With what type of insulation should you isolate your roof knowing that a poorly insulated roof can be the source of 30% of heat loss in a home? How to isolate it? With what material? A short overview.
What insulation for what type of roof?
Here is what we recommend, depending on the type of roof in your house.
Extruded polystyrene panels (XPS).
- If the attic is not used, insulate the floor with cellulose, glass wool or blown rock or PUR boards or foam;
- if the attic is heated, insulate the roof with rolls of glass wool or rock between the houses; if the cottages are not thick enough, complete with signs.
Types of roof insulation
- The glass wool
Obtained by melting, centrifugation and blowing glass of recovery until a tangled wool mattress is formed which traps the air, the glass wool is a natural insulator. It is in the form of rolls or flakes to blow.
Its advantages: it reduces the transmission of airborne noise and shock, it is non-flammable, rot-proof, easy to handle and easy to install.
Its disadvantages: it is very irritating, even if progress in this area have been made. Better to wear a mask and gloves when laying it. It requires the installation of a vapor barrier to regulate the indoor humidity.
Rockwool is made of basalt rock. Its manufacturing process consists of melting and fiber zing the rock, until a tangled wool mattress that traps the air. It comes in the form of rolls or panels and is used in the same way as glass wool.
Its advantages: it offers good thermal insulation and better sound insulation than glass wool; it is permeable to water vapor and non-flammable.
Its disadvantages: the same as glass wool.
- The blown mineral wool
The blowing technique is a method used for the insulation of attics lost of new houses or to renovate. Using a blowing machine (a carding machine) the mineral wool is projected into the roofs over the entire surface homogeneously, quickly and efficiently.
Its advantages: the homogeneous projection helps to eliminate the thermal bridges and guarantees a very good quality of the insulation. The flakes of insulation clog up all the spaces that rollers would have difficulty covering.
Its disadvantages: the price is high and it takes a special machine to proceed with the insulation by blowing. It cannot be used for open living spaces as flakes are scattered everywhere.
- Cellulose wadding
Increasingly popular in eco-construction, cellulose wadding is an insulating material from newsprint recycling. It comes in bulk, panels or rolls and adapts very well to hollow spaces and inter-lodgings.
Its advantages: it is an ecological material of a great longevity, with a very good thermal inertia and offering a very good acoustic insulation.
Its disadvantages: slightly more flammable than other insulators. But it still delays fires because the cellulose is covered with carbon in contact with the flames, which has the effect of slowing the spread of fire and heat.
- Polyurethane (PUR)
Polyurethane is a honeycomb structure containing a more insulating gas than air. In panels, it is used in screed insulation and outdoor. It can also be used as foam for caulking joints.
Its advantages: good thermal and acoustic insulation, high mechanical resistance, good resistance to humidity.
Its disadvantages: synthetic material, it can be toxic in case of fire.
- Expanded polystyrene
Expanded polystyrene is made from crude oil. Its manufacturing process consists in binding together a multitude of balls by compression during a molding that will trap the still dry air.
Its advantages: good insulation capacity, impermeability, very light material, high mechanical resistance, easy to work and good price.
Its disadvantages: synthetic material, poor acoustic performance, flammable, fragile, toxic release over time and in case of fire.
- Extruded polystyrene (XPS)
Extruded polystyrene is also made from crude oil. Better than expanded polystyrene, it is in the form of panels.
Its advantages: better insulation performance than expanded polystyrene, impermeability, very light material with high mechanical strength and easy to work.
Its disadvantages: more expensive than expanded polystyrene.