vapor barrier attic floor cold attic protects wooden structures ceilings and insulation from getting into them steam from the premises of the house. Steam condensing on the beams can contribute to the damage of wood by fungi and mold, thereby reducing the life of the structure. Condensing in the thickness of the insulation - increases heat loss in the house, because. Water itself is a good conductor of heat. In addition, water, freezing in the thickness of the insulation in the cold season, destroys the polymer bonds of the fibers and reduces the service life of the material.
Cold attic vapor barrier, when using foil materials, in addition to its main function, it allows to reduce heat loss and, accordingly, heating costs due to the creation of a heat-reflecting screen.
Attic vapor barrier materials There are 2 main types on the market:
- Film vapor barrier- does not pass steam (only vapor barrier).
- foil vapor barrier— does not pass steam and reflects thermal radiation (steam and thermal insulation). Such a vapor barrier is mounted with a foil side to the premises.
Vapor barrier of attic floors with foil materials due to its characteristics, it is the most preferred in the construction of a reliable and heat-efficient house made of aerated concrete, brick or monolith.
Vapor barrier for the attic "pie":
- Attic floor (ladders) - necessary for maintenance, repair of the roof and attic space. In order to get into the attic, provide attic stairs with insulated hatch (Thermo). To exit from the attic to the roof, we recommend installing deaf or glazed exit hatches on the roof (Velux, Vilpe, etc.)
- Para- or super-diffusion waterproof membrane - for effective removal steam from the heater.
- Insulation - mineral wool boards. The recommended thickness for the Moscow and Leningrad regions is 300mm. 200mm are laid in the interbeam space, the remaining 100mm are laid perpendicular to the laid layers - counter-warming. For comparison, building codes in Finland determine the thickness of the insulation from 400 to 500 mm. It is recommended to postpone the laying of the insulation as much as possible - not earlier than 6 months after the completion of the construction of the house box. Because for the construction of floors, mainly timber is used natural humidity. The beam must dry properly, otherwise there is a high probability of wood damage by fungi and mold, which entails additional costs for dismantling / installation work and wood treatment with bleaches and antiseptics.
- Control grille and ventilated gap. For effective ventilation and removal of steam from the surface of the moisture barrier membrane.
- Cover beams. As a rule, in private housing construction, a board 50x200mm or a bar of natural moisture 100x200mm is used.
- Crate - the basis for laying insulation. As a crate, it is recommended to use a board 100x20 (25) mm and lay it in 70-80 mm increments. The resulting cracks will form an additional air thermal layer under the insulation. That. slabs (mats) of insulation will not lie on vapor barrier film, but on a rigid base, already under which there will be a vapor barrier. This solution eliminates the possibility of accidental damage to the vapor barrier or its punching when laying insulation, during maintenance and repair work roofs and attics. At the same time, you can start interior decoration premises, and laying the insulation as much as possible to postpone (see above).
- Attic floor vapor barrier wooden beams - fastened with construction stapler from below to draft ceiling(crate), which allows you to cut off pairs from the entire floor structure. It is necessary to overlap the vapor barrier rolls at least 15-20 cm and carefully glue them with aluminum adhesive tape. Be sure to form laps on the walls of 15-20 cm and carefully glue them (start under plaster and other wall decoration). Carefully seal the places where chimneys pass through the attic floor, ventilation pipes and others engineering communications with special sleeves. best material as a vapor barrier polyethylene film high density from 200g/m² and above.
- Close attic - finished ceiling is attached to the vapor barrier. On the crate, guides, the final ceiling is installed (OSB, drywall, etc.). For the best fire protection it is recommended to "sew up" the ceiling with drywall sheets in 2 layers.
Vapor barrier of a cold attic floor (scheme):
Professional opinion: most effective attic floor insulation for the Moscow and Leningrad regions - this is attic insulation mineral plates 300mm thick with foil vapor barrier.
A room in the attic of a private household is used for various purposes: storing temporarily unnecessary things, installing equipment or arranging living rooms. Depending on what the free space under the roof is used for, they choose the method of arranging the attic floor.
What is an attic
The attic space is limited by the slopes of the roof and the ceiling of the residential floor. This place is often used for arranging additional living space.
The attic of private households is of two types:
- Residential. It is called the attic. It can be equipped with a living room, study, bedroom, library, etc. Room height in this case must be at least 220 centimeters. In addition, it is necessary to provide ventilation, natural lighting, and insulate the slopes.
- Non-residential. Such an attic space is usually used to accommodate technical equipment, storage of old or unnecessary things. In this case, a 2-meter height will be enough, and it is not necessary to equip natural lighting. Instead of insulating the slopes, they make the thermal insulation of the attic floor.
When deciding to repair or rebuild a house, you need to decide in advance for what purposes the attic will be used in order to make a calculation and a floor project. This list depends necessary materials and spacing between beams. They must provide the required strength and bearing capacity.
Functional purpose of floors
The design of the attic floor depends on the parameters of the structure and the purposes for which it is planned to use the under-roof space. The function of a kind is assigned to the attic. air gap, which separates cold roof from heated floors.
The floor in the attic performs a number of tasks:
- carrier. The floor, located between the upper living floor and the attic space, is assigned a bearing function, therefore it is made reliable and durable, since people will move along it, they plan to place equipment on it and equip storage places;
- insulating. In a cold attic room, the temperature differs little from that outside the house. In this case, the floors in the attic have a thermally insulating function, thereby preventing air cooling on residential floors. To keep warm, thermal insulation of the attic floor is required. It is advisable to entrust such work to professionals.
Features of the device and the design of floors
Since attic floors perform two functions - load-bearing and insulating, they have a multilayer structure. Each of the elements of the "pie" complements each other, which provides created structure long service life, strength and ability to withstand heavy loads.
The device of the floor in the attic assumes the presence of the following layers:
- Finished floor. This name has been given flooring, which is laid on a rough base. If this is an attic, then when arranging the finishing floor, linoleum, laminate, parquet, etc. are laid. In non-residential premises, the finishing floor covering may be absent.
- Draft base. It is a boardwalk, which is mounted on logs. The subfloor is lined with edged board 4-5 centimeters thick or, in order to save money, from unedged.
- lags. These are strong, smooth wooden elements laid perpendicular to the floor beams to create a floor covering. When the attic floor is being arranged on wooden beams, a heater is placed between the lags, which is protected from below with a layer of vapor barrier, and covered on top waterproofing material. If you do not apply insulating layers, then repairs will be required after a few years.
- beams. The frame of the floors is built from thick and durable beams, which are either mounted on the ledges of the walls or embedded in them. They must support the entire weight of the structure. A flat roof can also be made on wooden beams, which is quite practical.
- ceiling lining. From the side of the overlapping rooms draw up finishing material such as natural wood or drywall.
Types of attic floors
For the device of overlapping a cold attic, materials are used that differ in weight, durability, cost and bearing capacity.
There are several types of floors, depending on what they are made of:
- wooden elements. For their manufacture, beams with a cross section of 150x150 or 200x200 millimeters can be used. The advantage of this option is that the wood is strong enough and at the same time relatively light material, so the wooden elements do not put additional stress on the foundation of the house. In addition, their great advantage can be called a small price and availability. But such an attic floor is used when the size of the building does not exceed 6-10 meters, since this maximum length lumber.
- metal products. I-beams made of metal are durable, able to withstand big weight without deformation. But they weigh decently, so they are rarely used in wooden houses, but for brick and aerated concrete buildings they are the best option.
- Reinforced concrete products. Molded floor beams made from reinforced heavy-duty concrete are used for multi-storey buildings, since they are heavy and of the same length.
Of all the above types of floors in private low-rise housing construction, in most cases, preference is given to wooden beams. They have optimal ratio between price and quality. With well-executed calculations and compliance with the technology, repairs to the ceiling in the coming years will not be required. Ventilation is also needed in the attic of a private house, for the arrangement of which additional knowledge will be required.
Requirements for the device of the pie
Since the safety of staying in the house depends on the quality of installation and repair of attic floors, a number of requirements are imposed on their arrangement.
To know the maximum permissible load that the structure is able to withstand, it is necessary to perform the appropriate calculations, and then, based on their results, they begin to develop a project from which it will be clear how to properly insulate the attic floor in the house.
Requirements apply to:
- Bearing capacity. It directly depends on the material of manufacture of the beams and on the gap between them.
- Distances between bearing elements. The maximum allowable value for this parameter in accordance with building codes equals 4 meters.
- Resistance to temperature changes. It is necessary that the beams can withstand such changes without problems. The fact is that the difference between the air temperature in residential floors and in the attic always exceeds 4 degrees.
- Isolation. The attic floor cake of a cold attic should protect the premises of the household from the penetration of cold and moisture from the under-roof space.
In the design process, the requirements for the beams used to equip the ceiling in the attic should be taken into account so that the result is reliable and durable. The distance between them must be calculated based on the loads exerted on them.
Technology for creating an attic floor on wooden beams
With experience in performing construction works you can mount the ceiling of a cold attic on wooden beams with your own hands. Carry out this process on final stage roofing works.
The sequence of actions will be as follows:
- Mounting bearing beams. For a small private house, wooden floors made of timber with a section of 150x150 or 200x200 millimeters are suitable. They are laid on concrete or brickwork walls.
- Log installation. They are placed on the edge perpendicular to the beams with a step of 60 centimeters. Logs are made of boards with a section of 150x50 millimeters.
- Thermal insulation lining. Insulation is placed between the lags - it will protect against the penetration of cold from the attic.
- Installation of rough and finishing floor.
- Sheathing of load-bearing beams from the side of the room in order to decorate the surface of the ceiling.
When insulating the attic floor, one should not forget about the arrangement of hydro and vapor barriers.
Majority pitched roofs in our country have in their design cold attic. This name is due to the air temperature in the attic, which should not differ much from the air temperature outside the house. With such an arrangement of the attic, a sufficiently large buffer air zone is formed, which allows you to effectively control the temperature in the attic with its proper arrangement.
Cold loft design
When building the roof of a house, many people think about making a cold attic or attic under it? The easiest way to organize a roof with a cold attic. Building an attic will cost several times more and will require more labor costs.. Although, it is undeniable that the attic will significantly expand the living space.
Cold loft roofs have the following main ingredients in their pie:
- roofing;
- attic exterior walls (applicable for gable roofs with gables);
- insulated ceiling between living space and attic.
Ventilation is provided by eaves and ridge ducts. The air passing through the cornice openings is called supply air, and the air exiting through the ridge is called exhaust air. Additionally, you can make ventilation through dormer windows on gables or roof slopes. Windows are equipped with louvered grilles for the possibility of adjusting the intensity of ventilation.
Dormer windows are located on opposite roof slopes so that there are no unventilated areas.
Dormer windows can be rectangular, triangular and semicircular. Them Bottom part should be located at a height of no more than 0.8-1.0 m from the ceiling floor in the attic, and top part no lower than 1.75 m from the floor in the attic. They can also serve as an exit to the roof of the house to inspect the roof, ventilation and chimney elements.
Steam and thermal insulation of a cold attic
For a roof with a cold attic, it is most important to minimize heat loss through the attic floor. For both wooden and reinforced concrete floors vapor barrier is mandatory. It is laid on the ceiling itself and protects the insulation from vapors that can condense in the heat insulator, passing through the ceiling of the living space. As a heater, slab and bulk materials. The ceiling pie consists of a vapor barrier, floor beams and insulation.
The following types of heat insulators are often used in ceiling ceilings:
- polystyrene and foam boards;
- or mats;
- expanded clay granules;
- fuel or granulated slag;
- sawdust with lime or clay;
- pumice.
The thickness of the required insulation layer is selected depending on the calculated winter temperature using the table below.
Winter temperature is calculated according to SNiP 2.01.01-82 (construction climatology and geophysics) or is selected by regions of the Russian Federation from the corresponding climate maps.
Insulation is placed between the joists or beams of the ceiling, and a plank flooring is made on top for attic passages. Logs are usually 50 mm thick, and deck boards are 25-35 mm thick.
For ventilated attic space soft or semi-solid heat-insulating materials are considered the most optimal.
Attic waterproofing device
Waterproofing roofs with a cold attic, according to many experts, controversial issue. Some say that waterproofing must be present under the roofing material, and someone categorically recommends abandoning it. Much depends on the type roofing material and the slope of the roof slopes.
Metal roofs are most susceptible to corrosion that occurs with possible small leaks or from condensation. Therefore, once again we draw your attention to the fact that ventilation plays one of the main roles in the fight against condensate.
For gentle metal roofs experts recommend mandatory installation of superdiffusion membranes. It will prevent moisture from entering the outside of the roof when blowing snow or rain. No matter how well the roof is laid, there is always the possibility of minimal leaks. That is why, by paying a little more, you get additional protection from moisture on the insulation in the ceiling of a cold attic.
Possible leaks or condensate when it gets into hydrophobic heaters significantly reduce their heat-insulating properties.
If, for example, slate is used as a roofing material, then waterproofing can be abandoned. There is also a corrugated board with an anti-condensation coating on the market, which can hold up to 1 liter of water per 1 m 2. For our part, we recommend that you always use waterproofing membranes, because it is the cheapest and easiest additional way protect your roof from possible leaks.
When installing waterproofing membranes, a counter-lattice is used. It performs the function of a fixing rail and, due to its height, provides the necessary clearance for ventilation of the under-roof space. The device of the crate of a cold attic is no different from insulated roofs. The dimensions of the crate and its step determines the type of installed roofing.
There are two types of attic space - a cold attic and a combined attic or attic. In a cold attic, insulation is laid horizontally on the floor of the attic, and the temperature inside the cold attic is about the same as outside.
The temperature inside the cold attic should not exceed 4 °C of the outside air temperature (rules and norms for technical operation housing stock, Decree of September 27, 2003 No. 170, paragraph 3.3.2), i.e. if the temperature outside is -15 °C, then in the attic it should be no more than -11 °C. If this difference is greater, then, for example, at an outdoor temperature of -5 ° C, the slope will heat up, the snow on the roof will melt and drain onto the eaves. The cornice will not heat up, because. there is no under it warm room, and the water on it will turn into ice, forming icicles. How more ice will form on the eaves, the greater the chance of leakage, the higher the load on the roof and the higher the risk of ice breaking, which can lead to tragic consequences. All this reduces the service life of both the roofing and the roof as a whole.
Rice. 1 Cold attic ventilation.
To ensure normal temperature conditions in a cold attic, it is necessary, first of all, to insulate the ceiling between the attic and the living space. The thickness of the insulation is calculated based on several parameters, the main of which is the location of the house. The second most important criterion for observing the temperature regime of the attic space is under-roof ventilation.
In addition to insulation and ventilation, temperature regime of the attic space are affected by: uninsulated manhole covers for access to the attic, the output of ventilation pipes to the attic space (kitchen, bathroom), uninsulated hot water distribution located in the attic, and so on.
roofing cake for a cold attic can be divided into two parts. The first part is on the floor between the attic and the living quarters. The second part is on the slope.
The first part of the roofing pie, depending on the type of flooring, looks like this:
Rice. 2 Pie on a concrete floor.
Rice. 3 Pie on a hardwood floor.
Vapor barrier is used to prevent the entry of moist air from the room into the insulation. By concrete base it is best to use bituminous roll material, with overlay welding. On the logs, a film vapor barrier is used with the obligatory gluing of overlaps with sealing tapes. Use as a vapor barrier vapor barrier films D-Folie B, D-Folie B 90 or D-Folie BR.
The insulation is laid in several layers with a spacing of joints to eliminate cold bridges.
The hydrowindproof membrane protects from a weathering of heat and hit of moisture. Moisture can form due to condensation, due to snow blown into the attic space, as well as due to possible leaks. D-Folie A 150 or D-Folie A 100 superdiffusion membranes must be used as hydrowind protection.
In any case, regardless of the type of overlap, it is not recommended to cover the insulation from above entirely with plywood or boards. If it is necessary to occasionally walk around the attic space, it is better to provide paths from the boards, without covering the entire insulation.
The second part of the roofing pie using shingles in a cold attic looks like this:
Rice. 4 Roof cake for a cold attic.
To maintain a normal temperature and humidity regime in a private house, it is necessary to provide reliable protection from the ingress of cold air. It requires not only thermal protection of the walls and basement floor, but also insulation of the attic floor efficient materials over wooden beams.
Types of attic floors
In a private house, you can apply the following types of horizontal structures:
- precast concrete;
- monolithic reinforced concrete;
- on metal beams;
- over wooden beams.
For construction wooden house most rational decision there will be an option for overlapping on wooden beams. The tree has higher thermal insulation characteristics than concrete, but still the thermal insulation is insufficient.
Warming technology
How to insulate the attic floor so that there are no problems in the future? In the general case, do-it-yourself thermal insulation technology is almost the same. But how to install it depends on the specific situation.
Insulation of the attic floor is carried out in the presence of a cold attic. The thermal protection of the structure is performed from above, since in this case the thermal insulation is the most competent. But in some cases, a different scheme is applied - protection from warm air.
The answers to the question why insulation from the ceiling of the upper floor is undesirable can be the following disadvantages of thermal protection from below:
- the insulation only protects the ceiling, and the ceiling remains cold;
- do-it-yourself work from below is quite laborious;
- the point of condensation is shifted inside the floor pie, which can lead to rotting of the structure along the wooden beams.
It is also important to follow correct order all related materials.
When insulating, you need to remember one rule: the vapor barrier is always located on the side of warm air, and the waterproofing is always on the side of cold air.
Incorrect placement can lead to the following problems:
- wetting of the heater;
- condensation on the ceiling surface;
- rotting of the cold attic ceiling on wooden beams.
Whether vapor barrier and waterproofing are needed depends on the chosen insulation.
The choice of insulation
The methods of insulating the ceiling of the upper floor of the ceiling along the beams in a private house are very diverse. When doing do-it-yourself work, the insulation is placed between the lags and provides reliable thermal insulation and noise protection. There are many options for insulating the structure, the most common of them are:
- mineral wool insulation;
- laying on wooden beams of expanded polystyrene (polystyrene or foam plastic);
- backfilling with expanded clay;
- sawdust insulation;
- filling the ceiling space with foam.
Each of these options has its own characteristics and advantages.
Mineral wool insulation between lags Mineral wool insulation
The material is produced in two versions: plates and rolls. Thermal insulation of the attic floor with mineral wool has the following advantages:
Styrofoam
Styrofoam has become one of the most common materials for thermal insulation. He earned a place in the top three thanks to the very attractive price. The use of this insulation in an individual house provides the following advantages:
- high degree of protection;
- resistance to decay and the occurrence of mold and fungus;
- low degree of water absorption;
- ease of installation and no need for complex tools and protective equipment;
- the light weight of the material does not allow excessive load on the structures and allows for insulation from below.
Extruded polystyrene foam
More often this material is called more short word- penoplex. Being the closest relative of polystyrene, penoplex is devoid of most of its shortcomings. In the process of improvement performance characteristics the cost has increased. The material is produced fireproof, it has sufficient strength to be used as a base for flooring and a small mass for use in the construction of the ceiling.
Do-it-yourself installation is quite simple. This issue is discussed in detail in the article. The text discusses the use of both foam and foam for different types cover structures.
For people who decide to build their own wooden house, usually the naturalness of the materials is important. Here, penoplex, like polystyrene, loses to other types of insulation due to artificial origin.
Expanded clay or sawdust
Warming hardwood floor If you decide to use the house completely natural materials, these two types of insulation will become indispensable helpers. They do not have high heat-shielding characteristics, like the previous types, but provide reliable protection from the cold with a sufficient layer thickness. Sawdust can be obtained almost free of charge, expanded clay is also an inexpensive material.
Insulation of the attic floor can be carried out by non-professionals and does not require special skills. Application restrictions are physical features of these materials: they cannot be used for thermal protection from below.
Foam for thermal protection
polyurethane foam insulation enough new material in construction. At self erection buildings, this method can provide high speed of work and reliable protection from the cold. You can read about the insulation of the building, including attic floors, with foam in the article.
It provides big choice materials for insulation and significantly save on construction.
The insulation of the wooden floor is carried out between the joists, therefore it does not require high strength from the heat-shielding material: the main load from people, furniture and equipment will be taken by boards or timber.
A large percentage of heat loss occurs precisely through the ceiling of the upper floor, so it is so important to choose the right insulation and follow the laying technology.
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