Injection of polyurethane in air chambers

Improving the insulation of a building by injecting polyurethane in air gaps

When facing the challenge of restoring a house or a building, owners see it as a expenditure of money that will not be recovered and professionals a challenge due to, among other aspects, the great diversity of insulating materials in the market.

It has been shown that one of the most profitable investments that can be made in both new and restoration works is in energy efficiency. The greatest energy expenditure of a home is air conditioning. Can we reduce it?

The objective is difficult, but thanks to a good building insulation we can ensure that most of the year the house will maintain a comfortable temperature for its inhabitants.

To improve the insulation of an existing building, we can consider different options. For almost all of them we will have to carry out major works or reduce the useful space of the housing, the office or the recreational building. However, there is a solution that can offer everything we need, without performing major works: the injection of polyurethane in the existing air gaps.

Before beginning the execution, it is advisable to conduct a feasibility study and to foresee all the problems that may arise during the work. In case that the typology of the wall allows it, and our study is favorable, this measure is one of the most effective for a successful implementation of the new insulation.


Injection of polyurethane in air gaps

To carry out the thermal insulation works by injecting polyurethane into the air gaps, a series of holes must be made in the interior walls. These shall be located in such a way that there is no more than one meter of distance between one and the other. They can not be aligned in a grid, since the diagonals would produce a greater distance than the one recommended.

We will then insert polyurethane foam through these holes. It will be done from bottom to top, allowing a correct filling of the air gap. There will be a slow expansion, which will completely fill the chamber while adapting to the interior surfaces. Once this is done, we will proceed to the closing of the holes and to give uniformity to the walls. As it is a rigid material that fills all holes and cracks, it helps to improve the structural stability of the partition.

Injected polyurethane foam reduces the thermal conductivity of the enclosures by 8 times compared to air. The injection of polyurethane in the air chambers improves the thermal behavior, and consequently the comfort of the house, while increasing the level of acoustic insulation, too.