Seam roof device

Recommendation points

• Supporting system for seam roofing
• Roofing cake and sheathing
• Selecting the format and type of panels
• Lifting and laying roofing material
• Seam seam and joint waterproofing
• Cornices, drippers and skates

Although folded iron roofs are not widespread, this type of roofing system is very popular due to its performance properties. We will tell you how to make the installation correctly at each stage: from the supporting system to the skates.

Supporting system for seam roofing

Seam roofing, profiled sheet and metal tile are the same type of cover, therefore there are very few differences in the structure of the supporting system. Depending on the type of building and roof configuration, the roof can be supported by rafters, trusses and a solid foundation such as a monolithic floor slab.

On civil construction sites, the most commonly used roof truss system is steeply sloping ramps. For the rafter legs, it is recommended to choose a board 50 mm thick and 150-200 mm wide. The necessary resistance to snow loads is ensured by varying the pitch of the rafters. If, according to calculations, it turns out to be less than 80-100 cm, the thickness of the rafters is increased, either using lumber of greater thickness, or knocking down a package of boards 50 mm + 25-40 mm.

The seam roof is attached to the horizontal lathing, therefore the installation of additional side girders is not necessary. However, with a significant length of slopes (more than 6-8 meters), it will not be superfluous to support the rafter legs with racks resting against the puffs, instead of increasing the section of the boards. Also, do not forget that a counter-rail is stuffed onto the rafters, so the cross-section of the legs will eventually be 50 mm higher.

Close attention should be paid to the rafter leg convergence. In this place, the outlet of the roof air vent will be located, therefore, the version of the system with a common ridge girder or crossbar may not be the most suitable. On the other hand, it is not forbidden to install exhaust cuts instead of a common ventilation slot in the ridge unit, although this leads to an increase in the cost of the roof. On the wind eaves of the roof, the rafter system should provide for the possibility of attaching a persistent bar or a frontal board with a ledge, respectively, the extreme rafter legs should be located as close as possible to the gables.

Roofing cake and sheathing

Roofs under seam roofing can be both insulated and cold. The entire volume of insulation is placed between the rafters and under them, respectively, the specificity of the pie arrangement just under the folded roof begins from the upper edge of the rafter legs.

The first step is to install drip strips along the entire length of the eaves overhang, then vapor barrier is installed. For these purposes, it is better to use a superdiffusion membrane; its service life is comparable to that of the coating itself. The membrane is stretched along the plane formed by the rafters, with a slight slack and is targeted with staples from above. Next, the counter lattice slats are installed, which is a 50×50 mm bar. This element performs two functions at once: it protects the attachment points of the hydraulic barrier and provides a sufficient ventilation gap.

A mounting lathing is sewn on top of the counter rails, to which the roofing itself will be attached. Roofers have several opinions about the type of lathing. Some argue that under a folded roof, the sheathing must necessarily be continuous, that is, either a tightly knit flooring of boards, or sheathing with sheet materials. As an argument, a qualitative elimination of the acoustic effect is given, which is why almost all types of metal coatings are ill. However, it makes sense to do this only when installing a cold roof, in other cases, a solid crate will make it difficult to ventilate the back of the coating, because the metal will adhere closely to the base. Therefore, for insulated roofs, the most suitable option would be a sheathing device made of edged boards with dimensions of at least 25×100 mm with an indent of 50-70 mm.

In principle, the seam roof can be installed directly onto the battens. All wooden elements of the roof must be necessarily treated with bioprotective impregnation and fire retardants; wood dyeing is often practiced to increase durability. If there is any doubt about the quality of the roofing material, the reliability of the locks or the qualifications of the roofers, it is better to provide additional under-roof waterproofing. This may also be required if the roof has too shallow slopes or is subject to accumulation of snow and ice. Euroruberoid or film insulation for roofs is perfect as a waterproofing agent. At the end of the preparation, eaves abutment strips are nailed along the entire length of the horizontal overhangs of the roof.

Selecting the format and type of panels

Roofing elements are called panels or, more professionally, paintings. There are three types of paintings, each of which has its own installation technology. When choosing a specific type of seam roofing, you need to evaluate both the amount of work and the complexity of the roof.

The most popular among private developers is the clickfalz type roofing iron. Its key feature is that the paintings are delivered in a pre-prepared set, require a minimum of trimming and are installed in the simplest way. Click-to-roll roofing does not require a special tool for rolling joints; moreover, a minimum of fittings is used during its installation. The disadvantage of such a coating is that it has the least reliable degree of sealing of the joints, so it is not suitable for slopes with a slope of less than 15 °.

ClickFall connection

The second type is the classic seam roof. The paintings are factory-rolled, their edges are bent so that later they can be easily joined and rolled up, while dullly sealing them. Unlike the clickfold, the panels do not have a side for hidden fastening, their installation is carried out using clamps, thus, the entire coating is arranged using floating technology. Due to this, the classic type of roof is optimal for sheltering long slopes, where the thermal expansion can reach several centimeters.

Classic seam roof

The third type of seam roofing is directly related to the classical one, the only difference is that the production of paintings is carried out directly at the facility. The machine, in which the unwinding and folding machine is installed, forms locks on the edges of the same type and shape as in the factory. The advantage of this method is that the picture is immediately made of the desired length for the entire length of the slope, in other words, the device of recumbent folds is not required.

Mobile folding machine

Lifting and laying roofing material

Seam roofing is made of the same iron as corrugated sheet and metal tiles. The material requires the same careful handling, because any damage to the polymer coating is fraught with rapid metal corrosion. The same requirements are imposed on the cutting tool: pictures cannot be cut with a grinder, only with punched shears or a hand-held circular saw.

Before the paintings are delivered to the roof, they are prepared on the ground. The panel is cut from the lower edge to bend the edge in the central flat part by a width of 20–25 mm at 180 °. With this fold, the picture will subsequently be joined with the cornice strip. Also, the panel is immediately driven into size in accordance with the length of the ramp. If one picture is not enough, its upper edge is folded into the lock under a recumbent fold.

Pairing with eaves

Each type of roof has its own strict installation sequence. As a rule, the roofing of the slope starts from the left edge for clickfold roofing and from the right edge for classic roofing. This is due to the location and type of locks; the method of fastening also plays a significant role. Before installing the first picture, a thrust bar 25 mm high and 50 mm wide is nailed to the crate. Instead, the flanging can be formed by a frontal board protruding above the plane of the sheathing to an appropriate height. The first picture is tightly pressed against the timber, then with the help of the Egyptian triangle the presence of a right angle between the timber and the eaves overhang is checked. If the perpendicularity is confirmed, the first picture is fixed with self-tapping screws in a corner under a bar, and then fixed on the back side with clamps or in a hidden board, in the latter case, the self-tapping screw is a little short to ensure the possibility of linear expansion.

After laying the first picture, a wind bar is installed on the timber. Its edge is cut and folded in a special way to protect the end of the frontal board. The plank is fastened with roofing screws with sealing washers both from above and from the side, while it is better to arrange the fastening in two rows in a checkerboard pattern with an indentation of 30–35 cm. Following the first picture, all the following are installed. They are first laid without snapping the lock, then pushed up to close the curtain rail lock. After that, the fold is snapped into place with a mallet or hands, then the reverse side is fastened.

Fastening the folded sheet with clamps

The final picture, as a rule, requires a longitudinal trimming, with the exception of ready-made roofing kits, in which the additional element is prefabricated. The picture is cut under a thrust bar, leaving 25 mm for the edge bend. After that, the edge is folded up using a manual edge bend and the panel is mounted in place. To securely fix the bent edge, you can use clamps or a lock remaining on the trimmed part of the picture. After that, the final panel is covered with a wind bar, on which the laying of the roofing material on the slope can be considered complete.

Seam seam and joint waterproofing

Only the click-fold roofing does not require rolling the seams, for the classic type this is a mandatory requirement. During the rolling process, the edges are pressed tightly, which ensures an unprecedented degree of sealing. However, even such measures are not enough, for example, for recumbent folds or with a manual method of seaming..

Double standing seam

It is possible to improve the waterproofing of the joints with the help of sealing strips, which are glued to one of the contacting surfaces of the folded lock. Lying folds almost always need such a seal; for standing folds, this option can be provided only with prolonged accumulation of snow cover on insulated roofs. You also need to remember that there are double seams, the seaming of which is performed in two passes. For this type of connection, it makes no sense to use sealing tapes, however, seaming should be done mechanically.

Frame for forming a fold

Seam folding is an irreversible process, therefore it is performed at the final stage of installation, when all the pictures are laid and docked into a single covering. The folds can be closed manually using a set of pliers, this is the most time consuming method that does not guarantee high-quality sealing of the joints. The mechanized method involves the use of a special seaming machine, which is installed on a lock at the bottom of the slope, and then itself drives along the entire length of the fold and compresses the metal tightly with rollers. The machines are available in one and two ways for single and double folds, respectively..

Seam roof seamer

The closing of the reclining folds can be done as the floor is laid. It must be remembered that the possibility of thermal expansion is provided not only by the roof fasteners, the recumbent fold itself also has a small internal gap. As a rule, recumbent folds are closed manually, they are simply carefully beaten off with a mallet. To do this, it is imperative to provide for the presence of a lathing board under the place where the paintings are joined..

Cornices, drippers and skates

The description of the seam roof installation captivates with its simplicity, but in reality it is one of the most time consuming and difficult to install types of roofing. Indeed, there is no problem to lay a folded roof on a flat slope of a small length, however, the situation changes dramatically when working with valleys, cornices, when bypassing roof chimneys and under-roof ventilation.

Making high-quality seam roof joints is impossible without special skills and experience in working with roofing iron. Also, you can not do without an impressive set of tools: up to ten types of scissors, hand bending benders, mallets, mandrels, bevels and many more various devices. Therefore, a private developer can be recommended to save only on self-covering of simple slopes, while all junctions, valleys, as well as cornice and wind nodes should be performed only by a qualified master.