The usual gable structure gives a relatively small amount of free space, so most often in the suburban construction a broken roof is created with your own hands. This solution is optimal even in the case when it is planned to create a living area in the attic, which means it needs to be insulated. This article is dedicated to this type of roof.
Content
Roof calculation
The calculation of such a roof, of course, is much more complicated than in the case when a conventional roof is being erected, but the result allows you to get incomparably more. It is worth saying that construction is not worth starting without making calculations, since it is unlikely that it will be possible to create a reliable roof "by eye".
When calculating the design, it is necessary to calculate the amount of roofing material that will be required and the total bearing capacity of the beams of the rafter system. The first figure is not difficult to find out, because if the dimensions and sizes of the roof are known, then it will be possible to calculate the required number of sheets of slate or other material quickly. To calculate the bearing capacity you need to know how to make a sloping roof, and also clarify the following parameters:
- specific weight of the roof covering;
- snow load;
- lathing mass (depends on the type of construction chosen and the cross-section of the beam);
- slope angles;
- rafter length;
- installation step and rafter section.
Of course, there are a lot of parameters, but knowing all of them and having minimal PC skills, you can use ready-made software packages designed to calculate roofs. After all the calculations are made, you can begin to purchase the necessary materials.
Materials and components
To create a broken mansard roof, you must first purchase the components for its frame. The basis of such a roof is a rafter system, represented by a structure made of timber, which in turn is based on a Mauerlat. Mauerlat is also a beam, but a slightly larger section. It is located along the walls and acts as a kind of foundation for the roof.
It is advisable to choose softwood harvested in winter. It is worth noting that the material must be dried thoroughly, otherwise there will be problems with the roof structure in the future.
When you create a broken mansard roof with your own hands, you need to process all the elements of the rafter system with antiseptics, since this will protect the tree from decay.
In the process of choosing the right beam, you need to ensure that the material is of high quality. It is necessary to pay attention to cracks, processing defects, knots and traces of damage by woodworkers. Delamination is also undesirable, therefore, a beam having a similar defect is rejected.
In addition to rafters, other wood elements are also used in the roof structure. As a rule, this is also a beam, which is used to create a crate and a counter-lattice. They provide ventilation of the subroof volume and serve to hold the roofing material. The lathing can also be made of plywood, especially when it comes to different types of soft tiles or rolled material. An alternative to the classic wood crate is a galvanized steel profile, which also copes well with the role of the base for some types of roofing material.
A variety of fasteners will also be required.For the installation of roofing material, the hardware recommended by the manufacturer should be used, and the type of products used to connect the rafters depends on the method chosen for this purpose. For example, it can be studs and special steel plates, which allow you to get a fairly reliable design.
Roof installation rarely requires the use of special equipment, but a standard set of carpentry tools will be a must. In addition, it is worth saying that the work performed at an altitude of more than 5 meters is best done using insurance, which means that additional equipment will be required.
In the process, it is better to comply with the rules of TB and use tools from. When working at height, a safety belt is required, since even a fall from 4-5 meters can end fatally.
We must not forget about waterproofing, for the device of which the presence of special materials is necessary. In the event that the attic is residential, then a heater and a vapor barrier will be required.
How to protect a tree
Good ventilation is required to protect the material of the rafters and crates, but one is not enough, because in the cold season the air humidity is quite high, and even during winter thaws it reaches very high values. In this case, the roof construction is saved by additional protection, which is created even at the stage of preparation of materials. Here we are talking about impregnation with antiseptics, which impede the development of any putrefactive processes.
There is a lot of information about the choice of antiseptic today, so this issue will not be covered in the article, and we will talk about the methods of application in more detail. There are not many, and the easiest option is to use spray guns. This approach allows you to cope even with a large amount of work in minimal time, but has a certain drawback. The main problem is that a broken roof with your own hands is more expensive, and the quality of the impregnation is not too high.
The second method is simpler and requires only the presence of a wide flat brush, with which an antiseptic is applied. The composition that prevents the development of decay should cover the tree in two layers. In fact, it is well absorbed deep into the material, so re-application is necessary to increase the penetration depth.
In the process of applying antiseptics and flame retardants, it is necessary to use personal protective equipment, including special glasses and a respirator, which prevents the vapor of these compounds from entering the respiratory system.
All work on impregnation with antiseptics and flame retardants is best done on the ground, highlighting a small area for this procedure. In this case, it is possible to process all the beams with the utmost care, which will be the key to their durability. An alternative is to impregnate the already assembled structure, but in this case many places are difficult to access, and the joints must be lubricated very carefully, increasing the consumption of the composition. In this case, a broken roof with your own hands will require more time, because some elements can be impregnated with an antiseptic only by loosening the studs.
Preparing the base for the roof
The first thing to do is to prepare the base for the rafters. The role of a kind of foundation is performed by a Mauerlat, which is a log or bar, which are laid on the top of the wall. It serves as the lowest point of support for the rafters and is designed to evenly distribute the load transmitted by the points of support of the rafters to the area of the upper part of the wall.
Between the Mauerlat and the wall material, there must be a layer of waterproofing material, such as roofing material, which will protect the wood.Otherwise, sooner or later, rotting of the beam may begin, which in the future will lead to damage to the roof. Mauerlat can not be represented by a solid bar, but by individual elements that fit under the rafters.
For the role of Mauerlat, it is worth choosing a fairly thick beam. Typically, in such cases, a section of 150x150 or 100x150 is used, since this element takes a significant part of the load from the roof.
Those who know how to install the roof of the house can offer another option, which is suitable for buildings made of aerated concrete or brick. He suggests that a reinforced concrete belt will be used, the formwork for which is mounted on the top of the wall.
When the base for the roof is prepared, you can begin to create a roof frame.
Installation of the rafter system
Rafters - this is the skeleton on which heat-insulating materials and the roof itself are held. The rafters themselves are best combined according to a template made in advance. Of course, you can do without it, but the presence of such a product will allow you to quickly determine the desired angle, and therefore, avoid possible errors in the installation process.
After the details are sawn according to the template, they are lifted up, where they are installed in accordance with the project. First of all, it is worth mounting elements such as side sections. They are held with the help of special technological stops, after which comes the turn of the upper sections, which are fixed together on the ridge.
When creating a broken mansard roof with your own hands, the size of the structure plays an important role. If it is large enough, it is best to use steel plates and studs, but in the case when you need to build a small roof, it will be enough plywood plates joined by self-tapping screws.
After the upper running beam is installed, the entire structure is fixed using braces, and then reinforced with vertical struts. Racks are made of coniferous timber.
Thermal insulation of a broken mansard roof
When the rafter structure is brought into line with the project, it is necessary to begin work on the installation of insulation. In fact, this procedure is divided into three stages.
The first of them is the laying of waterproofing material. It is performed on top of the rafters in accordance with the recommendations of the roll insulation manufacturer. As a rule, such materials are overlapped, and the joints are glued with special adhesive tape.
The second stage is the installation of thermal insulation material. When a broken roof is made with your own hands, rolls of mineral wool or a combined multilayer insulation are used, which is cut in accordance with the size of the openings between the rafters and laid with a small overlap. Installation of mats is done to the rafters to ensure reliable thermal insulation and the absence of cracks.
The next layer is a vapor barrier material. Its task is to protect the thermal insulation from the ingress of water vapor, which is necessarily contained in warm air. It is worth saying that waterproofing also helps to reduce the moisture content: it is permeable to steam, so it can easily go outside.
Roof installation
Laying of the roof covering is carried out in accordance with the requirements of the manufacturer. Those. There are no special differences in this case, and the different angle of inclination of the slope parts does not affect the installation technology.
You should not save on a counter grill, because it is needed to provide ventilation, which allows the moisture remaining on the waterproofing surface to evaporate quickly. The thickness of the bars for the counter battens is selected taking into account the type of roof.
The type of battens also depends on which roof is used.For example, if it is supposed to put a wavy slate, then bars from bars will be enough, and for a direct slate it is better to use a solid construction. In each case, the decision should be made in accordance with the type of roofing material.
In the event that it is not clear to you how the broken roof is done with your own hands, the video posted with us will highlight the difficult moments of installation.
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