A house with a flat roof: design features, pros and cons
There are many options for designing a roof for a private house. Today, along with tent structures, modern technologies and materials make it possible to create flat variants. It is worth considering in more detail what constitutes a house with a flat roof, its design features, pros and cons.
Traditionally, in temperate and northern latitudes, a hip roof with sloping slopes was erected, which prevented the accumulation of snow on the surface of the snow cover and allowed abundant rainfall to flow down to the rainfall system. Houses with a flat roof were common in the southern regions, where there was no heavy rain, and snow did not fall out at all in the winter. But the development of building technologies and the emergence of modern materials, especially waterproofing, made it possible without problems to create a horizontal roof in any regions, even in the conditions of the Far North.
Flat roof - this is the overlap, which is located horizontally directly above the residential floors of a private house. Several layers of insulating materials that protect against moisture, cold and steam, as well as a system of drainage systems allow you to create reliable upper protection in a one, two or three-story private house.
Do not be afraid that there will be leaks on the ceiling of the last floor, as with the right approach and high-quality materials, they are completely excluded. The main thing is to properly operate such a roof and timely change the coverage according to the warranty period.
For buildings with a straight roof, the functionality increases, since the surface of the roof can be used. In many ways, the installation of such constructions is simplified compared to the tent options, where the truss system must be erected. They have a lot of other advantages.
Principle and types of construction
For a start it is worth noting that the flat roof in a private house is not strictly horizontal, in order to avoid water accumulation and its drainage, a surface slope of about 5-7 ° is provided. The principle here is the samelike the sloped roof weirs - they are located under a slight slope, which is invisible from the ground, but allows all the accumulated moisture to drain into the drainpipe. Also on a flat roof: water collects in a certain place due to the unevenness of the surface, but the platform looks horizontal, you can safely break the lawn on it or equip the area for rest.
Drainage system on a similar roof contains special funnels.into which rainwater flows under the action of gravity and then with the help of a hose system goes down the drain or underground. These devices are made of plastic that is not exposed to moisture and rotting, mounted in insulation layers on the roof, and are supplied with a protective mesh on top, so that the neck and drainage system do not clog. One such water intake funnel is designed for approximately 100-150 square meters. m of roof area, from here you can calculate their total number. Usually for a small country house is enough 1-2 pieces.
Flat roof can be exploited and unexploited. If it is practically not used, that is, it is lifted several times a year to check the integrity and maintenance, the coating contains the following layers from the bottom up: thermal insulation, vapor barrier and waterproofing.The technology of flooring here is almost the same as in residential apartment and industrial buildings.
The following common types of unexploited flat roofs exist: corrugated and monolith.
- The first option - frame. First, a sheathing of metal profiles or wooden bars is mounted on the concrete base, insulating materials are placed into it. Then, metal sheets are attached to the frame. This is a relatively cheap option, easy to install, the design is lightweight. But to walk on such a roof is almost impossible, because the profiles will sag and deform.
- Monolithic coating for a flat roof contains several layers. A vapor barrier film of hot bitumen is laid directly onto the concrete slab, then mineral wool and waterproofing is applied, and a cement-based screed reinforced with reinforced mesh is poured in from above. Such an unexploited roof will have a lot of weight, but it will reliably protect the house from precipitation and cold.
Another option is if the roof is constantly involved, people walk on it, there are some objects.Then the insulating layer changes in order: first, there is a waterproofing over which thermal insulation is installed. Therefore, this roof is called inversion.
The order of flooring materials is as follows: First, a bitumen-polymer membrane is placed on the floor slab, then a layer of thermal insulation made of penofola, polystyrene foam or expanded polystyrene is placed. If there is a desire to create a green lawn on the roof of your house, then a separating and filtering layer of geotextile will be laid over these insulators, and then a fertile layer on which natural grass will grow.
Such a roof with a fertile layer can be used freely throughout the warm period, with a properly installed drainage system it is not afraid of rain. On the roof, you can place a children's or sports ground, put up sun beds or benches, break up flowerbeds and even have a picnic. Operable green-coated roofs today are common not only in summer cottages, but also in urban homes.
The arrangement of a flat roof does not end with the laying and pouring of insulating layers and laying of drainage systems. For proper operation, it is necessary to create ventilation.Moisture and its vapors can accumulate between the layers of insulation, later on during frosts the insulating cake can crack, bubbles appear on it, detachment occurs. In order to avoid this, use aerators - plastic or metal tubes with caps in the form of an umbrella, which are mounted inside the roof covering. The air entering through them due to the pressure difference weals the water vapor from the insulation layers, they remain completely dry.
Another important point after the flat roofing is the construction of lightning protection. It should not be neglected, because, despite the low probability of occurrence, a thunderstorm can lead to the most disastrous consequences in a country house. A lightning-receiving grid is installed inside the insulation layers, if they are not combustible, or if they are combustible, on top of them on special holders at a height of 10-12 cm from the surface. All nodes of this grid are connected in one lightning rod of thick conductive wire that goes to ground.
Advantages and disadvantages
Low-rise buildings with a flat roof, built according to various projects, have been exploited in our country for more than a year.Reviews of the owners, who have lived in such houses for several years, will help to highlight all the advantages and disadvantages of such structures.
They have the following advantages:
- saving materials - no need to build a complicated roof system, and roofing work is simplified;
- the speed of construction compared to dual-slope and especially hip roofs;
- convenience of repair and change of roofing;
- the device of a flat roof allows to make a platform on it for various needs: a lawn, a recreation area with a gazebo, a gym, a children's corner, etc .;
- it is possible to install windows in the ceiling; this is a very original interior design plus an additional source of natural light on the ceiling;
- roofing work will be much safer than in the case of a hipped roof;
- with strong gusts of wind there is no risk of disruption of massive trusses and cladding.
According to reviews of the owners of such houses, you can also point out the disadvantages of a flat roof:
- unlike tent structures, on such roofs in the winter snow will accumulate in large volumes, which must be regularly cleaned by hand;
- installation of a drain system is required;
- you will need to constantly monitor the integrity of the roof, no leakage;
- despite the apparent ease of installation, flat roofing has a lot of nuances, insulator layers and gutters must be made as correctly as possible, otherwise leakage cannot be avoided.
Many projects of private houses with a horizontal roof came from Europe, where the climate is milder. Therefore, such decisions need to be adjusted in accordance with our more severe weather conditions.
What to do?
Flat roof can be made of various materials, their choice depends on the building structure itself.
- If the house is brick, gas silicate or concrete blocks, then a slab of reinforced concrete can be used as a roof covering. In this case, the roof will be as strong as possible, you can place bulky and heavy objects on it. Such overlapping material does not have protection from moisture, so in any case, you will have to make a waterproofing layer of bitumen rolled or screed with a lower bitumen-polymer membrane.
- Wooden roofing floors of similar design will cost less than concrete, they can be made on a country site itself.A frame with beams is installed on the walls, you can take 10x4 cm or other planed bars as others, as long as they are able to bear the weight of future insulation and other objects located on the roof. The wood is treated with antiseptic and fireproof solution. Roof of timber can be covered with wood-based panels, board or metal sheeting.
- As a waterproofing for houses with a flat roof, bitumen is traditionally used. This organic material based on hydrocarbon, which is produced during the distillation of petroleum. It has excellent waterproofing properties, is not affected by moisture, rotting, is not afraid of frost. The main disadvantage of bitumen is considered to be its non-environmental friendliness - it contains harmful components; when heated, it emits a sharp odor. Nevertheless, bitumen insulation is still in demand, including in the construction of houses with a flat roof.
Bitumen can be rolled and liquid. Usually, for maximum efficiency, a combination of these two types is used. First, the hot solution is poured onto the prepared cleaned surface, then rolls of solid bitumen are rolled up.This combination allows you to close any microscopic cracks and cracks and reliably protects the roof from moisture.
- There are other modern waterproofing materials that are cleaner and more harmless than bitumen. These include, for example, euroruberoid. It is also made on a bitumen basis, but, thanks to synthetic fabrics and polymers in its composition, it emits less harmful substances and odors. Euroruberoid is available in rolls, for strength, it is sprinkled with special mineral chips.
- There is sprayed waterproofing for the roof in the form of powders and aerosols. It is applied to the surface with the help of special equipment. Such mixtures are produced from plasticizers, cement, synthetic resins and hardeners. Their advantages are that they not only protect from moisture, but also reflect the sun's rays, do not let in steam.
- To protect against precipitation is widely used coating waterproofing. She, like liquid roofing material, is applied to the roof surface with a roller or brush. Among such materials, emulsion, rubber, polymer mastics and primers are particularly common.
- There are options for bulk waterproofing in the form of granules, which absorb moisture well and do not allow it to leak into the living room. Examples are expanded clay and crushed stone.Their advantage is that it does not require complex installation - the granules just rise to the level of the roof, crumble and evenly smoothed over the surface.
- As a vapor barrier, a polyethylene film with a thickness of 0.1–0.5 mm is usually used, which is laid over the entire width of the roof under the insulating layer. To protect against the cold, a lot of effective materials are used: mineral wool, foam plastic, polystyrene foam, polystyrene foam and others.
- Very spectacular and impressive in appearance are solid glass roofs. The transparent ceiling in the house visually increases the space, creates a unique air atmosphere, it is always as light as possible in the rooms. It is not very difficult to mount such floors, it is enough to create a frame of metal profiles or wooden frames and glaze it. But the operation of the glass roof is complicated, in the winter it is necessary to constantly clean it from the snow cover. Therefore, it is best to make a solid ceiling with small skylights.
Flat roof can be installed in a one-two-story house with a small area, and in a spacious cottage.In a large building, you can combine a pitched hipped roof with a horizontal one, for example, using it for an outbuilding or veranda. The shape of the roof can also be different: square, rectangular and more complex. The main thing with a non-standard project is to correctly calculate the slopes and the system of spillways so that moisture does not accumulate on the surface.
On the inversion flat roof can be located air conditioners, ventilation systems, television antennas, communication boxes and other equipment. If the roof will be used as a platform for recreation or other active pastime, then it is necessary to install a fence along its edges.
Also at installation of a similar roof at once it is worth taking care of convenient raising upward with a handrail. There are many projects used inversion roof with drawings that can be guided in the construction of their home.
Before construction and arrangement of a flat roof it is worth breaking step by step the plan of all works.
- It begins with the choice of form, type and materials for the floor. It should be borne in mind that the load on such a design is always more intense,than on tent options. Based on this, you need to make a drawing of the frame system with beams and ceilings. The sketch indicates the geometric shapes, sizes, colors, materials, necessary communications. It’s best to have a visual idea of what the future roof will look like for your home.
- Then you need to make a choice of future insulation coating. It should be guided by the existing climate, the characteristics of the overlap of the upper floor, the appointment of the roof - it will be exploited or not. Preferences should be given to modern polymeric materials, rolled or sprayed. They must have high insulating characteristics, at the same time be harmless.
- If you have to make a frame roof, the installation of the batten begins with the preparation of the rails, their sawing. All preparatory work: polishing, coating with protective varnishes, marking and cutting should be carried out on the ground, in a specially equipped area. For lifting fragments of the frame and mounting on the roof, it is imperative to use solid and fixed scaffolding with wide platforms. Works should be carried out in clear and dry weather.
- Next on the frame set overlap and mount the insulating cake. Before covering with insulating layers, it is necessary to install a drainage system with funnels and discharge hoses, provide ventilation openings and aerators, and a lightning conductor system. To achieve maximum protection of the roof from moisture, it is necessary to ensure the tightness of all joints and connections. They must be further treated with mastic, sealant or insulating tape.
After all the protective layers are installed, the roof can be equipped in accordance with its project: make fences and railings, pour the fertile layer and plant green spaces, put furniture and other items.
The installation of a flat roof is quite possible to do it yourself, having scaffolding, the necessary materials and a set of available tools: a hacksaw, hammer, drill, tape measure, level and assembly knife.
Examples of spectacular design
Flat roof in a private house can be represented in various ways. Some examples, created by yourself at a country site, should be considered in more detail.
Non-exploited flat roof in a one-story extension of a private house.Effective insulation materials allowed us to create a simple and elegant design of irregular shape. The shiny surface well reflects the sun's rays, and during rain the moisture does not accumulate on the roof.
The roof of the high-tech building is very spacious and has an unusual shape. The site is not used for a recreation area; only solar panels are located on it. If necessary, you can put on it and other devices and communications.
Flat roof terrace over the garage. The project is interesting because you can enter the upper platform directly from the living room on the second floor of a country house.
Modern technologies even make it possible to create a pool on the roof of a country one or two-story house. It is not as difficult as it seems: it is enough to pick up effective waterproofing materials, install a floor that can withstand the weight of a bowl with water, and build a drainage system. But such a project will be really impressive.
A country house with a flat roof will become much more comfortable if you break a full lawn on it. Insulating materials and the fertile layer are not very expensive, and the result will be a wonderful recreation area.
How to mount a flat roof, see the following video.