BUILDING THE ROOF OF THE HOUSE OWN HANDS. Chapter II

CONSTRUCTION OF A RAIL SYSTEM

For an example, we will consider step-by-step instructions for one of the most complex roofs - a four-pitched roof. Understanding the construction technology of this rafter system, it will not be difficult to understand the technology and assemble simpler single-slope or gable ones on your own. Step 1. Take two long boards, with their help it is easier to determine the length of the rafter legs, the angle of inclination of the slopes and the height of the roof. Fix the boards temporarily to a vertical support on the wall of the house. Raise or lower them until you find an acceptable position. If the size of the house allows, then it is better to design the rafter system so that the length of the legs does not exceed 6 m. Such lumber can be bought, there will be no need to build up. The extension not only takes a lot of time, but also weakens the structure, requires the installation of additional supports. Step 2. Fill the reinforcing belt. It not only increases the height of the attic space, but also makes it possible to extend the overhang of the rafter legs and additionally protect the facade walls from atmospheric precipitation. The width of the belt should be at least 30 cm, the height depending on the size of the house. How to fill in a reinforcing belt? -Drill holes 15–20 cm long in the walls, insert metal rods 12–15 mm in diameter into them. There must be a thread at the top. If it is difficult to find such elements in the implementation, then you can weld threaded studs to ordinary building fittings. The distance between the anchors is approximately 1 m. -Set the formwork around the perimeter of the house. To do this, use edged boards 20 × 150 mm, so that they are not bursting with concrete after 1.5–2.0 m, fix them with pegs. Do not be afraid that the reinforcing belt will not have a perfectly even width along the entire length, this element closes when the roof is built further.

-Prepare the concrete. The solution must be made strong, one part of the cement should be given a part of sand and two parts of crushed stone. You can cook it manually directly on the floor slabs of the house or on the ground with a concrete mixer, and then manually feed the mass upstairs. - Lay the reinforcement in the formwork, one bar is sufficient around the perimeter. Be sure to lift the bar at least 5 cm above the floor surface. It should not lie in the middle of the belt, in this position the reinforcement does not work. Any piece of wood or pieces of concrete blocks can be used as linings. -Fill the belt with concrete, work carefully, strictly maintain the horizontal position of the upper plane. Use an ordinary level to check.

Allow at least three days for concrete to harden. Remember that it will gain 50% of its strength only after two weeks, only then can the structure be fully loaded. If the weather is very warm and windy, then the concrete belt should be watered with plenty of water at least twice a day. Concrete gains strength not during drying, but during the favorable course of chemical reactions; moisture is constantly required for this.

The construction of the rafter system conventionally consists of four stages: the installation of the Mauerlat, the installation of the skate beam, the installation of the rafters (hip and diagonal) and the arrangement of the lathing.

INSTALLING MAUERLAT

Work begins after the concrete of the reinforcing belt has gained sufficient strength and the formwork is dismantled. For the Mauerlat, a bar of 200 × 100 mm is used. This is a very important element of the rafter system, it serves to support the rafter legs and evenly distribute point loads over the entire area of ​​the facade walls. Step 1. Place the timber next to the reinforcing belt, accurately mark the exit points of the anchors. It's easier to do this without a tape measure. Turn it over, narrow side down and place it on your belt, mark the position of the anchors with a pencil. Then transfer the marks to the wide side of the beam, in these places you need to drill holes.

Step 2. Drill holes, hold the drill bit as vertically as possible, and avoid distortions. The work should be done by an experienced carpenter. A beginner can spoil the beam, it is necessary to displace all holes by reducing its length. Step 3. Prepare strips of waterproofing under the Mauerlat, it is better to buy an ordinary cheap roofing material. The strip is cut from the roll, no need to roll it. The material is perfectly cut with a grinder with a disc for metal. Step 4. Spread the waterproofing strips on the reinforcement belt. Making holes is much easier with a hammer. Put the roofing material on the anchors and carefully punch holes for the studs in the waterproofing with a hammer. Only this must be done carefully, you cannot hit hard. Otherwise, there are risks of damaging the upper threads of the thread, while tightening the nuts, problems will arise. If you are afraid, then before laying the roofing material, screw the nuts on all the pins, after unscrewing they will automatically align the damaged turns.

Step 5. Install the beam on the anchors and tighten with nuts. Be sure to place large washers under them. If the Mauerlat fits tightly on the studs, then you have to hammer with a sledgehammer. This situation indicates a lack of qualifications for roofers.

It is better to make Mauerlat from pine, and not from spruce, there is much more resin in it, respectively, it is not damaged by putrefactive diseases longer. How to distinguish pine from other conifers? For several reasons. First, the tree smells like resin and turpentine. The second - the pine has a bright yellow tint, large and lively knots. The third - the presence of black spots on lumber from pine indicates a high resin content, it acquires such a color after oxidation in air. Spruce is whiter, lighter in weight, few knots and has an unpleasant smell of cat feces. At the corners and along the length, the bars are connected in half a tree, it is advisable to fix these places with long nails or self-tapping screws made of stainless alloys.