Wooden roof construction

It is no secret that the roof plays an important role in the construction of the house. In turn, the roof itself is a complex system that must be distinguished by reliability and durability. Recently, it has become popular to make the top of buildings from wooden structures, besides overlapping it with natural materials. Then we will talk about how to make a wooden roof and what designs are used to make it.

Types of roof structures made of wood

When building low-rise buildings, roofs made of wooden structures are quite popular, which are divided into 3 types:

• on the basis of rafters on the slant type;
• on the basis of rafter types;
• on the basis of wooden trusses.

Suspended rafters are installed in such a way that their ends, on the one hand, have a lower support in the form of a mauerlat, and on the other, lean on the wall of a building or a rack. The task of the mauerlat is to receive and disperse the load that is transmitted from the rafters to the bearing walls.

Rafters are located at a distance of 0.6 to 2 m. The definition is influenced by the load and the type of wood. A bar is used as rafters, which has a cross section of 0.2–0.2 m or several planks with a thickness of more than 5 cm. Racks should be 2–3 m apart.

In order to increase the rigidity of the wooden roof rafters, the racks are tied together horizontally with boards up to 0.2 m wide. In order for the truss system not to be demolished by air currents, it must be fixed to the building surface. For this purpose, a twist of wire is used, which is fixed in the wall with anchors. Such a truss structure is currently most in demand because of its convenience. It can always be adapted to the shape of the house.

Note! In order for the truss system to be mounted, at least one longitudinal load-bearing wall is needed to fasten it. At the same time the building in width should not be less than 7 m.

If there is no bearing wall in the middle of the building, the construction of a wooden roof made of hanging rafters is used, which do not have such an upper support as in the previous version. The width of the building in this case should not exceed 8 m. Such a system is used for small buildings of economic purpose. The rafters below rely directly on the outer walls, which are affected by considerable horizontal stresses. The rigidity of the system is provided by a coupler rafters, which levels the spacer effort. Fixing all wooden elements is due to bolts, nails and metal plates.

Note! If the attic room is planned to be operated, the screeds should be positioned as high as possible.

Wooden trusses are rarely used in the private sector. Such structures are used in buildings, where the spans reach values ​​up to 20 m. The design of the farm is quite complex. It consists of nodes, elements of which are beams with a cross section from 50 to 150 mm. Such structures are used in old buildings that require roof repairs. In modern construction, these systems can be used in the construction of large barns.  

Roofing materials

To overlap the roof, you can use materials made of wood. Among the products for laying roofing can be identified:

• shingles, which are wooden plates that are formed through cutting and are joined to each other with the help of spikes and grooves;
• shindel - small punched wooden plates that resemble free-form tiles;
• the plowshare, which is a type of spindle, has a spade shape with a curly bottom;
• Tes, which is made of coniferous wood, and is a cut board with a sample along the edge;
• shingles - uncalibrated wooden plates that are small in thickness and are formed from aspen and alder by the method of chipping;
• chips, which is a kind of shingles, but inferior to her in length.  

When constructing a roof of planks, it is necessary to know that such overlap is used mainly when equipping pitched roofs, the angle of which does not exceed the value of the right angle. For steeper roofs, much more material is used, which makes it possible to increase the durability of the structure.

Roofing of shingle, shindle and plowshare

Depending on the roofing material, the technology for performing the installation of the roof elements changes significantly, and the type of rafters changes. Construction of a wooden roof can be made by different elements.

Shingle roof overlap is considered one of the most difficult methods. To independently make such a roof, considerable practical experience is needed. The size of the wooden plate reaches a length of up to 0.7 m, width - up to 0.15 m. The wood plates are cut from the boards. The disadvantage of this material is the roughness in place of the cut, which contributes to the increased absorption of moisture. To reduce this minus, the sawing should be carried out in such a direction that the fiber structure would correspond to the natural one.

One side of the plank is hewn along the length to such an extent that the thickness of the product reaches an average size of 4 mm. On the other hand, a groove is cut or hollowed out at the end, the depth of which reaches 1.2 cm. The groove at its end point should have a width of about 4 mm, which corresponds to the size of the hewn wedge. Among the types of wood that are suitable for this type of roof, we can mention oak and aspen, as well as pine. Before laying the plates, a lathing, constructed of a bar in the section size of 4? 4 cm or 5? 5 cm, is equipped for their fastening. It should be performed with a certain distance between the slats. Laying wooden blocks should occur along the axes with a step that is equal to one third of the length of the shingle plates. The crate can also be made of solid boards.  

All planks must be laid in a row in a direction in which all the grooves would look in the upper side. The next row is set in such a way that the gont wedges enter the grooves. After laying, each element is fixed with a nail to the bar at the top of the plank. Nails must enter a depth of 2.0 cm in bars. It is necessary to know that the wood species dictate the choice of nail material. If the roof is covered with larch material, copper nails are used. Galvanized fixings are suitable for other breeds.

Reliability and durability of the roof depends on the number of layers of stacked shingle:

• 2 rows - the upper layer hides the bottom one 1/2 times the length of the plate. Used for simple buildings.
• 3 rows - the top layer hides the bottom one for 2/3 of the shingle length. Used for residential buildings.
• 4 rows - the top layer hides the bottom one 3/4 the length of the plank. It is used for structures with increased responsibility.

Elements of the roof stacked on each other in a run. This means that the lower part of the plate, which is located in the upper row, covers two halves of the lower plates. The joints of the elements with the figured butt, called the gutters, are stacked in the fan position. To make such a formation, the narrow ends of the plates are given the desired slope at the bottom, and the planks in this place take the form of a trapezium.

Note! As is known, a tree has a tendency to be influenced by natural phenomena. To extend the life of the product, the shingles must be subjected to antiseptic treatment. In addition, the tree also burns. Therefore, the elements of the roof need to be further treated with flame retardants.

The principle of laying shindel and plowshare is similar to the previous one. Since these wooden plates are inferior in length to the shingles and reach only 0.4 m in size, crate slats need to be fixed accordingly more often than in the previous version. In the plates of this type there are no connecting grooves, therefore, the construction of a wooden roof is done by means of butt-packing.

Note! Since, as a result of precipitation, the roofing material swells, there should be a gap between the planks, the value of which should be about 4 mm. Otherwise, after some time the roof will be warped.

When the weather is humid, with such a design feature, the joints converge tightly, and on a sunny day, dry wooden elements allow air to create ventilation on the roof.

It would be wrong not to mention one of the types of wood, which has several advantages over other types of roofing natural material. This is a larch, which has the following advantages:  

• the presence of tar and high density does not lead to corrosion and insect infestation;
• high durability;
• wood looks beautiful due to its structure;
• The price of the material is relatively low.

The device of the roof of shingles, wood chips and Tesa

If the roofing material of the roof of wooden houses is shingled, the covering is made in 3 or 4 layers, and the overlap is maintained in the horizontal and vertical direction. For shingles are used boards from 0.4 to 1 m in length, from 0.09 to 0.13 m in width and approximately 4 mm in thickness. In the long side shingles fit in the same rules as shingles. The plates, which are located side by side, must be hidden to approximately 0.3 m. The next horizontal row should be laid so that the middle of its elements coincides with the junction of the plates of the lower layer. Each plate is fixed with a shingle nail measuring 70 mm in length and 1.5 mm in diameter to each strap-on bar. The ridge is equipped with a construction of 2 boards, knocked together to form an angle.

The overlap of chip elements is done on the same principle. The difference is only in the shorter length of the plates. Plates from 0.4 to 0.5 m in length, from 0.07 to 0.12 m in width and 3 mm in thickness are used for chips. For this material, the battens of the batten are tightly fastened - the pitch is 0.15 m. For comparison, when laying shingles this distance is 0.3 m. Since these boards weigh relatively little, can the size of the structural element for the batten be 4.0? 4.0 cm. For a great convenience of installation under wooden plates, you can prepare a continuous type of crate.

The roof with a wooden coating, the construction of which occurs with the use of tesa, is considered the most simple and cheap. The durability of such overlap is significantly inferior to other species. The fact is that when sawing wood, the natural structure of the raw material is broken, and the planks can no longer fully resist the effects of natural phenomena. However, there is another method of manufacturing elements. When splitting the workpiece along the length of the structure of the fibers is not disturbed, as the rift passes along them. The natural properties of wood are preserved. One hundred years of operation of such a roof is considered a normal term. The roof from tesa is mounted in 2 ways: cross and longitudinal. In the first case, the laying is parallel to the ridge. This method is simplified and is used for buildings with a short lifespan. The boards are fixed to the crate with nails in the bottom-up direction, while the top layer hides the bottom one at 0.05 m. There are 3 types of longitudinal methods: 

• Two rows fit close together. Elements of the upper layer fall on the bottom with an offset half of the plank. The gap between the plates for swelling is left around 5 mm.
• Along the slope, the styling goes in a run. The bottom layer of the plates is laid with a layer of 5 mm and hides under the top at a distance of 5.0 cm.
• With padded cover. The bottom layer has a solid surface. The joints are overlapped with smaller planks that extend to the bottom row by 5.0 cm.
• For all types of laying, the upper plates are fixed to the bars with 2 nails in each strip. The crate is made of wood structural elements, the distance between which should vary between 0.6–0.8 m. The thickness of the boards used should be from 0.019 to 0.025 m. 

Note! It is undesirable to install steam and waterproofing under the roof of wooden elements due to the fact that because of them the roof can not breathe and its service life will decrease. When overlapping the roof with natural material in the attic there is no condensate, as the tree has a low thermal conductivity.

Video

This video shows the process of finishing the roof with shingles.