Roof insulation

The insulation process plays a particularly important role in the construction of roofing and attic rooms. You can spend tremendous efforts and funds to ensure proper heating of a house, but without the roof insulation, these measures will not give a desired effect.

Roof insulation is necessary in order to prevent valuable heat from leaving the house - a layer of insulating material will keep the warm air inside the building. If the attic is lived in, then the slopes of the mansard roof are insulated; if it is not used for such purposes, then insulation is used for attic flooring.

Roof insulation options

The modern market offers a wide variety of roof insulation. To choose the most suitable option from a wide range, you should familiarize yourself with the most frequently used materials:

• basalt insulation is valued for ease of installation and relatively low specific weight. In addition, the material is known for its excellent soundproofing properties;
• mineral wool roof insulation in many cases is suitable for complicated humidity conditions. It is characterized by increased hydrophobic properties, low thermal conductivity, vapour permeability and excellent fire resistance;
• polyfoam is a budget option. It is easy to process, durable, frost-resistant and biologically pure;
• extruded polystyrene is 98% air and 2% polystyrene foam. It is a lightweight, environmentally friendly and relatively cheap material. It is often used to insulate flat roofs, less often - pitched roofs;
• cellulose roof insulation is a new product on the construction market. It is environmentally friendly, airtight, and exhibits low thermal conductivity. Its fire resistance is ensured by adding special additives.

Thermal insulation from such companies as Knauf, Isover, RockWool, Ursa, Termolife and others is in great demand on the Russian market.

What influences the price of roof insulation

The price of roof insulation plays an important role in choosing a material. You should not completely rely on the recommendations provided by store consultants or marketing tricks of the manufacturer. The main operational characteristics of the insulator influence its price:

1. Freeze thaw resistance is one of the most important properties of roof insulation in our climate. This parameter will directly affect how the roof will withstand repeated freezing and thawing that occur cyclically.
2. Fire safety - when all other properties are the same, it is necessary to make a choice in favour of non-flammable, fire-resistant materials.
3. Water resistance - insulation should not change its properties under the influence of water and should not be hygroscopic, as damp insulation exhibits high thermal conductivity and provides poorer thermal insulation.
4. The low specific weight of the material is important, so that the insulation layer does not make the roof heavier - this can be dangerous.
5. Environmental safety - you should use clean, non-toxic materials. Insulation should not contain harmful substances and smell bad.
6. Durability - insulation must retain its properties for a long time, so that the roof does not need major repairs as long as possible.

Roof insulation thickness

The required material thickness will directly depend on the climate zone. The lower the average temperature in the region, the greater should be the thickness of the insulation. It is necessary to take into account the materials that are used for the structural frame. Anyway, the necessary thickness of insulation must be calculated for each specific case.

For attic flooring, the heat transfer resistance value ranges from 1.8 to 2.5 m² • ° С / W. The approximate thickness of the insulation should be from 10 to 16 cm. For the roof, the resistance coefficient is approximately 2.2- 4.95 m² • ° С / W; in this case, the material used has a thickness between 15 and 30cm.

Useful advice

The following recommendations will help you to avoid mistakes when insulating a roof:

• Prior to roof insulation work, inspect the truss structure and flooring slabs. If you find any defects, immediately do the repairs;
• Pay special attention to the rafters - they must be strong enough. The damp and rotten parts of the structure should be replaced;
• Treat the trusses and elements of wiring and plumbing located in the attic with antiseptic;
• The width of the selected material is no less important than its thickness. Installation of too narrow rolls of insulation is fraught with cracks. Before making a purchase, calculate the optimal width, because it is not only the price of roof  insulation that is important, but also the quality of the material and work;
• make sure that the material being used is completely dry. Otherwise, the truss construction will eventually rot;
• Install insulation without gaps;
• pay attention to the junction of the ceiling to the load-bearing walls. Here the insulation should be affixed to the structure as closely as possible.

Vapour barrier and waterproofing

Regardless of the price of roof, it needs a high-quality vapour barrier and waterproofing. Its main task is to protect the material from moisture and steam. The roof insulation process consists of the following steps:

• Installation of waterpoofing

  The insulating layer must be fixed, so that the insulation does not move and “cold cracks” do not appear

• Installation of insulation between the rafters

  Insulation layers should fit snugly to the frame structure and be attached between the rafters. The material is laid from the bottom up. Between it and the waterproofing, a gap of at least 2 cm is left for ventilation in order to prevent the formation of condensate and rotting wooden slings. It is necessary to ensure that the insulationlayers do not sag and there are no gaps between them.

• Installation of a vapour barrier

  This layer prevents the penetration of moisture inside the insulation and removes it from the insulation outside. The vapor barrier is attached to the rafters with a construction stapler, the seams are fixed with a sealing tape.

• Securing insulation

  The layer is fixed with a counter-grid - wooden planks across the rafters.

Roof insulation is not the most difficult task, and you can manage it on your own. If you need advice or the help of experts, get in touch with the specialist of the North House company.