaching the Mauerlat to the wire looks as follows:
- wire is laid into the masonry at the level of 4 rows from above;
- after the fastening solution has dried, a timber is laid on top of the wall;
- the ends of the wire are bent up;
- the wire twists tightly over the Mauerlat.
Bracket Mount
The answer to the question of what Mauerlat is - what kind of structure it is, is a thick beam laid on the walls of the building as a support under the rafters. Fixing such structures on the boxes of buildings is actually a very responsible matter. After all, the roof service life in the future will depend on how well the Mauerlat is laid.
Fixing the Mauerlat to the wall with wire is a pretty reliable method. A similar technique for fixing the beam on the boxes is actually used quite often. However, for buildings of a large area with a heavy roof, the use of such fasteners may be insufficient. When mounting the bases of large roofs in combination with wire, brackets are often used.
These elements are also built into the masonry during the construction of the box at the level of 4-5 rows. When installing the beam on the wall, the free part of the bracket is simply driven into its thickness.
Fastener Installation Step
In order for the Mauerlat to subsequently perform its functions effectively, it is supposed to fix it on the walls using a rather large number of fasteners. The installation step of the latter depends on the roof structure, its weight, etc. On the gable roofs that are most popular with owners of suburban areas, bolts or wire when assembling Mauerlats are mounted in walls with an interval of about 80-100 cm.
How to fix the Mauerlat: joining the beam in the corners
Around the perimeter of the box, the base for the roof truss system of the house is installed quite often. When using a Mauerlat of this design, the beam, among other things, has to be connected in the corners. Since Mauerlat is a very important element of the rafter system, of course, this procedure should be performed correctly.
The beam is fastened in the corners when assembling the base of the roof of the house most often by the "half-tree" method. Previously, anchors are necessarily poured into the corners or the wire is embedded. At the junction fixed to the wall, the beam must be mandatory.
Sawmills most often sell 6000 mm timber in the market. The walls of country houses are often long. Therefore, it is usually necessary to collect the Mauerlat for the roof with building. Separate bars on the wall are joined according to the same technology as in the corners. That is, they are connected using the “half-tree” method with fastening with a fixed anchor bolt or wire.
Both in the corners and along the length of the Mauerlat at the joints before installing the rafters, it is advisable to additionally fasten them with nails or steel plates.
Waterproofing
As you know, wood, even the highest quality, is very afraid of moisture. Therefore, Mauerlat should only be installed on top of a waterproofing pad laid on the wall. Most often, under the base of the roof of the house, an ordinary ruberoid is laid. Attach it in most cases to bitumen mastic. To equip the highest quality waterproofing, at least two layers of roofing material are laid on top of the wall.
Installation procedure
Before you start laying the beam, the top of the walls must be cleaned of dust and debris. Further:
- lay a waterproofing insulator around the box;
- those bars which will subsequently be located in the corners and in the place of joints are cut accordingly;
- lay the beam on the walls of the box and mount them in the selected way.
Lumber pre-designed for Mauerlat installation is necessarily treated with antiseptic and water-repellent agents.
Arrangement of armopoyas under Mauerlat
Pour such a design around the perimeter of foam concrete boxes as follows:
- on the top of each wall mount the formwork from the boards with bolting through the planks;
- install a reinforcing cage inside the formwork;
- sheets of expanded polystyrene for insulation are installed in the assembled form along the inner edge (from the side of the room);
- fill the form with cement mortar.
It is possible to start mounting the Mauerlat and the rafter system on the belt no earlier than 28 days after pouring it. You can’t start building a roof before. Unripe concrete of the weight of the roof truss system may simply not be able to withstand.
Installation of rafters
Thus, the answer to the question of Mauerlat - what is it, is understandable. In the roof structure, this element serves as a support for the rafters. In order for the roof to subsequently turn out to be reliable, to fix the supports of its frame to the Mauerlat, of course, it should also be done correctly.
Installing the rafters is laid over the anchor bolts of the very base of the roof. In this case, the fixing of the rafters to the Mauerlat itself can also be done in several ways. Fasten these elements usually using:
- corners;
- special elements with a moving part, called "skids";
- nails.
Most often, the rafters to the Mauerlat are mounted using galvanized corners. This method is considered the simplest and fastest to execute. Before mounting by means of corners in each rafter leg, a landing nest is preliminarily cut using a template.
Nails for fixing these elements of the roof frame on the Mauerlat are also used quite often. Such fasteners simply clog into the thickness of the timber of the base of the roof through all the planes of the rafters. For reliability with this method of fixation, thick wire is additionally used.
In wooden houses, the role of the Mauerlat is performed either by the upper binding, or by the crown. A feature of buildings built from logs or beams is that they are able to shrink. Therefore, in this case, the rafters are not rigidly attached to the box. To fix these elements on wooden walls, a “slide” is used. When shrinking, the movable part of such fasteners simply extends, which avoids deformation of the roof frame.