Whatever the roof, it presupposes the presence of several basic elements, among them the rafter frame, the sheathing and the roofing package can be distinguished. As for the rafter system, it is the main supporting element of the roof, which is also sometimes called the skeleton. The lathing is the ribs on which the covering material is installed. The varieties of rafter systems can be reduced to two main classes, among them hanging rafters and those called layered.
If it is necessary to fasten the rafters to the Mauerlat, then you need to remember that the first of them can be layered. In this case, the rafter beams, which are located at an angle, have two points of support at the ends, namely the Mauerlat and the ridge bar. The latter rests through intermediate racks on the wall of the building located inside. A massive longitudinal beam can also act as a support.
DIY gable roof rafter system
Before starting the device of the gable roof rafter system with your own hands, you need to determine its type and calculate the need for materials. The hanging system is suitable in cases where an internal load-bearing wall is not provided for in the building structure, or if a spacious attic space is needed, for example, for the construction of an attic. The amount of lumber is calculated based on the floor area and roof height.
Helpful advice! The rafter legs can be fastened together on the ground, and not “in place”. This makes it possible to more accurately maintain the corners according to the template. In the case of a hanging structure, this method is the only one possible. Ground-mounted triangles are simply set in place and secured.
Do-it-yourself installation of the rafter system
The procedure for carrying out work during the construction of a rafter structure may be as follows:
- installation and fastening of the Mauerlat on external walls. It fits on the side where you plan to tilt the roof. It is preferable that these walls are parallel to the inner load-bearing wall of the building. It is necessary to put a layer of waterproofing of any type under the timber;
- laying the bed is done similarly to the construction of the Mauerlat;
- racks are vertically installed on the bed. You can fix them in a groove or metal corners. The angle at which the roof is inclined directly depends on the height of the racks, so if you want to make a roof with a given angle, then you can calculate the height of the racks using the simplest trigonometric formulas. For example, for an angle of 45 degrees, it is necessary that the height of the posts be equal to the distance between the Mauerlat and the bed. The distance between the posts must correspond to the desired distance between the rafters of the gable roof;
- all racks are connected to each other with a skate, which should lie strictly horizontally.
On this, the device of the main supporting elements can be considered complete. The next step in the construction of a gable roof rafter system with your own hands is the installation of rafters.
Gable roof rafter system
Preparing for installation
Before installing the rafters, they should be prepared for installation. For this, the following work is being done:
- The first step is to check the quality of the material. The rafters must be level and free of mold. Also, the material must have a certain moisture content, which should be 10-15 percent;
- The rafters are made of wood. This material is “afraid” of mold, moisture, insects and fire. Therefore, before placing the rafters on a gable roof, they should be processed. For these purposes, special impregnations are used. In order for the rafters to be well saturated, it is advisable to first clean them of dust and dirt;
- You should also prepare the fasteners. Most often, nails are used to install and secure the rafters on a gable or other roof. In addition, you can additionally use metal staples, special strips and steel wire.
And of course, you can’t do without tools. First of all, this is the usual carpenter’s set. You will also need an electric or chainsaw. To put the rafters, you will have to move around the roof. Therefore, boards must be placed between the floor beams. Also, we must not forget about safety. It is best to use scaffolding for the installation of rafters, if they are not there, then use a ladder of sufficient height and strength.
How the Mauerlat is attached?
There are several options for different buildings.
To install the Mauerlat in brickwork, threaded rods are monolithic, their minimum diameter is 14 mm, the depth of the bookmark is 450 mm. The surface is treated with bitumen mastic, then covered with a double layer of waterproofing roll material, usually roofing material or waterproofing. Having drilled a hole in the Mauerlat, it is installed, washers are put on the studs, then the nuts are tightened securely.
“Air” gas and foam blocks are not very durable, so you can immediately attach the rafter system to them. Therefore, first, a monolithic reinforced belt is created on them, in the process, metal studs are embedded in it with a certain step.
Holes are drilled in the Mauerlat in advance, then it is pushed onto the studs, bolted to the belt. Waterproofing is made between wood and concrete. The simplest option is several layers of the same roofing material. Further work. fastening the rafters to the Mauerlat does not differ from the described “brick process”.
There are 2 more options for mounting the Mauerlat:
- For brick walls. steel wire. Take a material with a diameter of 4-6 mm. It is twisted several times, mounted in the masonry 3-4 rows before its completion. After the mortar has solidified and the waterproofing layer is laid, a Mauerlat bar is laid on the wall, it is fixed with a wire, its ends are twisted and bent against the wall. The main advantages of this method are low cost and ease of installation.
- For concrete structures. anchor bolts. This method is highly reliable. The anchors are welded to the reinforcing belt so that they rise by 30 mm above the already laid Mauerlat. A bar with drilled holes is laid on the walls, fixed with nuts and washers. The disadvantage of the anchor option is its high cost.
The assembly of the gable roof truss system begins with the installation of the Mauerlat. It should be placed strictly horizontally, therefore, before starting the installation, the horizontalness of the wall to which it is attached is carefully checked, if necessary, it is leveled with cement mortar. You can continue to work after the solution gains 50% strength.
How to cut gable roof rafters with the step off method
Depending on the system, this is a bar with a cross section of 150–150 mm or a board with dimensions of 50–150 mm. It is attached to the top row of the wall masonry. If the house is wooden, its role is played by the upper crown. If the walls are made of lightweight building blocks. foam concrete or aerated concrete and others. their rigidity is not enough to redistribute the load. In this case, a reinforced reinforced concrete belt is made on top of the last row of masonry, into which embedded fasteners are embedded. wire or studs. A bar or board is then planted on them.
There are several ways to connect the walls and the Mauerlat:
- In the masonry (in a reinforced concrete belt), a smooth rolled wire of large diameter is fixed (two ends stick up). Holes are then made in the board in the necessary places into which the wire is threaded. She then curls and bends.
- Studs of at least 12 mm in diameter are walled up in the wall. Holes are made under them in the Mauerlat, a beam / board is inserted) and tightened with nuts with wide washers.
- Having aligned the timber or board along the outer or inner edge of the wall, take a drill with a diameter of 12 mm and make holes for the anchor bolts. They (of the same diameter 12 mm) are hammered to the very cap, then tightened with a wrench.
The distance between the pins (wire) should not be more than 120 cm. Cut-off waterproofing must be installed on the wall (belt) under the Mauerlat. It can be rolled roofing material or waterproofing material in two layers, it can be smeared with bituminous mastic.
This method is ideal for buildings made of logs, since only this option is able to save the structure from possible deformation, which invariably accompanies the shrinkage of the structure. There are open and closed fasteners. The former include a fixed corner and a guide element. a plate perpendicular to it. It is bent independently. The travel of such an attachment can be from 60 to 160 mm. The closed device differs in only one thing. it is mounted already assembled.
When installing these mounts, several rules must be followed:
- rafter legs should extend beyond the walls of the building, regardless of the type of fastening;
- all elements must have the same dimensions;
- parallelism of all rafters is a necessary condition, otherwise the hinge joint can jam.
There are several combinations of sliding and fixed knots. The most common option is one rigid mount plus two movable ones. This method guarantees both the strength of the structure and its sufficient “mobility”.
How to fix rafters on a gable roof?
You will be able to build a reliable house if you build a high-quality roof for it. To do this, choose a good project, calculate how many materials will be needed for the construction of one or another part of the house. Fastening the rafters of your gable roof do it conscientiously.
Do not forget that you will need to make high-quality waterproofing throughout the house and on the roof, to insulate your home. Choose the best roofing material you can afford. For each type of roof, the rafters are made in their own way.
There is no need to build as you see fit. There are certain proven technologies for building houses. Study the instructions, buy the necessary materials and start on your own or with assistants to the construction of your home.
For example, according to the norms, the rafter system is considered reliable when it can withstand a pressure of 200 kg per m2. First, decide what kind of roof you will make over the house, and then study the installation features of the rafters for it.
About rafter legs
A large load falls on the rafters. the severity of the roof. They must be of high quality, reliable and well fastened.
The layered rafters include the following materials:
Rafter legs are of medium thickness bars. They are installed along the slopes. It is the rafters that keep the roof from deflection in one place or another. The weight load of the roofing is distributed to other parts of the roof.
Structures are made layered when there are too large girders between the posts located vertically. When you are given a project, then the step between the rafters will already be calculated there. The fastening of rafters on a gable roof should be such that the roof remains strong after installation and serves for a long time. There are pillars here that similarly support the roof.
When you just start roofing, you need to attach the Mauerlat around the perimeter of your walls. What it is? A large beam, it is attached to the load-bearing walls of the house using anchor bolts. Mauerlat is the basis for roof rafters.
Before assembling the truss, you must carefully trim all planks with joists and bars. They are cut obliquely.
At the top, where the base of the Mauerlat is, the rafters need to be fastened end-to-end using screws. Want to avoid cracks? Drill a hole slightly smaller than the screw itself.
Beginner Rafter Layout | Speed Square | Common Rafter
The most popular wood slings. They are preferred by the overwhelming majority of those under construction. The material is lightweight but durable. Both an experienced builder and a beginner who decided to build a house on their own will be able to work with him.
Why is it better to make rafters yourself?
- Short production times.
- Technological precision of all parts.
- The same, already adjusted dimensions of all structural elements.
But then be prepared for the following disadvantages:
- High cost (at least twice as high as if you planed the rafters yourself).
- Delay in delivery (especially in season).
- The use of low-quality or under-dried wood (and then “lead” the roof).
So convenience or quality? If this is not the first time for you to cut or cut something out of wood, feel free to start making rafters! This is how it all looks in real life:
Rafters in the construction world in simple language are usually divided into main ones, i.e. carriers, on which the roof is held, and auxiliary ones, which are inside the roof and serve as a support for hemming the ceiling and walls of the attic (if such is planned). The strength and reliability of the future roof depends on how accurately and correctly you calculate the rafter system in advance.
The rafter system of any gable roof itself consists of the following basic elements that you need to make:
- Vertical racks.
- Rafter legs.
- Ridge run.
It is better to entrust the calculation of complex roof structures with multiple elements to a professional, but you can cope with a small roof of a private house. To do this, you will need these simple formulas that will help you find out how thick the rafters should be, with what slope and what span:
We also invite you to use our free calculator.
Treatment with antiseptics and propylene
And at this stage it is already important to protect the future rafter system from biological destruction. You don’t want the roof to collapse after a couple of years of operation, do you? Therefore, be sure to treat the wood for the rafters with fire and biological protection.
The rafters are usually impregnated with an antispecialty, and on top they are treated with a fire retardant. You can also alternate this processing several times. If you use a universal impregnation, be aware that it usually contains products with different service life. For example, the fire protection will end before the bio.
But the choice of means for processing today is huge. These are universal protective agents, and a variety of fire retardants, and antiseptics. It is easy to decide: if you are building in a sufficiently hot and arid area, first of all use fireproof impregnations, which deprive the wood of its natural flammability. And if your house will stand where the air humidity is high almost all year round, protect it from decay.
You can, of course, use both drugs. but not mixing, otherwise all the material will deteriorate. You just need to choose one agent as an impregnation, and the second as a protective surface layer. Just try to breed everything in the concentration indicated by the manufacturer. But do not treat frozen or damp wood with anything: its fibers simply will not absorb anything.
Note that a brush or spray when processing rafters gives little result. complete immersion and subsequent drying are much better. Just use a regular container, cover it with a film from the inside and make a “bathroom” for future rafters. over, it is advisable to turn all this on the ground, as soon as you bring the material to the place, because in the finished rafter system, it will be difficult to get to the internal elements of the connections. And they are the most defenseless in terms of moisture ingress. Dry after processing the part so that all sides are ventilated, and at least 24 hours.
Do not forget also that wood, like any natural material, is biodegradable. Therefore, in addition to fire-bio-protection, it is important to consider waterproofing in all places where the rafter system adjoins the brick walls of the house, if any.
How to properly saw down the rafters of a gable roof
We install the rafters on the gable roof ourselves
Many people make such a design when the rafter legs hang down. The system is good for both home and sauna. Some work can be done on the ground, and then lift the bonded material to the installation site. There is relatively little lumber for such a structure, which will allow you to save.
1 triangle of rafters is required, which is made according to precise dimensions and adhering to the rules. The made rafters, which will have well-measured and fastened crossbars with ties, are pulled to the roof. Here they need to be placed in certain places vertically and very evenly. Attach them to the ridge with a Mauerlat.
Do this and it doesn’t matter what kind of rafters you installed: layered or hanging. When slopes are added to the structure, it becomes stiffer. Do not forget that the rafters are most often attached to a ridge beam with a Mauerlat. A reliable gable house will come out.
The strength of the roof depends not only on how the cuts were made correctly. Consider the following tips:
- For rafters, select high-quality materials, since even if you make accurate cuts, the bar may not withstand the load. You cannot save here, as this part takes all the load on itself.
- The attachment points with the Mauerlat must be free from wood defects, for example, knots. Although they are stronger than wood, vortices form around them, which break under the slightest load.
- When installing a roof, do not hesitate to ask for help, as this is a dangerous and responsible business.
A competently executed junction of the rafter leg and the Mauerlat guarantees a long service life of the structure.