Building an attic is one of the most successful and low-cost ways to increase living space in a house. Thinking about how to make a mansard roof with your own hands, you need to immediately tune in to the fact that the process is quite laborious and complicated.
Building a house with an attic or renovating an old building by building an attic floor is a great way to expand the living space of the house. The attic room can be used for a variety of purposes.
For example, you can make here an office or a gym for sports.Or equip here an additional bedroom for guests, plant a beautiful winter garden, make a game room for children.
In a word, everyone will decide for himself how to use the additional square meters. In addition, the attic floor can decorate the exterior of the house.
Drafting a project
You should not start construction without having a detailed project of the attic floor.
Neglecting this stage of work will lead to the fact that during construction insurmountable difficulties may arise, the elimination of which will require significant investment. So, how to calculate the mansard roof?
First of all, it is necessary to analyze the layout of the building to be converted. It is necessary to determine the size and shape of the future structure, plan additional elements - windows, a balcony, etc.
When planning, one should be guided by the requirements of building codes, in particular SNiP 2.08.01-89. For example, many private planners for some reason often forget the requirement that the intersection of the façade wall and the roof line should be at a level not exceeding 1.5 meters from the level of the field.
Designing the location of this line above is strictly prohibited.
When choosing mansard roof options and creating a project, the following factors must be considered:
- roof geometry;
- Ensuring the joint work of engineering systems of the attic and main floors;
- Material for the construction of the house and details of the attic. The main requirement when choosing materials for the construction of attics is their low weight.
- roofing materials used.So, attics with steeply sloping roofs require increased attention to the selection of material for waterproofing, thermal protection and roofing.
With these factors in mind, the project is developed. The mansard roof can be one- or two-level, just gable or gable with a broken silhouette. There are a lot of project options.
Naturally, it is extremely difficult for a non-specialist to understand all the nuances and draw up a competent project. Therefore, this stage of work, it is desirable to carry out under the guidance of a professional designer.
Assembling the truss structure
Rafter trusses are the main element of the mansard roof. Therefore, when answering the question of how to properly make a mansard roof, the main emphasis should be on the competent assembly of this supporting structure.
It is extremely important that the assembled system be strong and reliable, so it will have to withstand not only the weight of the roof, but also withstand external influences - wind, snow, rain.
Therefore, when calculating and drawing up a project, not only the type of building materials that are planned to be used are taken into account, but also the climatic conditions in the area where the house is being built.
As a rule, the wood of coniferous trees, most often larch and pine, is used for the manufacture of rafters. In this case, the moisture content of the prepared material should not exceed 22%.
An important condition is the preliminary impregnation of the wooden components of the structures with compounds that allow them to be protected from:
- fire;
- mold infestations;
- Insect infestations.
For these purposes, flame retardant and antiseptic compounds are used.
Rafters can be:
- Inclined;
- Hanging.
If the first option is selected, then the rafters at one end will rest on the load-bearing wall through the Mauerlat (bearing rafter). The second end rests in a rack or run.
In the ridge of the roof, the ends of the rafters are connected with overlapping nails or using overhead dies.
Advice! Racks are installed on load-bearing beams if the floor is wooden. If reinforced concrete slabs are used for floors, then the racks can be placed in any convenient place.
When attaching the Mauerlat to brick (gas or foam concrete) masonry, a double layer of roofing material is laid between the timber and the wall. The Mauerlat is fixed to the wall using studs or antiseptic plugs, which are installed during the construction of the wall.
To ensure the stability of the system, the installation of diagonal braces and struts is used. And to prevent deflection, a horizontal crossbar is mounted.
If the house has a large width, it is more profitable to use hanging rafters, which are pulled together with an additional element - a puff.
It must be remembered that the design of the attic roof requires an accurate calculation. It is unacceptable to build truss systems, focusing on existing practical experience without making the necessary calculations.
Recently, builders have begun to use, in addition to wooden elements, metal ones in the manufacture of truss systems.
Such a decision can be justified, however, it should be remembered that due to the difference in the thermal conductivity of metal and wood, serious deformations can occur.In addition, when assembling such systems, it is extremely important to perform thorough waterproofing at the junctions of metal and wooden elements.
Attic insulation
The next step in solving the problem of how to assemble a mansard roof is to insulate the roof and protect it from moisture penetration from the outside.
The attic floor needs high-quality insulation, as it has too much contact area with the environment.
Most often, mineral wool is used for insulation. This fibrous material has excellent insulating properties and allows you to create a dense layer.
But in order for the mineral wool to remain dry, it must be protected from moisture penetration, both from inside the room and from the outside. For this, special membrane films are used.
The highest requirements are imposed on the quality of the attic floor insulation, especially when it comes to building a house that is planned to be used all year round.
As a rule, a roof attic device involves the use of the following multilayer structure:
- The first layer is the interior. This can be drywall, plywood sheets or other sheet material that forms the ceiling in the attic.
- The second layer is a vapor barrier film;
- The third layer is mineral wool or similar insulation;
- The fourth layer is a waterproofing film laid so that moisture can freely escape;
- The fifth (outer) layer is the roofing. It can be a metal tile, soft roll material, etc.
It should be noted that the insulation of the attic space includes not only the competent manufacture of the mansard roof, but also the insulation of the front wall of the house, as well as the floor.
It is equally important to ensure sufficient ventilation of the mansard roof.
This will protect the premises from dampness and the growth of fungus on the walls. One of the conditions for properly done ventilation is to provide a sufficiently large gap between the insulation layer and the roof.
Advice! The thickness of the air gap between the roof surface and the insulation should be within 2.5-5 cm, depending on the type of roofing material used.
window installation
When building an attic floor, an important point is the installation of windows.
There are two possible options here:
- Vertical window installation;
- Inclined or pitched window installation.
The first option is more complex, as it requires the installation of a separate truss system to accommodate each window. The second installation option is easier to perform.
In addition, by installing slanted windows, more light will enter the room, so it will be easier to solve the problem of lighting.
It is believed that in order to achieve the optimal level of illumination and microclimate in the attic, it is necessary that the windows occupy about 12.5% of the entire surface of the walls.
In the manufacture of attic windows, a special type of glass is used, which is able to withstand strong wind and mechanical loads. But even with a strong impact, such glasses do not break with the formation of fragments, but crumble into granules that do not have sharp edges that can cause injury.
conclusions
As can be seen from the above, the construction of the attic floor and the installation of the roof require not only serious labor costs, but also a professional approach.
Therefore, it is necessary to carefully study the theoretical issues of building this element of the house and be sure to consult with specialists both at the stage of drafting the project and at the construction stage.
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