Insulation by blowing

Insulation by blowing

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Architecture technology

Published on

29 June 2023

Insulate by blowing

What is the best material for blowing walls?

The insulation of your home represents a solution that allows you to obtain various advantages. The internal environment becomes in fact more livable thanks to an improvement in the temperature both in summer and in winter; in addition, considerable energy savings and strong acoustic insulation are obtained.

But how insulate in the best way your home? One of the best solutions is represented by blowing the walls. Below we will explain what it is, which materials to use and which one represents the best choice.

What is the blowing of the walls and the usable materials

The blowing of the walls represents one of the interventions of energy efficiency which allows you to perfectly insulate homes. Especially those built in the 70s and 80s the walls were characterized by cavities as there is an empty space between the two faces that make up the wall, the internal one and the external one.

Technically blowing the walls means inject inside of the same an insulating material through a series of holes made along the walls at a regular distance of about 1 meter and at most 30 centimeters from the floor. 

The intervention of thermal insufflation can be done both from the inside of the walls and from the outside, although it is preferable to use the latter solution. In fact, working from the outside represents a less invasive technique as it does not require the intervention of technicians from inside the accommodation with all the resulting consequences.

But what are the insulating materials that can be used for blowing the walls?

Generally the most used are the following:

  • fiberglass
  • cellulose fiber
  • perlite
  • granular cork
  • granular vermiculite
  • expanded polystyrene in pearls
  • Rock wool

Let's analyze in detail the various materials with the pros and cons

One of the insulating materials that best lends itself to insulation by blowing the walls is represented by glass wool which in an innovative version, eco-sustainable and water-resistant, is applied with the technique blowing into the cavities of the walls.

It currently represents the best solution on the market to guarantee the thermal insulation of real estate units, above all thanks to the speed of application: in fact, in just one day it is possible to insulate an interior apartment.

The only disadvantage it presents is the cost on average higher than the other usable materials but thanks to the incentives for thermal insulation possible to deduct part of the expenditure incurred.

If you want more information on this material, here you can find an in-depth analysis on blowing with glass wool.

Cellulose fiber 
This product falls into the category of natural insulators, that is, they do not contain synthetic elements or elements of petrochemical origin. It has the advantage of providing a high insulating and acoustic power and is completely recyclable. The disadvantage is that – even if treated – being cellulose it is flammable and absorbs humidity.  

Another product of natural origin is represented by perlite, an effusive volcanic rock which, by virtue of the water content contained in, it can expand up to 20 times its volume if it is brought to high temperatures. Its insulating power is very high and by virtue of its grainy composition it is easily usable for blowing into the walls.

Granular cork
Even cork in the granular state is an excellent solution for blowing into the walls and guaranteeing the insulation of the building. Has probably the highest insulating and acoustic power but it has the disadvantage of having a very high cost so that insuring the insulation of a building or even an apartment can involve a fairly high expense.

Granular vermiculite
Vermiculite is a mineral that derives from the alteration of mica and comes in the form of small flakes or crystals, which is why it is very easy to use for blowing the walls. Like perlite, it features a small water content which brought to high temperatures ensures the expansion of the mineral.

Expanded polystyrene in pearls
This product falls into the category of synthetic thermal insulators and is essentially made of expanded polystyrene with a pearl structure that can be used for blowing the walls, also thanks to its excellent insulating capacity and at a decidedly low cost.

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