Roof insulation on a roll base. Flat operated roof: device, structure. Features of the structure of the roof

How and with what materials can the attic and the roof be insulated? Is it possible to insulate the roof from the outside? We will try to answer these and many other questions within the framework of the article.

Overlap or roof

Let's start with the main thing: first, we need to decide what exactly is to be insulated. Whether to build a cake of waterproofing and insulation on the roof or insulate the ceiling?

The answer is ridiculously simple. If the attic room is planned to be used as a residential attic, the roof is insulated. If the attic is used only for storing rarely used things, the obvious choice is to insulate the floor between the residential part of the house and the attic.

Causes?

The area of insulation in this case will be much smaller. If so, our costs will also decrease.
It is immeasurably easier to insulate the ceiling than the roof. The thermal insulation material can be simply laid on a horizontal surface: there will be no problems with its fixation.

Useful: the attic can be summer, used only in the warm season. And in this case, it is wiser to insulate the floor.

Insulation of a flat roof stands apart. In this case, there is no particular choice: we will not only have to insulate the roof, but also provide reliable waterproofing with rainwater drainage.

Insulation schemes and materials used

Flat roof

It is with her that we will begin our review of possible schemes.

Polyurethane foam

Roof insulation with foam implies the use of an industrial installation for spraying the components. Excellent adhesion of polyurethane foam allows you to insulate the roof with minimal preparation: you just need to thoroughly clean the surface of debris.

Thanks to the ability to apply a layer of variable thickness, an experienced operator can combine the insulation of a flat roof with the alignment of the recesses and the creation of the slope necessary for the water to drain.

High density foam is used for roofs - 60-80 kg / m3. This material is non-combustible and has excellent waterproofing properties as a pleasant addition; however, additional water protection will be required. As a rule, a reinforced screed is poured over the insulation, on which additional waterproofing is laid - liquid rubber or, much cheaper, roofing material on bitumen mastic.

The material is very practical and durable; its main drawback is its high price.

Expanded polystyrene, polystyrene

The material has a solid load; however, it is distributed evenly over its entire surface thanks to the screed lying on top. The use of extruded polystyrene foam or C-35 foam is recommended.

The material allows you to easily carry out roof insulation with your own hands. On a surface cleaned of debris, sheets of insulation are laid out with minimal gaps; in order to avoid the appearance of cold bridges, the seams are foamed. The screed laid on top ensures the slope of the roof (creating a slope for water drainage).

With the use of extruded polystyrene foam, it is possible to create a so-called inversion roof: the insulation is placed not under the waterproofing, but on it. A layer of drainage or even soil may be present on top. The inversion scheme is typical for an exploited roof (see also the article).

Mineral wool

The method of application is completely identical to the previous material (Read also the article).

There are also several nuances associated with mineral wool:

Only glued insulation in the form of slabs is used.
The thicker side of the slab should be facing up.
The material is hygroscopic. Correct insulation with its use includes a layer of waterproofing between the mineral wool and the screed. In addition, a vapor barrier layer is laid under the slabs on a concrete base or profiled sheet.

Floor insulation

Now let's look at ways to insulate the floor between the residential part of the house and the unused attic.

Expanded clay, slag, sawdust

Warming with expanded clay on a concrete floor is one of the cheapest. However, it will be quite time consuming: it is not easy to drag a few cubic meters of material into the attic.

Actually, in the case of a monolithic or slab reinforced concrete floor, no additional measures for vapor barrier or insulation protection are required: expanded clay or slag is covered with a continuous layer. Thickness - at least 25 centimeters.

If the floor is wooden, a slightly more complex scheme is used.

A plank board is sewn up along the beams from below.
A vapor barrier film is laid on it.
The insulation is filled in to the full thickness of the beams.

Mineral wool

In this case, the instructions are a little more complicated: mineral wool slabs fill the space between the beams and are separated from the surrounding air by two layers of vapor barrier - from the bottom and from the top.

Expanded polystyrene

Its use is most meaningful if you want to turn the attic into a summer attic.

One simple solution looks like this:

Plates of extruded polystyrene foam with a thickness of 2-3 centimeters are laid out on a flat floor surface. Concrete does not require any gasket between it and the insulation; it is best to lay penofol on a wooden surface with a reflective layer down. The seams are glued.
The flooring is laid on top - plywood, OSB or chipboard plates in two layers with overlapping seams. In this case, the floor will not play underfoot. The layers are fastened with short screws with a pitch of no more than 25 centimeters.
Linoleum is spread along the flooring or a laminate is laid on a substrate.

Useful: the loggia or cold floor on the first floor can be insulated in the same way.

Pitched roof

Well, what does the insulation of the second floor look like under the roof? Obviously, in the case of an attic, we will have to use the space between the rafters for insulation.

In all cases, waterproofing must be present under the roof. The film is fixed with a stapler at the stage of roof installation: it is laid in horizontal stripes, starting from the bottom. It is necessary that the inevitable condensate on a roof made of metal or profiled sheet does not get into the insulation.

Then the actual roofing material is laid along the crate. For slate and metal tiles, a lathing made of a bar with a cross section of at least 25 mm is recommended; for all types of soft roofing (bituminous tiles, roofing material, etc.), the assembly of a solid board is required.

Any insulation made of hygroscopic material is protected from the inside with a vapor barrier film with mandatory gluing of the seams.

How can roof insulation be performed?

Polyurethane foam is also used for roof insulation. The space between the rafters is foaming; in this case, there is no need for a vapor barrier.
Cellulose-based can be sprayed in a similar way. When laid wet, it also forms a continuous layer of thermal insulation between the rafters.
The technology of roof insulation using mineral wool slabs is simple and unpretentious: the slabs are inserted between the rafters. For additional fixation, you can use a cord stretched between nails driven into the side surfaces of the rafters.

Attention: in this case, the vapor barrier should be insulated with special attention. Mineral wool is hygroscopic, and its thermal insulation properties are highly dependent on the moisture content of the material.

Foam plates are also inserted between the rafters; the seams are foamed. The calculation of the required thickness of this insulation for each climatic zone can be found in SNiP II-3-79 “Construction heat engineering”.

Finally, extruded polystyrene foam can also be used to insulate the roof from the outside. It is glued onto a solid board - board or plywood; then it is protected by waterproofing - roofing felt with gluing of the seams with bitumen mastic. Of course, the use of a burner in this case is unacceptable: the material is not heat-resistant.

Conclusion

As you can see, roof insulation with your own hands and using industrial equipment is possible at any stage of construction. In the video presented in this article, you will find additional information on this topic.

Insulation of any roof, including a flat one, is considered an effective method that allows you to significantly reduce heat loss. Moreover, a significant effect is achieved with fairly modest heating costs. And this is not the only benefit that thermal insulation provides. But how to correctly choose insulation for a flat roof and lay it.

Nuances of flat roof insulation

The principles of thermal insulation of a flat roof are fundamentally different from the approach to the insulation of pitched options. The flat structure does not have rafters between which an insulating layer could be placed. There is nothing to fill the crate with, therefore, the formation of ventilation gaps of the components of the roofing pie, as in pitched roofs, is impossible. The analogy can be traced, perhaps, only in the order of the layers. It includes the following components:

Vapor barrier. The layer is laid from the side of the premises and blocks the path of household vapors.
Thermal insulation. It is a barrier to the passage of heat from the inside of the house to the outside and vice versa. In parallel, it plays the role of sound insulation.
... It protects the external insulation layer from atmospheric precipitation.
Finish coating. For ballast roofs, a layer of waterproofing is covered with gravel, or paving slabs or a layer of soil under vegetation are laid on top of it, and more.

If the sequence of laying the layers is violated, as well as the rules of the device, deplorable complications arise that force the owners to spend impressive sums for repair work, and sometimes for capital reconstruction of the roof.

However, it should be noted that the need for such a design arises only if it is necessary to ensure the efficiency of heating, that is, to keep heat in them. So, if we are talking about the roof of a summer kitchen or ancillary buildings, there is no point in insulating a flat roof.

In such cases, proceed, for example, as follows:

in the concrete roofing cake, only waterproofing is present:
on the corrugated board - prefabricated screed and waterproofing,

Classification of thermal insulation of flat roofs

Attic. There are two types of structures: attic floor with a lightweight superstructure or separate superstructure and floor structures. If in the first case only the floor is insulated, then in the second - the floor or superstructure.

Attic structures can be easily inspected so that future leaks can be identified in a timely manner. The roofing cake can be dried by simply ventilating the attic. We especially note that insulation can be performed on an already finished roof. The construction of an attic structure costs an impressive amount, but a long operational period and a rare need fully pay off.

Insulation for a flat roof: technical nuances

For insulation of a flat roof, almost any material is used that is suitable for thermal insulation of floors and walls. The following are especially in demand:

On a note

Wedge-shaped insulation cannot be considered as a worthy replacement for the thermal insulation layer. Wedge-shaped slabs solve exclusively drainage issues.

The choice of the method of installation of thermal insulation

The method of thermal insulation, as well as the characteristics of the required material, depends on the type of base:

Reinforced concrete. Insulating material, most often mineral wool, is chosen with a compressive strength of 40 kPa or more. In this case, the deformation parameters should not exceed 10%. A cement-sand reinforced or prefabricated screed is poured over the layer of thermal insulation.
Decking. The insulation system has a two-layer structure. The lower tier with strength indicators of 30 kPa or more is laid on the tops of the profiled sheet. For the upper tier, this parameter should not be less than 60 kPa. Possible deformation is within 10%. When installing a roof, the covering is laid directly on the insulation system.

The insulation should rest on the flat part of the corrugated board for at least 30% of its own area. Therefore, if the thickness of the thermal insulation board is twice the distance between the corrugations, the thermal insulation can be laid directly on the galvanized base. Otherwise, a preparatory leveling layer of CBPB boards or flat slate is required.

How to lay insulation

To place a hard insulation for the roof on a flat roof, start from the lowered roof area, more precisely from its corner. If, for some reason, the slope of the structure during construction work was not observed, then you need to start from the places where the gutter is installed either.
Heat-insulating plates are placed on the profiled sheets in such a way that the corrugations and their long sides are mutually perpendicular. In this case, the attachment can be carried out through different ridges.
Plates in multi-layer thermal insulation are arranged according to the principle of brickwork, that is, the joints are spaced. In addition, the lines of joints and crosshairs in the upper tier cannot coincide with those in the lower row.

Below is one of the options for cutting and laying insulation.

Mounting options

To fix a layer of insulation on a flat roof, the following methods are used:

Mechanical.

Fastening is carried out using the so-called telescopic fasteners. They consist of a flange with a smooth outer surface and a tubular rod. Commercially available different sizes of disc dowels allow you to fix roofing cakes of various thicknesses.
Anchors are driven into concrete ceilings, and fastened to the screed with screws with plastic sleeves.
To calculate the required number of fasteners for an insulated flat roof, the default condition is taken as a basis: two units of fasteners for each slab.
For concrete roofs, the coating and insulation are fixed at the same time. If the base is made according to profiled sheets, separately.
In certain areas (, mating lines with vertical planes, etc.), the installation step of fasteners is reduced.

Kleeva.

All layers of the roofing cake, including thermal insulation, are glued onto hot mastic, most often. The insulation must be glued evenly. In this case, the total area of contact areas of the heat-insulating material with the base should exceed its third.
If the roofing cake is completed with a bituminous or bitumen-polymer material, then the installation of the roofing system cannot be carried out in a rainy period, since excess moisture will accumulate in the insulation without the ability to go outside. But when used as a topcoat, it can be glued throughout the year, since the membrane lets out the excess moisture accumulated in the insulation.

Insulation is placed on a flat roof and covered with a waterproofing carpet. A mixture of gravel and pebbles is poured over the waterproofing layer, or paving slabs are laid on plastic supports. The components of the roofing cake are loose. The pie is fixed exclusively along the perimeter, as well as around the roof penetrations.

Green roofs are also referred to as ballast ones. Although it should be noted that the roof with landscaping is inversion, therefore the order of the layers of the roofing cake is different from the traditional one. The insulation is laid on top of the waterproofing, which simultaneously functions as a vapor barrier. The thermal insulation layer is covered with a geo-drainage polymer membrane, on which a soil-vegetation layer is arranged.

Installation of thermal insulation from the inside

Installation of insulation boards from the inside of a building with a flat roof is not physically very convenient, but practical. After all, installation can be carried out in almost any weather. And there is no need to rush to complete the work in a day, because the insulation does not get wet.

The algorithm for the thermal insulation device is as follows:

Along the line of junction of the ceiling with the wall, a bar of a wooden bar is screwed, the thickness of which on one or both sides is equal to the thickness of the insulation.
The same bar is attached from the opposite side.
A block, both or one of the sides of which is equal to the thickness of the insulation plate, are screwed along the line of joining the ceiling and wall.
We install a similar bar from a bar against the opposite wall.
Rigid polystyrene foam boards are perfect for internal insulation.
The ceiling is conventionally divided into stripes.
The expanded polystyrene plate is glued to the ceiling and plank with bitumen mastic and pressed tightly. The marked strip is completely filled with polystyrene foam. If necessary, the extreme plates are trimmed.
On the side of the completed strip of expanded polystyrene plates, pressing tightly, screw another strip.
Next, a strip of insulation is again formed and glued.
Alternating between these two operations: screwing the bars and gluing the thermal insulation, they fill the plane of the ceiling.
A plastic wrap is attached to the slats, fixing with a stapler, and the ceiling is trimmed with some convenient cladding material, for example, drywall.

What insulation for a flat roof is better to choose

Expanded polystyrene brandsURSA XPS... The excellent quality of the thermal insulation material produced by the international holding URALITA attracts many developers. It contains fire retardants that increase the fire resistance of the insulation. This material is excellent for inversion thermal insulation. The slabs have cutouts on the sides, which guarantee their perfect joining without creating gaps.

Extruded polystyrene foam of Russian production is produced in the form of plates, on each side of which there is an L-shaped edge. It provides a perfectly even joining and continuity of the heat-insulating layer, which prevents the formation of cold bridges. Penoplex boards do not absorb water, that is, in this case, you can do without additional protection from precipitation.

EPPS Technonikol... A few words about the products of the domestic company - TechnoNIKOL. The following types of material are suitable for roof insulation:

XPS CARBON ECO - insulation for the roofs of low-rise or country houses.
XPS CARBON ECO DRAIN - Drainage grooves on the slabs facilitate flat roof ventilation.
CARBON PROF is a particularly hard and durable polystyrene foam that is able to withstand huge loads. Used in roofing cakes of high-rise buildings, shops or warehouses.
CARBON PROF SLOPE is no less durable than CARBON PROF, but this material has a special feature. It is supplied as a set of five slabs with different top plate inclination. With their help, they form.

TECHNOROOF 45, 50, 60 and 70 is intended for installation of one-layer thermal insulation of a flat roof. The numbers in the markings indicate the compressive density of the slabs. The thermal conductivity of the material is so low that the roofs of parking lots can be insulated with these plates.

TECHNOROOF boards are also used for two-layer thermal insulation: 50, 60, 70 for the upper layer and 25, 30, 35, 40 for the lower one.

(10 votes, average: 0,00 out of 5)

Thermal insulation of a flat roof is a necessity caused by the desire to create a comfortable atmosphere in the room. In winter, the insulation does not release heat from the house, in summer it does not allow hot air to penetrate. In addition, thermal insulation is excellent at suppressing external noise.

Insulation types

There are different types of insulation.

For thermal insulation of a flat roof, use:

Expanded clay... Loose, cheap material, very easy to install. But due to its thermal insulation characteristics, it is rarely used as an independent insulation. More often the roof is insulated with basalt wool or expanded polystyrene, and a slope-forming layer is made from expanded clay, thus increasing the thermal insulation of the room.
Mineral wool... Not the most expensive material. Has excellent thermal insulation characteristics. But mineral wool is susceptible to moisture. Also, it does not have a rigid base, which is unacceptable for a flat roof, therefore, a concrete screed is arranged on top of it.
Mineral basalt wool... The main difference from ordinary mineral wool is the stiffness of the plates. Able to withstand heavy loads. It is impregnated with a special water-repellent compound to increase resistance to moisture.
Foam glass... The benefits include durability, strength, UV and high temperature resistance. The main disadvantage is the high price.
Extruded polystyrene foam... It has excellent thermal insulation characteristics, is resistant to chemicals, has great strength, and is waterproof. The only negative is the high price.
Styrofoam... Not the foam itself in its pure form, but its pieces, mixed with a cement-sand mixture and poured in as a screed. The main advantage is very cheap.

How to choose insulation

The choice of insulation for a flat roof depends on the characteristics of the roof. So, it can be traditional or inversion.

A traditional roofing cake involves thermal insulation before waterproofing. Thus, the insulation will be protected from moisture, which expands the choice of material.

An inverted roofing pie is the other way around. The thermal insulation is placed above the waterproofing. Most often, this type of roof is used for an exploited roof. When choosing a heater, it is necessary to take into account that it must be as resistant to moisture as possible and at the same time have a high compressive strength.

In addition, it is possible that the sloping layer is created just from the insulation. This will require a special wedge-shaped insulation. It is, of course, expensive, but it is convenient to work with it.

Thermal insulation can be installed in one or two layers. It depends on the floor slabs, which are often made of reinforced concrete slabs and profiled sheets.

In the first case, it is permissible to lay the insulation in one layer, while it must have a compressive strength of at least 40 kPa, after which a screed is poured over it. In the second case, a two-layer thermal insulation is required. The first layer must have a strength of at least 30 kPa, the second - at least 60 kPa. If desired, it is also possible to arrange the thermal insulation of the roof on a reinforced concrete base in the same way. This will improve its quality.

Installation of mineral wool

If we are talking about a traditional roofing cake (namely, it is used most often), then the preliminary stage of work will be as follows:

If corrugated board is used, its lower wave must be filled with insulation. If the thickness of the insulation is twice the width of the wave, this step can be skipped.
Vapor barrier device. The film must be brought to the parapet to the height of the future heat-insulating layer. The longitudinal overlap is 10 centimeters, the transverse overlap is 15 centimeters. The joints must be glued with tape.
Inspection of thermal insulation boards. The rigidity should be uniform over the entire sheet area. There should be no moisture.

Thermal insulation of a flat roof with mineral wool is performed as follows:

Installation starts from the corner. It doesn't matter which one.
Fastening of mineral wool can be made using mastic, or special dowels, at a minimum rate of 2 dowels per slab. In the corrugated board, the fasteners are screwed exclusively into the upper wave so as not to squeeze the insulation. It is permissible to glue the mineral wool to the concrete base with mastic.
Next, the top layer of thermal insulation is laid. In this case, the joints should in no case fall on each other - this will lead to the formation of cold bridges. It is better if the upper plate overlaps the lower one by 1/4.
The upper layer is fixed in the same way as the lower one, using special dowels. To ensure that the fasteners hit the upper wave of the profiled sheet, be guided by the parapet. There you can apply markings in advance. The minimum calculation of the fastening is 2 dowels per sheet. But it is better to make additional fixation in order to ensure a snug fit of the layers one to one. It is important not to pinch the self-tapping screw inside the dowel - this will violate the integrity of the insulation, which will lead to the formation of cold bridges.
Seams, more than half a centimeter wide, are filled with insulation.
The next step is the waterproofing device.

For insulation of a residential building, mineral wool is laid, at least 20 centimeters thick. For outbuildings - at least 12 centimeters thick.

Installation of extruded polystyrene foam

Thermal insulation of a flat roof using extruded polystyrene foam is performed as follows:

Cleaning the base from dirt and dust.
Installation starts from the corner.
It is not necessary to lay a vapor barrier under the expanded polystyrene, it is completely moisture resistant, and condensation is not afraid of it. Therefore, this insulation is often glued to the base using cold mastic or special glue. As a last resort, use polyurethane foam. It is not necessary to apply glue or mastic all over the base of the slab, it is enough to smear a few points. It will not be superfluous to grease with glue from the end, for a snug fit of the insulation to the parapet on the one hand, and for a secure connection of the seams on the other.
Possible cavities are sealed with polyurethane foam. Do not overdo it so that the foam does not squeeze out the insulation.
The seams must be glued with tape in order to prevent the penetration of cement milk into them, due to which cold bridges are formed.
If subsequently the waterproofing will be glued with a gas burner, a concrete tie is arranged on the expanded polystyrene, the minimum thickness of which is 3 centimeters.
Then they wait several days for the screed to dry completely and arrange waterproofing.

The thickness of the expanded polystyrene layer is the same as the thickness of the mineral wool.

Installation of foam glass

Thermal insulation of a flat roof with foam glass is carried out using the following technology:

Cleaning the base from dirt and dust.
Installation starts from the corner.
Foam glass also does not require a vapor barrier. The insulation is fixed with cold mastic or hot bitumen. There is no difference in the process.

Foam glass can be used both on reinforced concrete slabs and on corrugated board. In the first case, the mastic or bitumen is rolled over the base of the roof with a notched trowel to ensure a secure fixation of the thermal insulation layer. Insulation sheets are coated along the edges, for a snug fit to each other and to the wall.

In the second case, foam glass plates are soaked in an adhesive from all sides, except for the top. This is necessary to avoid overspending of bitumen or mastic. At the same time, hands should be protected with rubber gloves, but even so it is not worth lowering them in bitumen, and therefore it is better to hold the sheet in any convenient way, even wooden sticks are suitable for this.

The upper layer is mounted according to the same principle as the lower one on reinforced concrete slabs. First, glue is rolled out on the base, and then the insulation is laid, not forgetting to coat the edges. Mastic or bitumen should protrude outward when the sheets are pressed tightly one to one.
If there is a loose fit of the foam glass plates, and the formation of wide seams (more than 5 millimeters), they must be repaired. To do this, the edge of one of the sheets is cut off at an angle of 45 degrees and shifted towards the unsealed seam, having previously soaked it in bitumen.

Warming with expanded clay

Expanded clay is rarely used as an independent thermal insulation for a flat roof. Rather, it is just an addition to the main insulation.

In addition, with the help of expanded clay, a slope-forming layer is often created. Therefore, the order of work is as follows:

Installation of the main thermal insulation made of mineral wool or expanded polystyrene.
Marking the angle of inclination of the roof, pulling the laces.
Delivery of expanded clay to the roof and stretching it along a string, for this they use the rule.
Excess material is pulled along the edges to ensure a good drainage of moisture from the parapet.
A concrete screed is placed on top of the expanded clay.

The thickness of the expanded clay heat-insulating layer depends on the angle of inclination of the roof. Expanded clay should not affect the thickness of the main insulation layer.

Foam insulation

Before insulating a flat roof with foam, you will have to work hard and break the insulation into small pieces. Styrofoam of any density, any type and any shape will do. The average size of the pieces is 3 * 3 centimeters. To insulate the roof, the foam is mixed with an ordinary concrete mixture and poured on the roof as a screed. The screed must be reinforced so that the concrete does not disperse later.

The main problem is that for a flat roof, you will need a lot of pieces of foam... Also, this type of insulation will not be very effective. Rather, it can be used as additional thermal insulation.

Requirements for thermal insulation of coatings of buildings with a flat roof (such structures were in most new buildings), erected during the Soviet Union, were at the level of 1.5 m² ° C / W, but this was clearly not enough: the roof often froze through. Modern standards increase this value by more than 3 times. The need to save energy resources that are increasing in price every year makes flat roof insulation a widespread event. However, good results can be achieved only with the help of high-quality heat-insulating materials and subject to the work technology. This will be discussed further.

Video instructions for laying insulation for a flat roof

Requirements for thermal insulation materials

Heat loss through the roof can be prevented by using materials with low thermal conductivity. The roof is a fencing element of the structure and during operation it experiences serious loads associated with changes in the ambient temperature. Its inner surface (in fact, the ceiling) has practically the same temperature as the air in the room. The outer surface cools down in winter to negative temperatures and heats up in summer, sometimes up to hundreds of degrees with a plus. But such conditions should not affect the ability of the roof to protect the premises of the building from both cold and heat.

When choosing insulation for a flat roof, it should be borne in mind that their service life depends on many factors, including temperature and humidity conditions, the presence or absence of diffuse and capillary moisture, mechanical influences. The heat insulator must have a long service life and at the same time retain all its qualities: it must be a moisture resistant, environmentally friendly material, resistant to biological and chemical influences and comply with the requirements of sanitary and fire safety norms and rules. In terms of the requirements for mechanical strength: thermal insulation materials must have sufficient compressive and tensile strength, they must not delaminate. Therefore, when purchasing materials for roofing work, it is necessary to familiarize yourself with the accompanying documentation: the quality must be confirmed by appropriate certificates.

Insulation of a flat roof with expanded polystyrene

Roof insulation device: general rules

Most often, roof attics in multi-storey buildings are non-residential premises and do not have thermal insulation. In this case, roof insulation does not make sense - only the attic floor should be insulated. If you need to arrange a living room under the roof, you cannot do without insulation.

If the house is under construction, everything is simple: thermal insulation is laid on top of the lathing and closed with waterproofing material. The roofs of buildings in service can only be insulated from the inside. Both options have the right to life and are used equally successfully, but external insulation requires certain skills and therefore only professionals can do it. Laying materials from the inside can be done on your own. At the same time, it is necessary to carry out the work in a comprehensive manner: water pipes, weirs and water collectors, which are located in the attic, also need protection.

It is easiest to work with mineral wool, glass wool materials and boards made of foam and extruded polystyrene foam. They have a rectangular shape, fit well and fit tightly in rows. But it should be remembered that the minimum thickness of the material is 25 mm, and for high-quality insulation you need at least 100 mm: this means that mineral and glass wool slabs will have to be laid in several layers.

It is important during the execution of the work not to forget about the need for laying vapor barrier material and waterproofing protection. A significant temperature difference between the inside and outside causes condensation to form under the roof, which does not change the properties of heat-insulating materials, especially cotton ones, in the best way. And for a wooden lathing, moisture is not an ally, but the cause of the appearance of mold, mildew, decay: if damage to the wood was noticed during the work, such parts are subject to special processing or replacement. In addition, steam from living quarters is also harmful. Hydro and vapor barrier eliminates the need to replace the heat-shielding layer.

This is how a puff cake of an insulated flat roof looks like

It is necessary to repair or replace the electrical wiring in the attic, especially the one attached to the roof: a breakdown in insulation or a short circuit can cause a fire. Modern heat-insulating materials, although they meet fire-prevention requirements (do not support combustion), will still not withstand in conditions of an open flame.

Flat roof device: outside insulation (exploited version)

An exploited roof can be insulated with rigid heat-insulating plates from the outside. The beams of the supporting structure are covered with panels, which form the basis for thermal insulation boards, on top of which, in turn, paving slabs are located or a layer of pebbles is poured. At this stage, the help of specialists is needed, who must make sure that the supporting structures can withstand the weight of the materials, and the coating does not leak.

Such a roof, the surface of which can be used, for example, for the construction of a summer terrace, parking lot, winter garden, is called inversion. The cost of such a roof is very high.

The procedure for insulating it is as follows:

on top of the reinforced concrete floor slab, a cement-sand mortar is screed: it is laid under a slight slope (3-5 degrees);
a layer of waterproofing material is being laid;
the turn of the slabs of extruded polystyrene foam (EPS) of high density with closed pores comes: this material, due to its waterproofness, does not prevent a small amount of leaked moisture from draining to the water collectors;
a filtering fiberglass is laid on top of the EPSP: water passes through it freely, but solid particles are retained;
a layer of gravel or pebbles without sand is poured: it will be washed away by rain;
the top layer is made of paving slabs or paving stones.

The top layer of the exploited roof - paving slabs

A good insulation for inversion roofing is foam concrete: it is applied over the vapor barrier material with a layer of 0.27 m in the area of the gutters. Above - foam-fiber concrete in the form of a screed 0.03 m thick. The next layer is a fused roof made of Euro-ruberoid.

Insulation of an unexploited flat roof

Such a roof can be insulated both outside and inside. The main element of its supporting structure is a metal tile, a corrugated sheet or a reinforced concrete slab. You can insulate the old roof in one layer - glass or mineral wool is suitable for this. For a new roof, you need two layers.

Board material (EPS) should be chosen with a higher density: when laid on top, it will have to withstand the weight of a person. Paths for heat loss, the so-called "cold bridges", can form in the pressed-in places. It is necessary to arrange the slabs in a staggered order: there should not be long butt joints. Plates should be fastened using plastic dowels: metal ones are more expensive, and in addition, they can also be "cold bridges". You can use glue as an additional tool. The slots in the joints should be sealed with polyurethane foam; places near the sides and parapets are also processed.

Insulation scheme for an unexploited roof

The process of insulating a flat roof in this case consists of the following stages:

a layer of vapor barrier material is laid on top of the reinforced concrete slab: it is fixed with glue;
a layer of mineral wool is laid or EPSP boards are laid;
expanded clay is poured: it is distributed in such a way that a slight slope is formed;
the next layer is the device of a cement-sand screed (about 40 mm) with the use of reinforcement;
waterproofing material is laid;
a soft roof is fused.

Recently, a sprayed coating of polyurethane foam is often used. It has the necessary rigidity and you can walk on it safely. This material does not require additional fastening, but it is necessary to protect it from UV radiation using a special paint.

Sprayed polyurethane foam is protected with a layer of special paint

Thermal insulation of a flat roof is fraught with many difficulties; this business requires certain knowledge and skills. In order to avoid annoying mistakes, you should use the services of specialists.