The cost of erecting a roof is 25-35% of the cost of building the entire house, and the cost of works is 50-80% of the price of materials, so if the roof is built by own hands, then the savings can be 15% of the total estimate.
Mansard called any roof, under which there are rooms that are suitable for housing( mansard, or attic floor).
The attic roof is a complex and painstaking work.
In industrial construction, the installation of the roof is performed when the drawings show each assembly, fastening parts and the parts themselves with the dimensions taken out.
Builders do not think about the device of the roof, whether the load is properly designed, their task is to build a frame, cutting out the parts templates and fastening them together, while the roof fixing system is also indicated.
To understand how to make a roof skylight, you will have to study the video, photos and learn the theoretical part.
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Contents:
- Attic roof structure
- Preparatory work
- Frame collection order
Marsh roof structure
Comfortable ceiling height for living space from 2.5 m and above. The walls of the attic floor are often the roof slopes, so it is necessary to ensure their thermal insulation.
The top of the attic roof is a skate, a beam that lies parallel to the floor plane of the house, and is the highest point of the roof. Ribs of the roof are called rafters.
Ridge( upper) rafters descend from the ridge. Beams overlap joins the base of the left and right ridge roof rafters of the same roof section.
Racks( beams cross-section 100x100) are fixed on the interfloor overlap at a right angle at a distance of 0.8-1.5 meters from the outer wall.
The higher the racks and the closer they are to the walls of the house, the larger the living space of the attic.
Lateral( lower) rafters go from the attachment of the attic to Mauerlat. Each section of the attic roof consists of two ridge rafters and two side rails on each side.
The system of the same rafters forms a skate-ridge or lateral.
The most used variant of a mansard roof is a broken gable roof. In this case, the ridge and side rafters form an obtuse angle at the junction points.
If they lie on one straight line, then outwardly it looks like a classic gable roof.
When calculating the slope of the ramp, the materials of the future roof and climatic conditions are taken into account, it can be from 15 to 45 degrees. The more the slope, the less snow will linger.
In the low-snow regions, the broken roof of the house can be quite flat.
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In areas with strong winds, the ramp is recommended to be quite flat and provide additional reinforcement of the rafters from high wind load.
The standard slope of the skates is 30-35 degrees.
Preparatory work
The roof of the attic type is planned even before laying the floor between the first and the attic floor.
If you use wooden beams as an overlap, you need to provide a section of the beam and the distance between the beams so that they withstand the permissible load for the residential second floor.
These are usually beams of cross-section from 150 cm and above at a length of 6 m. Such beams are located at a distance of 80-90 cm from each other.
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The system is such that the longer the beam, the greater the load it will experience in the middle. The pressure will create the floor itself of the attic floor, furniture and, in fact, tenants.
Even if the attic is planned underneath the restrooms without furniture, floor joists with a cross section of less than 120 cm, laid with a distance of 100 cm from each other, are undesirable.
A robust device will ensure that the materials selected for the roof are correctly selected.
The heavier the roofing materials, and the longer the frame of the broken roof, the larger the cross-section is needed for the timber from which the frame can be built.
Usually cross-sections 60х120, 60х100 cm are used.
On many photos there is no device of a reinforcing belt on external bearing walls when the broken roof is planned.
The weight distribution system is such that the entire weight of the roof rests on the joists, and they, in turn, carry this and their weight to the walls.
The gable roof of a single-storey structure is much lighter than a broken mansard, so quite enough mauerlat( wooden lining on the perimeter of the walls below the beams of the floor).
If the walls of the timber or brick, then the Mauerlat cope with the fact that the attic roof device was reliable. It is important during the construction phase of the walls to provide a device for fixing the Mauerlat.
The system must be reliable. In the case where a hollow cinder block or a porous foam concrete is used as a material for walls, it is difficult to secure the mounting of the Mauerlate to the wall.
A successful reinforcement concrete belt, in which, during the leveling process, rods are installed to install the Mauerlat.
It is placed on a substrate of roofing material or other insulating material and aligned along the inner edge of the wall.
Before fixing, make sure that the beams forming the Mauerlat lie strictly parallel. Even a deviation of 2-3 cm will lead to deflection of the ramp.
If the house is up to 6 meters wide( the maximum permissible size of an unsupported inter-storey beams), then the beams overlap with both edges rest on the Mauerlat.
If the width of the house is more than 6 meters and the house has load-bearing walls perpendicular to the floor slabs, then the ceilings are installed according to the following system: one edge of the timber is fixed to the Mauerlat and the second to the inner supporting wall, on which the Mauerlat is already installed.
In continuation of this line the next beam from the inner wall to the opposite outer mauerlat is laid. The gap between the beams should be no less than 3-4 cm.
If the preliminary work is done correctly, then you have a completely finished overlap between the first and the attic floors. Now it's time to draw a future skeleton.
Study the theory with a photo of a broken roof and a video on which the attic roof is filmed.
Draw the house from the front side, the racks on the left and right, take out the rafters and count the angles of inclination. To change the slope of the ramp, increase or decrease the height of the racks.
Calculate the length of the rafters( the cosine of the slope, multiplied by the distance from the rack to the projection of the ridge - for the ridge slope, and the cosine of the slope angle of the side ramp, multiplied by the distance from the mauerlate to the post - for the side rafters).
Watch the video of the various ways of fixing the beams together. A qualitative fastening will provide a reliable frame.
If the climatic conditions excessively overload the high broken roof with winds, and the width of the house does not allow to allocate a lot of space for unused space behind the racks, it is possible to reduce the height of the racks and after the construction is completed, the installation of built-in cabinets along the entire perimeter of the side walls of the attic.
Procedure for assembling the frame
Make the roof frame only from high-quality wood. The main sign of a "dead" tree is a dark color.
If you can not buy dried wood in the drying chamber, then get a wet, but still at the stage of construction of the walls.
You can not use a fresh tree for a frame - under the influence of loads it will lose its shape and bend.
The raw timber can be dried naturally in one and a half to two months.
For this, we spread it clearly on the level with the distance between the beams up to 5 cm. No two bars should touch. After every 75-100 cm, the beam should rest on a flat surface.
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As support points, you can use a cinder block, laid out on a flat surface, but in no case should you use another bar, designed for the frame.
In the sunny and warm weather, the beams dry naturally, and in rainy weather they need to be covered. The construction of the frame is allowed only from completely dried wood.
Begin the installation, making sure that the racks and rafters are selected with straight wooden beams and that they do not have cracks and knots.
Saw-cut wood blanks of the same type should be treated with a fire-fighting agent and a mixture that prevents the formation of fungus.
Treatment should be performed twice with an interval of 1-2 days. Installation can begin when the wood has dried after treatment.
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How to assemble the frame in steps:
- Installation of racks. On top of the beams overlapping we lay without fixing 5-6 boards, 5 cm thick. They form a floor on which you can safely move. The same size bars are installed on the overlapping level. First put extreme. It is necessary to make sure that the opposite distances between the racks are equal. Then a cord stretches between the end rails. It performs a function of the level at which all others are exposed. From above on the racks put and fixed strapping. Now we have a rectangle in which all the other supports are mounted. To reduce the precariousness of the structure of the rack, it is necessary to straighten it with jigs to the beams of the floor. It is the racks - the weakest place in the frame system, so we will pay special attention to fixing them. The rack with the floor beam must be fixed with the help of a construction bracket of size 12-14.When all the racks are installed, incline them with overlapping with a bar of 50-60 cm section. It is worthwhile additionally attaching them to the outside with each other using an unedged board;
- Mounting of upper ramps( gable roof).At the top of the rafters are fastened together by staples. The ridge rafter rests on the strapping of the racks and is fixed to the beam of the attic floor. Installation of the upper triangle of the attic must be done only on the ground and lift the fully finished structure. The triangle is placed on the posts and attached to them by staples. Just as the installation of the second triangle is completed, it is necessary to connect them in several places among themselves. When all the designs are exposed, they can be fixed with a crate;
- At the top of each side rafter saw groove depth of 3-4 cm, it is wound straps. The angle of the groove is equal to the slope angle of the ramp. At the bottom of the side rafter is also made a groove to install it on the Mauerlat. Due to these two grooves rafters unloaded can stand without fixation. Prior to the application of the load that the crate will carry, it is necessary to fix the side rafter with the clamp to the strapping and to the mauerlat. Additional fixing should be done with self-tapping screws, swiveled at the fastening points of the rafters, at an angle;
- Rim - edged or unedged board or OSB slab - fixed to rafters using self-tapping screws. The edges of the skates should be even. The distance between the components of the lath depends on the roof. For slate, a distance of 3-4 cm is allowed, and for bituminous shingles a continuous crate is required;
- It remains to build the gables and to heat the skates and the broken roof skylight is ready.
In the process of implementing each step, take photos and videos. This will help to understand the errors in the event that the result you obtained does not satisfy you.
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For work you will need tools:
- hammers of different sizes;
- screwdriver;
- circular saw;
- pliers and small joinery tools.
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Also required consumables:
- staples size 12 or 14;
- wood screws 45-50 cm in length for the crate and 150 in length for additional fixing of the rafters;
- a hydrobarrier;
- construction stapler;
- as an insurance - belt installer.
It is better to call for help 2-3 assistants( you can actually cut it yourself on the ground, but you can not build the structures at a height alone).
The above system allows you to calculate the frame and make installation of the attic even without the experience and special knowledge. Mansard roof with their own hands is mounted easily for 2-3 weeks.
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