Build Daily

August 12, 2017 18:06

Insulation of flat roofs

flat roof - an inexpensive and practical way to structure any arrangement.Often it erected over the high-rise residential buildings, industrial facilities, garages and porches (verandas, terraces).In the case of residential buildings flat roof be sure to insulate, otherwise it will be confused by a little.That's what we'll talk in today's article - insulation of flat roof with his hands.


Features warming

Need for roof insulation, including a flat, obvious - anyone familiar with the concept of convection from the school physics course, should understand that the air is being heated, rushes up.If it does not meet the top of a decent hedge, then left the room without hindrance.In other words, all efforts to warm the house under a flat roof will be reduced to nothing.

However useful side insulation of the roof does not end there.In

addition, the insulation that retains warm air, it prevents abrupt temperature changes inside the roofing pie.Let us all to the same school physics course.When the cold air of the street facing a heated stream, rising out of the house, the reaction produces condensate - tiny water droplets.Accumulating condensate permeates the layers of roofing pie and wood elements, causing rapid wear.For this reason alone laying insulation under the roof sheathing is not enough - you need to protect its vapor barrier membrane, which will release condensation from the heat insulation and contribute to its rapid evaporation.

insulation , flat - krovli1

It turns out that the device flat roof insulation means using not only thermal insulation material, but also a vapor barrier.Priority stacking depends on the type of roof.Flat roofs are classic and inversion.In the first case, based on the support plate on which a vapor barrier is laid, and then the insulation.It, in turn, close the roll waterproofing bitumen.It simultaneously protects the insulation from moisture and a topcoat.Such a roof can be found in the multi-storey buildings in any city.It is also worth mentioning that the classical roof can be exploited and unexploited.As the name implies, operated roof can be used, that is, there have equipment, furniture, to make the superstructure, in general, to use it fully as a secondary surface.Covering unexploited roof is not adapted to high loads, but both views insulation passes through the same scenarios.


inversion roofing technically much more advanced version of traditional.First, the carrier plate is poured a layer of gravel, expanded clay or gravel.The thickness of the powder should be at least 5 cm. Put waterproofing, insulation and then, pour all the concrete and covered with a screed finishing materials on a drain pad.The main difference in the installation of insulation above the waterproofing that allows you to keep the hydrophobic layer from harmful UV rays, temperature extremes and mechanical damage.As a result of inversion flat roof is much longer traditional and is automatically operated - durable concrete screed (especially if it is reinforced) allows to arrange seating areas and open-air sports.

Note that a heater, as well as on all other layers of roofing pie, will be provided by various types of loads: weight of snow, wind force, weight of the overlying material, etc.Because a heat insulation material for flat roofs make high physical and mechanical requirements.In addition, experts strongly recommend to choose the most hydrophobic material, since it is impossible to guarantee 100% protection from moisture.For details on selecting a heater, we'll talk later.

Methods insulation of flat roofs

Insulation of flat roofs is carried out by one of two schemes: in one or two coats.Single-layer insulation is important for industrial buildings, garages and warehouses.Suitable for the exploited and unexploited roofs (in the first case, one must have a reinforced concrete tie topcoat).Placing insulation on the same plane gives moderate protection from condensation and excessive heat loss, but to create a comfortable life for the warm climate allows a two-layer insulation.


double layer insulation scheme, as you might guess, involves laying two layers of insulation material in different planes.Lower base layer to be different thermal resistance and strength at low thickness from 70 to 170 mm.The top layer is responsible for the distribution of a mechanical load on the entire surface of the system.Its thickness is substantially smaller than the lower layer, and from 30 to 50 mm, but it has a high compressive strength and rupture.This functional distribution of two layers of insulation significantly reduces the weight of the roof of the pie as a whole, thereby reducing the load on the roof provided the overlap and the foundation.


Choosing insulation for roofs

for flat roof insulation from the outside using a variety of materials, but after examining the above information, we can already identify some basic selection criteria.Firstly, the maximum hydrophobicity.Secondly, the strength and density.Third, the opportunity for low weight.Consider the materials used in modern construction.

most often in urban construction and private use Sediment materials because of their availability and cheapness.It is about Leca (foamed high-pressure mud) and Pearl (light coarse sand with good insulating properties).Unfortunately, low cost and availability advantages of these materials are limited and - other parameters are not capable of competing with fibrous or polymeric insulators.They are relatively heavy, and with their help create a perfectly flat surface at a slight slope is difficult.


second most popular are mineral wool and polystyrene.Mineral wool holds heat well, is easy to operate, does not burn, but it needs a high-quality waterproofing - if it gets wet a little bit, it will cease to be protected from heat loss.Extruded polystyrene is not afraid of water, has a high strength, ease of installation and relatively low cost.However, it is best to use to create an inversion of the roof, because the material is very sensitive to UV and different flammability.

sandwich panels , polyurethane foam

.Not so long ago appeared on the market in mineral wool slabs made of basalt rock.It is much stronger in compression and tear than older counterparts, are not so much afraid of water, and allows you to create a sufficiently strong cover everything without heavy concrete screed.


Finally, the newest, high-quality and expensive insulation is polyurethane foam.The special composition is applied to the prepared surface by mechanical spraying, after which he foams, hardens and creates a solid waterproof crust, perfectly retains heat and is not susceptible to UV light.In the West, the polyurethane foam has long been used for thermal insulation of roofs, including flat.In our latitudes, its benefits have only begun to appreciate.

polyurethane -3

Pros of polyurethane foam for thermal insulation of roofs:

  • very low thermal conductivity (polyurethane 0.022 W / m², mineral wool 0,055 W / m²);
  • requires minimal surface preparation (clearing of debris, you can not align or process);
  • enough for high-quality thermal insulation layer thickness of 5-6 cm;
  • absolutely seamless coating that prevents the formation of potentially risky sites leaks and drafts;
  • absolute hydrophobicity and vapor permeability (allows you to save on hydro and vapor barrier);
  • spraying can be used to provide additional waterproofing;
  • high rigidity solidified coating on top of it allows you to equip the concrete floor;
  • relatively low density (does not give a strong load on the bearing elements);
  • environmental safety;
  • possibility of covering surfaces and objects of any shape (to protect against leaks and heat loss problem areas exit pipes);
  • not burn or support combustion;
  • life of more than 25 years;
  • high speed operations.

Thus, polyurethane foam and replaces insulation and vapor, and waterproof.The only drawback - do such work with their own hands will not work, because it requires special equipment and handling of a two-component material skills.

technology insulation

It is time to tell you how warm the flat roof of their own.Since the disadvantages of bulk insulators do not allow to speak about them as about the best options for everything, we touch on the use of mineral wool and extruded polystyrene.

mineral wool

immediately builds mention that not all kinds of mineral wool can be used for thermal insulation of flat roofs or exploited classical soft roof.It is best suited for this purpose, Basalt plates, fibers which are directed in different directions - it allows them to withstand high loads.Of course, you can protect the fragile insulation screed (dry or wet), but it will create an additional burden on the supporting structures.

insulation , flat - krovli3

Technology mineral wool insulation:

  1. basis for laying slabs are reinforced concrete or trapezoidal sheet metal.
  2. Regardless of the type of substrate before laying the insulation of his dim vapor barrier membrane.If we neglect this moment in time mineral wool soaked with condensate and no longer retain heat and waterproofing laid on top of them adorned "blisters".Vapor Sealing membranes are one- and two-sided.In the first case between the membrane and the base should be left free space in just 3-4 cm, so that the condensate can freely evaporate.When using two-way membrane vent pockets to keep optional.Alternatively, the membranes can use conventional construction polyethylene or facing materials (bitumen, polymer bitumen).As a result, a vapor barrier should close all the horizontal and vertical planes, and start the coating must be slightly above the level to which it will reach the insulation.
  3. mineral wool slabs should be laid in one or two coats.In the second case it is necessary to calculate in advance the future roof of cake thickness and enhance the insulation layer and high strength thin plates if necessary.Usually this comes in the northern regions, where the humidity and temperature variations are so great that incapacitate conventional heaters.
  4. to the base plate attached telescopic dowels or glue on bitumen - a method depends on the type of substrate.Plugs are best suited for profiled sheet, but also for concrete slabs, they fit, but for concrete fasteners are more expensive than metal.If you prefer a mechanical attachment method, a vapor barrier should be surfaced.Gluing insulation on bitumen rather troublesome and expensive, but this method is recommended for the insulation of roofs with concrete bases.On the surface, a layer of bitumen and paste butt plate.If you want to create a second layer of insulation, bitumen coat with the surface of the first layer and paste it extra plate "in the Extension" (to the joints of the second layer does not coincide with the first joints).
  5. If the heater was fixed mechanically, and the waterproofing on top of it should be recorded as well, ie with dowels.

Video of the flat roof insulation with mineral wool:

extruded polystyrene

Extruded polystyrene foam is highly durable and water-resistant, and therefore most often used for thermal insulation of roofs inversion.On the plates are slotted locks, which provide a very dense surface, but for greater reliability is recommended to glue all joints with duct tape construction.

penoplex - laying

beauty of Styrofoam that working with him is very easy and fast:

  1. first base plate on the plate stack, slit prokleivaya connections construction tape.If you want to put the second layer, the plate is mounted "in the Extension."
  2. top of foam polystyrene insulation littered geotextile designed to protect the lower layers of the cake from the contamination and mechanical damage.
  3. On geotextile poured 5-10 cm layer of gravel or crushed stone.Sometimes additional drainage geotextile between the powder and placed a profiled membrane.
  4. Finally, gravel or gravel and pour the screed placed seal coat.If operated roof is planned to plant lawn grass or flowers, on top of the filling should be paved with an additional layer of geotextile, and then pour 15-20 cm of fertile soil.

insulation , polystyrene foam

insulate the flat roof is not so simple, but this measure belongs to the category required if you want to live in a warm house and not pay for heating.