Roof Insulation

Therefore, for energy-efficient and durable operation of any building, roof insulation must be carried out flawlessly and professionally.

One of the most important factors affecting these indicators is the temperature and humidity regime, which a specific insulation material can maintain. For roof insulation, materials and methods are used that most effectively preserve heat in the building according to current construction standards and regulations. The insulation material must have a certain vapor permeability (allowing vapor to pass through, letting the roof breathe) and low water permeability (not allowing water to pass through).

Types of Insulation Materials for Roof Insulation

For roof insulation, a specific group of materials—roof insulation materials—are used, differing in thermal conductivity, vapor permeability, moisture-repellent and mechanical properties, as well as fire resistance, durability, ease of installation, and, of course, cost.

The main characteristic of insulation materials is their average density, measured in kg/m³. All insulation materials are divided into very light, light, medium, and dense. A high-density insulator does not necessarily provide higher insulation performance, but it will withstand higher mechanical loads, while also increasing the load on the supporting structures of the building. Insulation density can range from 20 to 200 kg/m³.

Primary Types of Insulation Materials

• Mineral and basalt wool. Produced from rock fibers in the form of ready-made boards or rolls of various sizes. Can be laid in one or several layers to achieve the desired result. Has minimal hygroscopicity, good sound insulation, and does not burn. During production, mineral wool insulation must undergo mandatory toxicological and radiological testing.
• Glass wool and fiberglass. This material features high sound absorption, low weight, and relatively low cost, while matching other insulators in thermal performance.
• Polystyrene foam (foam polystyrene) and extruded polystyrene foam (PENOPLEX). Both materials are easy to process, lightweight, have very low thermal conductivity, and almost do not absorb moisture. They differ in thermal properties—for example, PENOPLEX is almost impermeable to air, while foam polystyrene has good air permeability. Both materials are flammable, but the application of a fire protection layer or anti-pyrene impregnation resolves this issue.
• Polyethylene foam (Penofoam). A composite insulation made from foamed polyethylene, coated with aluminum foil on one or both sides. Characterized by low thermal conductivity and moisture absorption, as well as low thickness.

Insulating Sloped Roofs and Attics

Roof insulation is typically performed using two main methods: single-layer or double-layer insulation. The installation process requires that the entire insulation layer be of uniform density.

Sloped roofs on rafters can be insulated with low-density materials (25–50 kg/m³), designed only for atmospheric and temperature exposure.

For attic spaces, lightweight insulation materials such as glass wool and mineral wool boards (up to 30 kg/m³) are most commonly used, as they do not impose significant additional load on the structure. To prevent air leakage and heat loss, the insulation surface is covered with a hydro- and windproof sealant layer on top, and a vapor barrier layer is installed below.

Insulating Flat Roofs

In new construction, a two-layer method is traditionally used for flat roofs, where the lower layer provides primary thermal protection, and the upper layer distributes the load across the entire insulation structure. A single-layer method is used during repair or renovation of old roofs.

For flat roofs, dense insulation materials capable of withstanding significant loads from water and snow, which often accumulate on such roofs, must be used. Flat roofs made of corrugated steel sheets can be insulated with mineral, basalt, or polystyrene boards with a density of up to 220 kg/m³. Flat roofs on reinforced concrete slabs, due to their high weight and potential operational and snow loads, must be insulated with even denser materials, such as PPSJ-200 boards.

Insulating Roof Panels (Sandwich Panels)

Roofs built from framed panels are insulated with the lightest materials (e.g., basalt or mineral wool) with a density of up to 70 kg/m³.

Non-framed panels are subject to wind and temporary mechanical loads, so they must be insulated with materials of higher density, between 50 and 100 kg/m³.

Spray Foam Insulation

This is one of the most modern methods of insulation. Spray foam is applied to surfaces of any shape. Polyurethane foam is sprayed from inside across all structural elements, expanding and filling all gaps, joints, and cavities. There are no seams, and no additional fastening is required. The material is resistant to rot and microbial damage and has a long service life—no less than 30 years.

Properly installed insulation will significantly reduce heating costs for your home.