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Pros and cons of flat roofing

In the process of deciding on the construction of this type of roof, it is necessary to consider the advantages and disadvantages of the future structure.

The advantages include:

• Effective protection against negative environmental influences;
• Exclusive, original look;
• Low cost, effort in the construction process;
• Long-term operation with no huge costs for its care;
• The possibility of obtaining additional space, where, if desired and financially possible, you can even design a pool;
• Remarkable characteristics of heat and waterproofing.
• Maintenance, checks of important structural components are much easier to carry out than with a pitched roof;
• Snow that accumulates in winter provides additional thermal insulation, so that a house with this type of roof can be heated less.

Flat roofs, however, have a number of significant disadvantages:

• Careless waterproofing work threatens to leak the ceiling of the house when water accumulates, melting snow, ice;
• The internal drain runs the risk of freezing, clogging with debris;
• The outer layer needs to be cleaned of rotted foliage, snow drifts. And all this will have to be cleaned only by hand;
• Roofing materials of sheet, piece type are not available for use;
• The technical condition of the insulation cannot be checked.
• The waterproofing system is subjected to stress when snow melts, puddles and ice form on the surface of the roof.

Many who have a straight roof have an ambiguous attitude towards the attic floor, which is absent in this design. Both positive and negative. Depending on preference. Therefore, it is very important to consider coverage options before proceeding directly to roofing.

Classification

For a fairly simple design of a flat roof system, special skills are not needed during the design process. According to its characteristic features, it is customary to classify it into the following types.

Operating type of roof. During installation, an integral waterproofing layer is preserved, sufficient rigidity of the base is achieved. The insulation must be durable, resistant to stress. Covering — paving slabs.

Unused type. Protection from negative environmental factors. It is much easier to set up, simpler, since there are no specific requirements for the rigidity of the foundation and thermal insulation. It can be a lightweight subtype, with more loyal requirements in terms of construction, when external weather conditions do not put a significant load on the roof.

Roof of classical type. Additional moisture protection of the insulation is carried out by laying the heat-insulating layer on the foundation of the structure. Bituminous material is used for waterproofing.

Roof of inversion type. It has a structure, as if a mirror-like roof of the classical type. The waterproofing layer is located under the insulation, and not above it, as was intended in the previous design. The temperature difference from which the waterproofing is destroyed is minimal.

Lawn type. Purely decorative, with a layer of soil over the base of a flat roof, when the space on the roof is used as a flower garden or simply greened with climbing, creeping plants.

You can also find flat roofs of a combined type, when green grass surrounds, for example, a summer cafe located on the roof of a house.

To effectively combat precipitation, there are 2 features in the design of the roof:

• Internal drainage, to protect thermal insulation from moisture;
• Water discharge due to a natural feature, a flat roof — a slope.

Design

At this stage, all the necessary calculations are made, the necessary design parameters, dimensions, amount of material used, and its cost are determined. Each stage of work is considered in detail. A detailed action plan is being drawn up.

Regardless of the number of storeys of the house, the design of modern flat roofs has its own characteristics:

A roof of this type can be called flat only conditionally, since there is still a slight slope (up to fifteen degrees) so that atmospheric precipitation does not accumulate.

The roof of a flat exploited type, while maintaining its geometry, must be sloped to be able to drain water from its surface, maintain the integrity of the waterproofing layer, and remove increased static and dynamic loads from it.

Step-by-step design is carried out in the following sequence:

• In the form of a sketch, a rough sketch of the future design is made — geometry, dimensions. The load that will act on the frame of the structure together with atmospheric influences is calculated.
• The truss structure is calculated in detail (sectional area of ​​\u200b\u200bthe support beams, a step in the design of the lattice).
• The design of ventilation and drainage is being considered.
• Taking into account all the measurements, the final drawings-diagrams of the roof with all its elements are made.
• An estimate is drawn up, which includes both the cost of building materials and the cost of carrying out the work.

At the same time, it is better not to chase the scenery, pay more attention to the functionality of the future structure. It is important to note that one-story type houses with a flat roof cannot be used when a lightweight roof is used in the construction process!

Flat roof construction process

When atmospheric precipitation falls in small quantities, it is possible to construct a lightweight roof. In fact, its construction resembles the erection of a classic flat structure, only in a lightweight form with a number of specific features:

• Support beams are attached to load-bearing walls with through anchors. The whole structure rests on them.
• When choosing supports, their cross section is calculated according to the maximum snow load.
• Solid sheathing, laid without gaps from boards 25 mm thick.
• Fastening layers of waterproofing over the crate using construction tape or special glue.
• Flooring of solid thermal insulation over waterproofing using mounting foam for sealing joints.
• Creation of ventilation ducts to avoid the accumulation of moisture inside the thermal insulation materials, impregnation with it.
• Laying the top layer of the «roofing cake».
• If it is planned to breed a green lawn, then an additional water-repellent layer is laid on which, in fact, the soil will be poured.

Razklonka is carried out in the process of mounting the base using a cement screed, or in the process of laying the insulation, manipulating its thickness.

In modern houses, when designing an exploitable flat roof, it is assumed that the roof, under the influence of external loads, will retain its external shape, without deflections.

There are certain requirements for the design of the foundation of such structures, which are recommended to be strictly observed. In particular, the following methods are used to achieve the necessary rigidity of the base:

• Concrete slabs are used for the floor. In this case, the strength of the load-bearing walls must be with a sufficient margin so that the entire structure does not collapse!
• The use of channels. T-beams, I-beams are also used. A solid wooden crate is made on top of them.
• Ceramic building blocks laid on support beams additionally provide good thermal, hydro and sound insulation. The high cost is their only drawback!

When building a roof, you need to understand that its life depends on the quality of waterproofing work.

Looking at catalogs of cottages with a flat roof, you can be pleasantly surprised at the variety of existing architectural projects. Definitely, they are different from the eyes of the towers and tents, which are sore on the eyes. The lightness of the perception of such houses favorably emphasizes their exclusivity.

With modern technologies, private houses with a flat roof become an ornament, a demonstration of refined taste, favorably distinguishing them from other similar, already pretty boring «houses».

Photo of houses with a flat roof