Before taking on the construction of the most interesting and convenient design roofs, it is worth correctly assessing what advantages and disadvantages lie behind the attractive external facade of the idea. The hip roof is no exception. It is worth noting that making a hip roof is a rather expensive pleasure that requires funds, knowledge and practical experience.

Features of the hip roof structure

If you look closely at the classic hip roof, it becomes clear that it was created, first of all, for two-three-storey buildings, for conditions with big amount precipitation and changeable direction strong winds... No wonder such designs are also called Dutch or Danish. This is where the benefits are hip roof obvious. But the beauty of the structure sometimes forces hips to be made precisely for the sake of the appearance of the roof and facade of the house, and not for some special properties.

If we compare the dimensions and material costs for a gable layout and a four-pitched hip roof, the following conclusions can be drawn:

• It is profitable to make two additional roof slopes instead of flat gables because of the lower costs for a wooden frame beam, but it is unprofitable from the point of view of the consumption of roofing materials;
• If you make the walls of the house from modern aerated concrete blocks or bricks from wood concrete mixture, this will reduce heating costs, but significantly increase the cost of reinforcement supporting frame hip roof, by almost 25-30%;
• It is beneficial to make a roof with a hip structure if the house is in conditions of constant strong winds and heavy rainfall. In this case, heat loss on a gable roof is 5-10% higher than on a structure with hips;
• With the same consumption of materials, making a simple hip roof is more expensive due to the need to pay for the services of more qualified builders and specialists;
• A structure with hips, with one quality of construction, is considered more durable and durable in comparison with gable roof schemes.

Important! The hip roof today has become almost a classic of the genre in the architecture of low-rise construction of cottages and country houses.

Make a hip roof and not be mistaken

A hip roof today can look very beautiful and original. Modern developments of hip roof structures allow you to make it on almost any modern building, with or without foundation. If the building does not even have a strip foundation of normal depth, a hip roof can be made according to the simplest scheme - with a very small slope of the roof slope, a large extension of hanging rafters and a wide roof overhang. Naturally complete attic and the overlapping device will not be possible due to the weak stability of the box at home. This approach will make it possible to make the minimum aerodynamic load from the wind, good protection walls and foundations from rain streams, and will reduce heat loss through the tops of the house. A great option for a small country house.

Basic schemes for assembling a hip roof frame:

1. Construction with support only on walls, without the use of ceilings or ceiling beams;
2. The elevated version of the installation of the frame allows you to increase the size hipped roof in height;
3. A roof supported by floor beams of the house is the most commonly used option for houses with light walls with insufficient rigidity of the building box;
4. A hip roof supported by floor slabs is the most common option in modern construction two and three-storey houses.

Hip roof supported by slabs

Unlike conventional gable roofs, in which the angle of inclination of the flooring can be from 30 - 65 о, hip schemes have an optimal angle of 45 °. Almost all constructions and calculations are performed based on the specified angle of inclination of the main elements of the frame - diagonal rafters... This option provides maximum structural strength.

Using layered schemes and supports on beam floors

Most often, such a roof rests on the lower part of the rafters on a Mauerlat made of a bar or thick board, fixed to the upper end of brick or concrete walls future home. Together with the foundation, the walls form a rigid semi-closed system that can withstand vertical and horizontal loads from the rafters. The installation of a floor from a log, bar or board in such schemes is necessary to form the ceiling and attic floor. The overlap itself in holding the roof or individual elements does not carry a hip structure.

In the layered structure of the rafter supports, there is also usually a version of the ceiling, made of wooden beams... With the small size of the house, the specific strength of the overlap is enough to partially take on the load from the ridge run and rafters. If the length of the beam increases by more than 5 m, the strength of such an overlap is clearly not enough to hold the roof. Therefore, in the central part, support columns or even part of the walls are built, on which the central part of the floor beam rests. The load from the ridge girder is transmitted through the vertical supports-supports to one powerful central beam, called the bed. Sometimes the force from the weight of the structure is transmitted through the bed directly to the stone supports, without the participation of the ceiling itself.

Thanks to this scheme of redistribution of the load, the rafters can be thinner and lighter, and the pressure on the walls of the house is reduced by 30-40%.

Using a joist floor to support rafters

Often in the construction of a house, the ability of the main walls to hold the vertical load from the weight of the roof and frame is not always a decisive factor. A similar situation often arises in the structures of panel houses, in buildings with lightweight walls, or when using blocks with low rigidity as the main material for walls, for example, arbolite stone.

In these cases, even partial unloading and transfer of most of the pressure from the weight of the hip roof from the perimeter external walls to internal stone walls and support does not solve the problem. The rigidity and strength of the main frame of the building is not enough to reliably hold even a hip roof, not to mention gable scheme... The problem of additional rigidity can be solved by making a special overlap at the base of the roof from wooden beam, with a section of 20x20 cm or 20x15 cm. The beams are laid on top of the finished Mauerlat, with an overhang of the walls by 60-70 cm, with a step of half a meter. The overlap of the timber should be supported on one of the inner walls.

The ends of the timber protruding beyond the walls are used to fasten the lower parts of the rafter legs, and a frame with supports supporting ridge girder and the top of the rafters. The main part of the structure - diagonal rafters are installed in the corners of the floor and connected at one point on the ridge girder.

Hip roofs with supports on floor slabs

Structures with hip triangles have long become an obligatory attribute of two or three-storey cottages made of brick and stone, built according to the classical technology with laying ceilings from reinforced concrete slabs. Due to the high strength of the boards and brick walls the problem of ensuring the required rigidity of the supporting surface for the frame is not worth it.

To maintain the weight of the frame, the same scheme is used as in the layered version. A frame with vertical struts and struts, which receives the force from the ridge beam and rafters, rests on a bench fixed to concrete slab overlap.

Features of building a hip roof

The design allows you to withstand any wind load, but subject to precise adherence to the geometry of the connection of the four main diagonal rafters.

Accuracy of connection and geometry of rafters

All efforts can be in vain if the optimal angles of inclination of the hip rafters to the overlap and the angle between themselves are violated. The best option a scheme is considered in which the angular hip rafters are connected to each other at an angle of 90 °.

The optimal angle between hip beams- an important, but insufficient condition for the strength of the hip roof frame. If you look at the roof frame in profile, both hip planes should have exactly the same size and the same angle of inclination. IN otherwise the structure will be overloaded to one side, and this is the first step towards deformation and destruction. If you look at the frame from above, you can see that with perfect assembly, the opposite corner hip rafters should be parallel.

Methods for connecting beams and rafters of a hip roof

Despite the efforts being made to unload part of the structure, it is difficult to make the frame absolutely ideal in terms of the arrangement of beams and load-bearing elements. Therefore, in all main power beams and rafters, metal overhead plates and wooden overhead elements are used for fastening and fixing to the walls.

Most often, the beams and rafters at the setup stage are grabbed by a "rough draft", the easiest way to do this is with self-tapping screws and clamps. After adjusting the dimensions of all connections, you need to check the position of the beams and rafters, then all fasteners are connected finally, it is easier to do this with nails, hammering them in pairs at different angles.

The first to fix the ligaments of the diagonal hips on the ridge run, while always checking the withdrawal from the calculated place of the opposite beams. This is the most responsible and difficult stage in the assembly of the structure, and it is important to do this procedure slowly and very efficiently. The qualification of the builder of hip roofs manifests itself precisely at this stage, all subsequent work is quite capable of doing an ordinary carpenter who has general idea about the device of diagonal rafters and hips.

The load on the diagonal of the hip roofs exceeds the force on the ordinary rafter more than one and a half times. Therefore, the first thing to do is knock out the tuned and fixed corner hips with struts and stops. Each of the retaining elements is individually adjusted and is also secured with reinforcement of the connection. At the next stage, it is important to correctly install the rafters and ordinary rafters; upon completion, you need to tighten the fastening of the rafter legs on the Mauerlat or floor beams.

Before laying the vapor barrier, it is imperative to do the treatment with preservative solutions. It is easier and safer, you can use the most popular formulations of Tikkuril in organic solvent.

Conclusion

It is not so difficult to make a roof with hips if there is a real specialist in the brigade who can be entrusted with monitoring the implementation of the main, especially critical joints of the power elements. It is possible to do these works yourself, without having practical experience in building hips, but the construction itself will stretch for several months, and the cost of spoiled material will just amount to the cost of the services of a qualified specialist.

Overlapping different types have their own installation technology, which should be strictly observed.

The general rule is that the ceiling is aligned with the ceiling of the lower floor. Since it is this that gives the structure of the house spatial rigidity, all its parts are rigidly connected to each other and to the walls (welding, concreting, anchors).

It is not allowed to punch holes in the floor slabs that are not provided for by the project (so as not to damage the ribs and reinforcement in the slab), shorten (cut) the floor slabs, or overload them during installation in excess of the standard load. The most common mistake is reducing the area of ​​support of the ceiling on the wall(compared to the design).

Consequences. Deflection and collapse of ceilings, cracks in the walls and on the ceiling (for example , permissible deflection for a 6 m span hollow core slab is 15 mm).

Elimination. If the deflection is greater than permissible, the load on the slab should be reduced or reinforced in the manner specified by the specialist.

How right. It is necessary to strictly follow the project and instructions on the technology of installation of floors. If, due to an error in the construction of the wall, there is a problem of insufficient support area, a specialist must develop a node for this section that allows it to be increased.

Roof construction mistakes

The attic wall is not reinforced

Consequences. Inclined rafters act on the attic wall in a horizontal direction, creating a thrust, which causes the wall to collapse.

Elimination. Convert a hanging truss system to a layered one.

How to do it right . When erecting an attic wall, it is initially necessary to provide for a layered rafter system (with a fulcrum in the ridge area).

The vapor barrier film is not hermetically installed

Consequences. There are pockets of steam penetration into the insulation, which is why moisture accumulates in the under-roof space.

Elimination. Disassemble the structure, inspect the rafters, replace damaged elements. The insulation must be dried or replaced.

How right. When installing the vapor barrier, the film around the perimeter of the attic is brought onto the walls. With a special wide mounting tape, they carefully seal the joints and places of abutment to structures. It is prohibited to use nails.

There is no ventilation layer in the roofing "pie"

Consequences. Moisture can accumulate in the insulation, which is why it loses its properties.

Elimination. Disassemble the structure, inspect the rafters, repair damage, and re-mount the roofing "pie".

How right. The roof space must be ventilated through an air gap that is left between the insulation and waterproofing film... Only a superdiffusion membrane can be laid on the insulation without a gap.

When installing bituminous and metal roofs(folded, metal-tile), under which condensation forms, the ventilation gap is also arranged directly under roofing... Under the eaves of the roof, holes are left for the flow of air, and in the area of ​​\ u200b \ u200bthe ridge, devices are mounted for its outflow.

The type of coverage has been changed to a heavier one

Consequences. The rafters die, as a result of which the roof deforms, begins to leak and can collapse.

Elimination. Strengthening the rafter system.

How right. When changing the type of roof, it is necessary to order a recalculation of the rafter system for a more massive covering from the design engineer.

Semyonovich, I did not find the answer in the internet to this question. Sabbat. in the reinforced concrete workshop, the total area is 80 by 24 meters, the slope is about 5 degrees, filled with bitumen. It is proposed to tie the rafters directly to it with wire to the floor slabs. But how, I can't imagine. It is clear that you need to drill holes in the slabs, but how to push the wire into one hole and pull it out again into the next one to tie the rafter? It is impossible from below, there is nothing to walk on. Maybe there is some other real and simple way of attaching the rafters, please advise. Insulation between the rafters is also assumed.

Alexey, Vologda.

Hello Alexey from Vologda!

A very non-standard question how to fix wooden rafters to the workshop bay. Therefore, the answer to it on the Internet is not visible.

More and more, similar ones are simply again covered with roofing material (rubemast, glass insulation and the like) directly along its old layers, including the layer of poured bitumen. Sometimes these old layers of the roof are stripped off. But this is, of course, difficult. New electrical installations completely fix the roofing material according to the old one, without removing it. But they are still a rarity for our great and immense.

I confess that I have never blocked the shop spans according to your method.

Smaller areas were accounted for in several other variations.

At the same time, we laid wooden beams (and boards), an analogue of your rafters, and fastened them to reinforced concrete slabs not with wire, but somewhat differently.

They took a steel corner with a shelf of about 63 - 75 millimeters, cut it with a grinder into pieces 50 - 100 millimeters long. Holes were drilled in these scraps on both shelves. For self-tapping screws, holes / 2 - 3 pieces / were made in vertical shelves (with a diameter of about 5 millimeters), and in the horizontal shelves one hole with a diameter of about 12 - 14 millimeters. (Alternatively, they took steel sheet 1.5 mm thick, cut into strips, then bent into a corner and drilled holes).

After that, the trims of the corner were applied with a vertical shelf to the surface of the wooden bar and fastened to it with self-tapping screws.

And the second horizontal shelf lay on the surface of the reinforced concrete slab.

Through the hole in the bottom shelf of the corner, a recess was drilled with a perforator in the plate or through hole(when it was opposite the cell-cavity of the plate).

Then they took the anchor bolts (you can use a wedge anchor), insert them into the hole, and drive them with a hammer. Then, with a drill with a bolt head, the anchors were screwed in all the way. True, the number of anchors was decent, but they are not cheap.

We got a completely normal mount. The following features were taken into account.

First, we calculated the approximate pitch of the reinforcement, which was in the reinforced concrete floor slabs, so that the perforator would not get into them and the anchor could be pushed in.

Second, when looking from below, the view was not always presentable, there were potholes on the surface of the slabs in some places (where the drill bit fell on large rubble, component part concrete, and it fell out.

Third, the rafters were not immediately fastened to the slabs, but the longitudinal logs. And only then they put rafters on them and fastened them with brackets, nails, screws. So it turns out fewer points of fastening, respectively, less laboriousness.

All the pieces of wood were impregnated with KSD, "Senezh". This is what the customer demanded in accordance with the regulations. Experienced customers always carry out the author's control and often require the use of not colorless compositions, but with a color scheme. Then it is clear whether there is a coating or not. You yourself know that shabashniki are not always scrupulous in this matter.

I can't say anything about other methods. You can, of course, spread out along the rafters, drill holes next to them with a puncher and, driving around on an overhead crane inside the workshop span, push the wire into these holes and twist it. But this is somewhat difficult. Yes, and there may not be a crane, but you can't jump with a ladder.

But this is all speculation on a free topic.

And now what would I personally do if I were you.

In your case, floor slabs are most likely used. If memory serves, with such spans as yours, their dimensions are about 9 meters by 1.5 (or 1.8) meters. The load-bearing reinforcement in such slabs is located along the perimeter. And throughout the entire area there is welded mesh with a large cell. Wire diameter from 3 to 5 millimeters. The plate itself has stiffening ribs. And the thickness fluctuates around 50 millimeters.

The slabs are supported on reinforced concrete arches-trusses. Slab joints along the grooves - lock or simple.

Then it is most advisable not to use logs, as we did with ordinary rectangular flat reinforced concrete floor slabs, but to take for rafters edged board section 40/150 millimeters. Lay it flat on the surface. "40" is more suitable here than "50", it bends better. Laying, respectively, from the edge to its center.

Then the boards of the sheathing can be taken measured, six-meter high and placed along without any bends.

Press the rafter boards well to the surface. That is, fix one end of the board, then a couple of people from the brigade must stand on the other end of the board. It will bend to fit the slope of the roof. Then fasten the next anchor bolt. The step of the fasteners is about 1.5 meters. Drill holes for anchor bolts directly in the boards at their centers. And then drilling in the slabs themselves.

Also drive the anchors with a hammer, screw with a drill with a head. It is most likely impractical to use a screwdriver, its power may not be enough. So that the head of the anchor bolt does not fall into the wood, you can hedge yourself and put a washer under it large diameter... The length of the anchors should be approximately equal to the total thickness of the board, the bitumen layer, plus the thickness of the floor slab.

Along the perimeter of the roof, there should not be many different kinds of holes in order to exclude the so-called windage, when the top wind enters an enclosed space and is able to tear the roof off its base. Such extreme is rare, but it happens.

Everything proposed does not quite fit into SNiPs, they would recommend placing the rafters on the edge for greater rigidity, using a 50/150 board, adjusting its surface along a slope, using an edged board also 50 millimeters thick as a crate. Or remove layers of old roofing material, do concrete screed, or even completely rip off the old floor slabs and install new ones with a new layer soft roof... But your customers are unlikely to pay such costs.

Once again, I repeat that you can have simple reinforced concrete slabs, and maybe floor slabs, respectively, and the mounting options may be different.

Be guided by the circumstances. Try it, experiment.

As for the insulation, there will be no special problems. Isover, ursa, mineral wool, polystyrene, whatever your heart desires. If you observe all the decency, then you need air gaps, various thermal films, at worst, glassine and everything on a counter-lattice. If the insulation is soft and 50 millimeters thick, then it's okay, the "40" board will pass completely, you just need to press down a little.

However, this is my vision. The decision is all the same only for you.

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