At the moment, in the process of constructing a country residential building, they may be applicable different variants high-quality modern structures for the roofing part of a building or structure. A relatively simple one among them is the cold roof. Such a device is optimally suited in cases where the common attic space is not used as a residential space for some reason.
The design scheme of such a plan is characterized by simplicity; there are elements such as high-quality waterproofing, load-bearing elements and roofing. There are some installation features of this design. They consist in the fact that it is imperative to provide a high-quality ventilation gap designed to remove accumulated condensate.
This is necessary so that carriers structural elements, as well as the roof covering itself, were effectively protected from the adverse effects of moisture.
The installation of such a roof itself is not characterized by any difficulties. The most important thing that needs to be done is to properly fasten all the profiled metal sheets present.
This must be done so that precipitation cannot penetrate through the numerous joints under its surface. Before the beginning construction process, it is worth performing such important steps as:
Compliance with these rules will allow the construction process to be completed quickly and efficiently.
The one described differs from the warm roof in its relative simplicity. The only thing that must be taken into account is the special type of roofing material and its flooring.
When using modern metal tiles, it is recommended to provide an effective ventilation gap that will properly remove condensation from the room located under the roof. This is necessary so that the steel element is not subject to corrosive destructive processes.
The device of this design is the installation of a rafter system; a membrane or high-quality film is mounted on it. Then the counter-lattice, sheathing, as well as the covering, that is, metal tiles, are secured.
The main features of this design include the complete absence of a heat-insulating layer; there are also special ventilation holes, they are located strictly under the ridge and on all slopes without exception.
These devices are used for efficient removal of water. The process of professional design and subsequent installation will not present any difficulties for the master; the most important thing is to correctly carry out all the calculations.
The process itself is qualitative and professional installation consists of such features as:
Important! If such conditions are not met, the roof will not be protected from moisture after some time. In this case, the insulation will always be wet, and the roofing material will be severely damaged by destructive corrosion.
For the installation process of high quality waterproofing membrane It must be remembered that it can be installed with a certain sag of approximately 20 mm. This factor makes it possible to arrange the drainage of drops, which effectively protects rafters and other structural elements of the roof from excess moisture.
In order for water to be eliminated as efficiently as possible and not to stagnate, thereby creating a relatively unfavorable environment, it is imperative to provide a high-quality ventilation hole. It is carried out between the film and the roofing ridge.
Such a gap makes it possible to circulate under the roof without problems, and all traces of moisture and condensation will also be effectively removed.
Important! During the work, it is very important to ensure that the protective membrane does not have ruptures or any other defects, and it is fastened using a special construction stapler. It is mandatory to overlap, that is, all edges of the film must be secured using tape.
Of all the main features inherent in a cold roof, it is worth noting that it is possible to build it, if necessary, for any region of the country. Many people assume that this type of coating may not be suitable for some regions, but in reality this is far from the case.
For a standard living space, having a cold, unheated attic is a traditional solution in all respects.
It is worth noting that the use of a roof of this type will not affect the temperature of the upper floors. The attic space itself may not be used at all, and heat loss is solved by installing a layer of high-quality insulation between the upper floor and a special under-roof space.
In the process of constructing a cold roof, it is worth remembering such a stage of the work as proper insulation of all existing technological exits and openings. These are such structural elements as:
All of them require special thermal insulation. High-quality work will allow you to quickly avoid such unpleasant moments as the appearance of large amounts of condensation, icing, heat loss and the penetration of precipitation.
A device of such a design as a cold roof is one of the most common options due to its simplicity. The roofing pie contains the following layers:
The film, which provides effective protective waterproofing, must be laid with sagging, but other defects are strictly unacceptable. The degree of sagging of the roof covering should be approximately 15-25 mm. This will provide an opportunity to guarantee the highest quality ventilation, as condensate will be removed.
The moisture will first go into the strip on the eaves, and then into the gutter. Neglecting this process will result in moisture completely destroying the roof.
When building a cold roof made of metal tiles, you must remember that a sheet of this material does not provide protection from noise. That’s why no one lives in the attic; it’s cool and noisy there.
To install a cold roof, you need to take relatively simple tools, and Consumables, which can be purchased relatively inexpensively. Special staples are used as the necessary fastening devices; these can be self-tapping screws or galvanized nails.
Important! In the process of calculating sheets of roofing material, you need to remember that you will definitely need additional elements such as valleys, ridge tiles, cornices, and so on.
The design of a standard cold roof differs from an insulated structure precisely in the absence of an insulation layer. Such a roof is erected if the attic will not be used as a living space.
No roofing material is perfect. Even in its main quality - protection from moisture. And in cases where the roof is covered impeccably, and there are no leaks during rain or melting snow, condensation still remains on the inside of the roof.
To protect the rafter system and attic cold roof from condensation, waterproofing is installed as part of the roofing pie. And the fact that it also protects against “small” leaks is a bonus in the form of a time reserve to eliminate roof leaks.
There are not that many roofing materials available. If we consider only, the list will be reduced to several species. And depending on the characteristics of the material itself, the installation technology and the purpose of the building, waterproofing is not always necessary.
Metal roofing can be sheet or piece. Sheet materials are,. Piece covering - roofing checker and roofing scales.
Regardless of the size of the element and the laying technology, the “layering” is the same for everyone:
The presence of waterproofing and a ventilation gap in the under-roof space is also mandatory for heated houses year-round residence, and for unheated cottages or outbuildings.
Any roofing metal has high thermal conductivity and low heat capacity. As the temperature drops daily, the roof cools much faster than the air inside the attic. And it will appear almost every day, even in summer.
In winter, if the building is heated, the air in the attic will be even warmer - any thermal insulation of the ceiling is not absolute. Just like any vapor barrier, it does not provide complete protection against the penetration of warm air vapor into the attic from the room. And there are also chimneys and ventilation ducts, which also serve as a source of heat.
Waterproofing protects the attic and rafter system. And to prevent the counter-lattice and sheathing from getting wet, there must be a ventilation gap in the under-roof space.
Although these materials are different in composition, the likelihood of condensation appearing on their surface is low.
Slate is best in this regard. Its surface texture can be compared to an anti-condensation waterproofing film. A rough surface can retain condensation until conditions for its evaporation and weathering occur. Therefore, waterproofing is not needed for a cold slate roof.
As an example, we can cite Soviet-built apartment buildings - in most “Khrushchev” buildings, slate is laid over lathing without waterproofing. And the only reason the attic gets wet is roof leaks.
Ondulin has almost the same properties. On the manufacturer’s website, as one of the “economy” options for installing a cold roof, a laying diagram without waterproofing is given. And this option is suitable for country houses and summer cottages, summer kitchens and outbuildings.
For houses permanent residence roofing made of slate and ondulin without waterproofing is considered insufficiently reliable. And here it is recommended to lay waterproofing roll materials. standard - the film is attached to the rafters with a slight sag, counter-lattice beams are stuffed on top and.
There are several types of roofing material where this term is present:
Bituminous shingles. Waterproofing is provided at the level of installation technology from the manufacturer. This is one that also serves as an additional fixing element. The bitumen contained in shingles and carpet bakes together when the roof heats up from the sun.
Composite tiles. It's kind of metal tiles with a small leaf size. The differences lie in the composition of the protective and decorative layer. As with any metal roof, waterproofing must be installed underneath it.
Ceramic and cement-sand tiles. They differ from each other in composition, shape, manufacturing technology. But despite this, installation proceeds according to general principles. And the manufacturers of these types of roofing also stipulate the presence of waterproofing when describing them.
There are three types of modern materials:
Superdiffusion membranes. They have good waterproofing properties and high vapor permeability. They are rarely used in cold roofs due to their high cost and excessive “breathing” properties. The main purpose is to protect the insulated roof. It is installed on non-insulated roofs if there are plans for further insulation and the attic is in use.
Diffusion membranes. Good waterproofing properties and average vapor permeability. The optimal choice for slate, ondulin, ceramic and cement-sand tiles.
Water vapor barrier films with anti-condensation surface. This is a universal material that is characterized by high waterproofing properties and limited vapor permeability. Such materials can also be used as a vapor barrier.
Recommended as . They block most of the water vapor in the warm air, which is then ventilated through the eaves and ridge vents of the attic ventilation and through the dormer window.
The waterproofing film is mounted from bottom to top with an overlap of panels of at least 15 cm. The fastening is carried out to the rafters. The film should sag between the rafters, but no more than 2 cm. Additionally, a sealing tape is glued on top, and then a counter-lattice block is nailed.
If it is necessary to increase the length of the canvas, then the joint should be on the rafter leg. Extensions are also done with an overlap of 15 cm.
The superdiffusion film is laid on the ridge without tearing. When installing other types of waterproofing materials in the ridge area, it is necessary to leave a “gap” of about 5 cm on each side.
Sometimes as waterproofing pitched roof roofing felt and its analogues are used. But these materials are designed for waterproofing flat roof over a continuous floor.
IN technological map The TechnoNikol company for the installation of bitumen roll materials indicates that the roofing material is attached to the base using mastics or by fusing.
Mechanical fasteners at large roof slope angles are used as additional “point” fixation to prevent bitumen waterproofing from slipping in hot weather. And this limits the scope of use of roofing felt on pitched roofs.
On those roofs where the slope angles are large and the technology for laying the roof is continuous, lathing is not needed, it is not economically profitable to install it, even though roofing felt is cheaper than waterproofing films. But only mechanical fastening along a row sheathing does not provide sufficient reliability of fixation due to the low tensile strength of roofing material.
If you do not plan to make a living room in the attic, you can leave the attic cold - store some things here, set up a workshop, hayloft, etc. There is no need to insulate the roof. How is a cold roof made of soft tiles, are there any special features?
The basic rule for cold attics does not depend on the covering: a full-fledged cake is made in the attic floor, otherwise the house will be cold.
Otherwise, the cake is made according to all the rules: vapor barrier, waterproofing, and the floor is covered with boards on top.
The second feature concerns ventilation. Here the differences in materials are already affecting. For soft roofs (as opposed to profile metal) there are no waves that would serve as ventilation. The bitumen coating is completely sealed and does not breathe.
Otherwise, the technology of a cold roof made of soft tiles differs from that of an insulated one: on cold roofs, a continuous sheathing can be laid directly on the rafters (without counter beams). The entire attic serves as a ventilation gap. The sheathing and rafters are not covered from the inside.
When installing a cold roof, additional measures are taken to ventilate the attic:
More about ventilation soft roof I already wrote in one of the articles. You can get to know her.
Due to the absence of a pie, it is easier to make a cold roof than a warm one:
1. Lay a continuous sheathing of plywood or OSB on the rafters. The slabs must be laid with joints spaced apart. The joints should be at rafter legs. There is a technological gap of 3 mm between adjacent slabs/sheets. Fastening with self-tapping screws or nails.
2. Underlayment: On low-slope roofs, the entire roof area should be covered.
3. Install cornice drip strips over the edge of the carpet. Fix with nails in a zigzag pattern every 10 cm.
4. Install the end strips in the same way.
5. In the valleys, lay on top of the lining. Fix the edges with nails every 20 cm.
6. The tiles are laid in rows from the eaves to the ridge. Installation of tiles on gable roofs begins from the end, on hip roofs - from the middle of the overhang.
7. Lay on top of the plank with a distance of 3-5 cm from the edge. Place it on glue (or on a self-adhesive layer) and fix it with nails. The joints of the cornice strips must be covered with petals.
8. The next rows are placed so that the petals overlap the attachment points of the previous ones.
9. In the valleys and at the ends, the tiles are cut and placed on glue. Fixation with nails.
The Internet and all kinds of thematic printed publications are full of advertisements for the construction of a turnkey dacha. As a rule, the proposal specifies the installation of a roof with “ roofing pie"and describes the advantages of some kind of insulation. But a natural question arises: is it always necessary to insulate the roof?
Does it make sense to insulate an outbuilding, say a barn, or spend money on insulating a non-residential attic? Maybe, after all, it’s enough to limit ourselves to insulating the floors last floor under the attic? But the consumption in the latter case will be significantly less, since the treated area is significantly smaller than the roof area.
Obviously, for some types of buildings there is absolutely no need for roof insulation.
In what cases is it better to have a cold roof, and how to arrange it in the best way?
Cold roofing is usually constructed for two reasons:
Construction specialists consider insulation baseless attic space, if the house under construction does not have an attic. IN equally this can also be applied to outbuildings.
It should be noted that the installation of a cold roof , does not mean at all that there is no need for ventilation of the under-roof space - it must be present in any house or building. This can be done by installing a double roof or using dormer windows.
Cold roof has a fairly simple design.
On inner surface metal roofs quite often experience condensation, which negatively affects the attic space. To protect yourself from it, it is enough to lay a film or waterproofing membrane on the rafters
Water vapor is removed from the under-roof space through special ventilation outlets under the ridge and on the slopes. As for the attic space, it is additionally ventilated through the existing dormer windows.
Thanks to the simplicity of the design, the process of designing, installing and operating a cold roof is greatly simplified.
The design of a cold roof and the materials used have some features. For example, you need to carefully select waterproofing materials. Usually for cold roofing they use micro-perforated roofing, which, by the way, is quite affordable. It is mounted with a sag of 20 mm, which allows water, which seeps through the film due to the capillary effect, to flow freely to the middle of the run and not wet the rafters. To allow air to escape unhindered, a gap is made in the waterproofing under the ridge.
However, it is impossible to mount insulation closely to such a film. The fact is that when it comes into contact with the insulation, the film loses its insulating properties and the insulation actually gets wet. So, if you plan to equip an attic in the future, it is better to use a waterproofing membrane.
When installing a cold roof, you can use all traditional materials as a covering, which do not require a solid base. However, the optimal solution, according to experts, is profiled sheets or metal tiles, which are technologically advanced, durable and reliable roofing materials.
Steel profiled sheet
The simplest solution for a cold roof in the case of a non-residential building is the use of profiled steel sheets equipped with an anti-condensation coating. This material, which has the structure of synthetic felt, is applied to reverse side profiled sheet directly during the manufacturing process.
Between the interwoven fibers of synthetic felt there are many tiny air cavities, due to which the coating accumulates and retains a certain amount of moisture (up to 1 l/sq.m.). As the air temperature rises, it begins to evaporate intensely. In this case, there is virtually no need to install a counter-lattice or lay a waterproofing film.
Installation of a roof made of profiled sheets with an anti-condensation coating is carried out similarly to the installation of conventional corrugated sheets. For installation work, neither specialized tools nor additional devices are needed. When using this material, a 30% cost savings is achieved according to the estimate.
The anti-condensation coating reduces the noise of wind, hail and rain, prevents the formation of mold and mildew, and is easily cleaned under pressure using water to remove contaminants.
