How to insulate walls and save on heating and cooling costs? Systems for insulate the walls there are basically three: from the inside, from the outside or in the cavity. The results are different, but the choice of the type of intervention does not depend only on the technical quality to be achieved. The situation of the building and the available budget also affect.
Why insulate the walls
The first thing to focus on is why the walls are insulated and, if the thermal insulation is insufficient, why it needs to be added. The reasons are two:
- avoid or solve the heat losses that cause the energy bill to rise;
- avoid or solve mold problems on walls caused by thermal bridges.
Whatever the reason, insulate the walls increases the level of living comfort inside the home; and consequently the real estate value also increases.
A fact: the energy consumed in residential buildings for heating and domestic hot water corresponds to about 30% of national energy consumption. And about 25% of the polluting emissions of carbon dioxide into the atmosphere. Insulate the walls home helps the national economy and protect the environment.
How to insulate walls
Thermal insulation from the outside. It is also called 'insulation coat' and is the solution that allows for the best results. In fact, it is a matter of gluing a uniform layer of insulating material to the external walls of the entire building, thus solving (although not completely) the problem of thermal bridges that cause heat dispersion to the outside and the proliferation of mold inside of. The external insulating coat is a demanding and expensive intervention, which becomes particularly convenient when a renovation of the facade is planned. Difficult to do it yourself, it is almost mandatory to rely on a specialized company.
Thermal insulation from the inside. It is also a 'coat', but applied on the inner face of the perimeter walls of a single housing unit or a single room. It inevitably causes a decrease in living space and only partially solves the problems. On the other hand, an internal thermal coat is not very expensive (also because scaffolding is not needed) and you can try it yourself. Keeping in mind that radiators and electrical outlets may need to be re-arranged.
Thermal insulation in the cavity. If the walls have a cavity, it can be filled with granular insulating material. The technique is that of blowing with special devices. The result is not always flawless because it is difficult to evenly fill all the spaces (especially at the top). On the other hand, the expense is usually modest, which makes the intervention affordable overall.
With what to insulate the walls
The choice of insulating material affects the cost of the intervention and performance. From the point of view of origin, there are thermal insulators of organic origin and synthetic insulators. Breathable and non-breathable insulators. Insulators with a polluting or less polluting production cycle. Easily disposable insulators and others less so.
From the point of view of 'shape', thermal insulators for insulate the walls they can look like:
- felts (rock wool, glass wool, sheep wool, hemp, cotton ...)
- panels (wood fiber, cork, glass wool, rock wool, polystyrene, polyurethane, polyester fiber, expanded polyethylene ...);
- loose (cellulose fiber, cork, expanded clay, perlite, vermiculite, polystyrene beads ...)
- foamed (polyurethane foam)
And if windows are the problem: How to insulate windows and save money
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