The roof is the first so of the attics are eligible on the energy loss in a dwelling. The rate of energy lost through this area is estimated at over 30%. The best solution to limit these heat losses and reduce energy consumption is toinsulate the atticwhether they are lost or not. The choice of a thermal insulating material is vast: insulation performance and properties are varied and there are many natural insulation for many years in the market. What are the most frequently used methods for this type of insulation and what are the loans to which you can take out for carrying out roof insulation work? 2020 guide to materials and methods of insulation for lost or habitable attics.
What are the different types of insulation used for the insulation of lost and converted attics?
There are many types of insulation for the insulation of the attic. Some are natural and some are chemical. As a chemical insulating material, we distinguish:
- Glass wool: approx 75% of the attic of French households are insulated with this mineral insulator.
- Rock wool: this insulation is also very popular. It exists in the form of flakes, panels, rolls, etc. What him allows easy adaptation to different configurations that the roofs present.
- Expanded polystyrene: it comes in the form of plates. This material is quite economical, strong and eco-friendly.
- Sandwich panel: this is a robust, waterproof and resistant multi-layer monoblock, the insulating part of which is often made of polyurethane or expanded polystyrene.
Financing of attic insulation work via a work loan
To insulate your lost or habitable attic space, whether from the inside (ITI) or from the outside (ITE), several financial aids are available. Among these is the insulation work loan. This is a consumer credit reserved for people who wish to borrow the sum necessary to carry out insulation work in the attic of their accommodation. Still called work credit, this type of loan cannot exceed 75 euros.
There are different types of work loans and they are divided into two main categories what are :
- Bank works loans: these loans are allocated only to creditworthy borrowers. They may or may not be attached to the performance of the work they finance;
- State subsidized loans: as a general rule, they are means-tested. Among them are the PAS (Social Accession Loan), the Pass-travaux, ANAH loans, the home improvement loan and the Eco-PTZ (Zero Rate Loan).
The insulation of lost attics and convertible attics limits heat loss through the roof. It is therefore effective in achieving significant energy savings. Various techniques are used for this type of insulation and you have the choice between chemical and natural insulation. In addition, roof insulation work is eligible for a loan works, subject to acceptance of your file by an organization such as Domofinance.
What are the different techniques used for the insulation of roofs lost or not?
The lost attic designate a space below the roof and which is uninhabitable for several reasons. Most often, it is the poor layout of the frame, the insufficient headroom (less than 1,80 m), or the inclination of the roof which is less than 30%, which makes it impossible to fit out. Convertible or habitable attic space have enough space, and it can be converted into a living space. You can decide to make it an attic or even a bedroom.
Different types of techniques are used to insulate lost attics and habitable attics. For the first (lost), there are three processes: blowing, spreading and laying rolls of wool on the ground. For the second (habitable), we practice insulation from the inside and the outside (sarking).
The technique of blowing or flocking, for example cellulose wadding in lost attics
This method is the one that is most used when it comes to isolating lost attics, especially those that are difficult to access. It consists of projecting the chosen insulation on the ground or under the roof. This process requires the use of a machine called a carder or blower. This reduces the insulating material to flakes and spreads it in the attic. A simple hatch is enough to carry out the work. This technique has the advantage of being very efficient since it completely covers the area on which the work is performed. It is also appreciated for the speed of its realization.
The spreading method
This attic insulation technique is similar to that of blowing. With the only difference that she does not use any machine. The insulation is purchased directly in the form of a flake and the installation is done manually using a rake. Spreading is suitable for insulating lost attics which are easily accessible.
Laying insulation in rolls on the floor
Here, it is a question of laying and fixing rolls of wool on the walls to be insulated. Although more expensive than the other two techniques, it achieves good thermal performance just with a single layer of insulation between the joists. But to have more guarantees, it is recommended to apply a second to cover them. In addition, she enjoys high durability.
Insulation from the inside
This form of insulation is very effective. She is made with rigid and semi-rigid panels. The installation is done by fixing a layer of insulation between the rafters or a double layer under the crawlers at the roof level. This process has the advantage of being less expensive since it is not complicated to perform and does not involve any work on the roof (provided of course that it is in good condition). In addition, if the configuration of the frame is good enough to allow it, it can be left exposed. Which adds charm to the aesthetics of your interior.
Insulation of the attic from the outside or Sarking
Sarking requires some work to be done beforehand. This concerns in particular “decurling” or “tearing off”. This makes it much more expensive than insulating the attic from the inside. It is therefore advisable to prefer this method only if you make a renovation of your roof or if your accommodation is under construction. However, insulation from the outside does not encroach on your space and thus preserves the available surface. In addition, she is effective in limiting the impact of climatic variations.
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