The appearance of the house and its service life directly depend on how the roof protects the ceiling, how well it will drain water from the basement and from the walls. In our article, we will talk about how to make rafters for a house, taking into account all the advice of experienced craftsmen and excluding the most common mistakes.
Despite the fact that there are many types of roofs, two types are most widely used in individual suburban construction: shed and gable roofs.
Roof types
Shed roof has the simplest design, which even a person who is far from construction can master.But such roofs are mainly used in the construction of auxiliary and outbuildings.
For residential premises, gable or broken (mansard) roofs are most often equipped. Despite some design difficulties, it is quite possible to build such a roof on your own, if you listen to the advice of the masters and do everything step by step, slowly, according to a preliminary project plan.
Hip roofs have a very complex structure and are quite labor-intensive. The arrangement of such roofs should be trusted to professionals. However, hip roofs are the most reliable, they will withstand even especially strong wind loads.
A four-pitched (hipped) roof is used for square buildings. In fact. It is a kind of hip roof.
Of all the above roofs, the most difficult is the cross. It has complex structural elements - grooves (valleys). Such diagonal auxiliary rafters must be installed additionally.
This is a very laborious work that does not tolerate haste and sloppiness. Snow usually accumulates in these places, and the quality of the roof and its reliability depend on how competently this constructive part is performed.
Each of the above types of roofs consists of two main elements: the roof and do-it-yourself roof rafters. The roof is the enclosing part of the roof structure, the rafters are its load-bearing part.
The main types of rafters
Before making rafters, you need to find out their design features and decide on the option for their arrangement.
In roofing construction, there are two types of rafters:
- Hanging.
- Layered
hanging do-it-yourself rafters - obliquely mounted beams on supports with different heights.The outer walls of the house (single roof) or the outer and inner walls at the same time (gable roof) often act as a support.
It is not at all necessary to fix the rafter legs opposite the slopes in the same plane of the roof. They can be laid alternately on the ridge run.
Such an alternate connection of the rafters in the ridge allows you to equip a construction truss. To do this, you need to tie all the elements of the hanging rafters together into a rigid single structure.
It is important to know: the roof truss must be installed on the extreme two supports. Thus, due to the lack of internal support, the rafter legs will rest against each other in the ridge joint, creating a rather strong horizontal pressure. If the load distribution is incorrectly calculated, then the thrust, being transferred to the walls, can even overturn them.
In order to eliminate such a mistake, experts advise making a puff belt at the bottom of the truss truss. Its main mission is to extinguish the emerging thrust.
What types of truss systems are preferable when building a country house?
There can be no single answer to this question. It all depends on the design of the house, the expected load on the roof and the choice of roofing material. Yes, layered rafters have a simple device, their assembly does not require complex devices and mechanisms.
In contrast, hanging rafters can even be assembled on the ground, but will require additional machinery (such as a truck crane) to put them in place.
Hanging rafters can also be assembled from individual elements right on the house. Further work depends on how to properly install the rafters.
So, it is important to know: you need to make a boardwalk on the attic floor. And in order to temporarily attach the parts, you will need auxiliary jointing and braces made of boards.
Materials for rafters and their connections
Rafters are made from beams or boards. For this, coniferous wood is usually used. The thickness of the board should be at least 40-60 mm.
Moreover, all wooden structures should not have flaws in the form of knots and cracks, well dried. Since logs are heavy, many roofers do not recommend using them.
But the rafters from the boards are convenient to mount and they are light in weight. You can even work with such material on your own, without resorting to the help of specialists.
Most experts do not recommend making joints on nails, self-tapping screws are preferable, but even if you decide to work with nails, then do not forget to use liners and linings.
Important: to connect the racks of the truss system with a bed or run, we recommend using notches.
There are three options for assembling the truss system:
- with racks
- With braces.
- With racks and struts at the same time.
Consider how to properly make rafters. Depending on the size of the span between the outer walls, you need to use:
- use boards for racks and rafters;
- timber 10x10 cm - for the design of the ridge run;
- mauerlat and bed can be made from logs, hewn them into two edges or from the same beam (10x10mm).
When making a ridge knot, it is important to nail special clamps made of steel strip with large nails to the run and to the Mauerlat.
You can do without steel clamps, but then you will have to use thick wire twists (with a diameter of 6 mm).
How to make the right rafters for a stone or brick house? A continuous mauerlat is laid on brick or stone masonry.
In order to securely fix it, we recommend placing a piece of timber or log (about 50 cm) under each rafter leg. And then, with the help of clamps, fasten to metal hooks, they must first be installed below the Mauerlat by 30 cm.
How to make rafters in cobbled or chopped wooden houses? In wooden buildings, rafters are laid on the upper crown of the wall.
Secure with clamps, which are nailed to the second crown. A rafter plank farm can be equipped with spans (6-8 cm) or with the help of a crossbar.
We equip the structural elements of the fert as follows:
- Single tightening with boards, the thickness of which is the same as on the rafters.
- For double tightening, boards slightly thinner (more than 40 mm) can be used.
- For overlays and crossbars, use boards with a thickness of 30 mm.
Let's look at an equally important question: how to properly assemble the rafters, ensuring the rigidity of the roof in different directions? If the truss truss has the necessary rigidity, then this is quite enough for the longitudinal direction.
But, in order for the roof to be able to withstand wind loads, it is necessary to install a pair of diagonal ties in the transverse direction, and in each of its slopes.
A word of advice: diagonal ties can be arranged using a board 30-40 mm thick. For layered rafters under the ridge and between two neighboring drains, we recommend installing braces.However, in the event that you plan to make a diagonal (oblique) flooring along the crate, then you can not do the braces.
Determine the required section of the rafters
Several factors on which the cross section of the rafters depends:
- From the load expected on them (from the weight of the future roof and snow cap).
- From what the dimensions of the span.
- From the angle of installation and the pitch of the rafters (i.e. from the slope of the roof).
For central Russia, it is preferable to install a gable roof, the slope of which is 30 degrees or more, with a rafter pitch of at least 120 cm.
Consider the dependence of the cross section of the rafters on the length of the rafter leg:
- So, with a step of 300 cm, for rafters you can use boards with a section of 8x14; 6x14; 4x18 cm or bars with a section of 10x12 cm.
- For a step of 400 cm, boards with a section of 8x18 can be used; 6x20 cm or bars with a section of 10x16 cm.
- For a step of 500 cm, you can use boards with a section of 8x22 cm or bars with a section of 10x20 cm.
- In those structures where struts were used, the height of the board or beam can be slightly reduced.
Now that you have learned how to properly assemble the rafters, you can safely get to work. To make it easier to lift and move wooden structures, call a friend for help.
After the rafters are installed, you need to do the roofing. Try to plan and carry out such work as quickly as possible in order to protect the truss system from possible wetting. It is best to do this in summer sunny weather.
It is necessary to choose a roofing covering taking into account the slope of the roof and its steepness.It is quite clear that the choice of a roofing coating also depends on the material possibilities, not only during the initial installation of the coating, but also during its subsequent operation.
It is important to consider: the steeper the angle of inclination of the roof, the more money will be required for its arrangement. This is due to an increase in the consumption of necessary materials. But, at the same time, steep roofs drain rainwater and snow much better, respectively, they perform their function at 100%, and therefore they will also last much longer without repair.
Despite the fact that at present the market of roofing materials pleases with a variety and a huge choice. Yet a universal roofing material has not yet been invented.
Such that it was inexpensive, and suitable for a variety of weather and climatic conditions, was light and durable.
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