Moisture in crawl spaces

solved with TONZON Soil Foil


TONZON Soil Foil is a simple and effective way to dry out crawl spaces. This is not only good for piping and hanging brackets under the floor, but also for the floor itself - and effectively prevents a lot of moisture from entering the house. Less moisture in the house means less ventilation is required. And, as a result, less heating. How this works is explained below.



A drier crawl space

The video clearly explains the effect of Soil Foil by TONZON. The first part of the video shows the situation before Soil Foil was applied in the crawl space. The video then shows the ‘after’ situation – two weeks later: Everything above the Soil Foil is bone dry (including the foundation walls), while there is a layer of water under the Soil Foil.

Moisture flows in the crawl space


The ground floor is never completely airtight. Not even with floors fitted in new houses, which fully comply with the requirements of the Building Decree. So air always rises from the crawl space. If the crawl space is damp, that air also carries moisture into the ground-floor rooms. A floor of 60 sq. metres will easily deliver a litre of water per day. In older homes, this can be as much as 10 litres of water a day. Many people then use extra ventilation, by opening a window or using mechanical ventilation.

Mechanical ventilation not only increases energy consumption. It perpetuates the problem, as the ventilation draws in more air from the crawl space and, with it, more water. This water again has to be removed. A vicious cycle that again uses more energy! TONZON Soil Foil has a vapour barrier of 130 metres and thus completely stops the evaporation of moisture from the soil. The air entering the room is therefore dry, with no more moisture entering via the crawl space.

If your crawl space sometimes contains water, a layer of bubble wrap is placed under the Soil Foil. This increases the floating capacity of the Soil Foil and, as a result, creates a drier crawl space.


TONZON Soil Foil


Many homes have been and are still built over a damp depression in the ground. Because of a negative pressure, the house sucks in air from the crawl space. This air contains moisture and radon gas, that escapes from the soil. If the Building Decree standard is met, about 1.3 litres of moisture per day enters the house under standard conditions. This moisture must be removed by means of additional ventilation. TONZON Soil Foil has a vapour barrier of 130 m and a very high radon barrier of D=(9.2±1.6).10¯¹²m²s¯¹. See here for instructions on installing Soil Foil yourself.


Experience the comfort of effective Soil Foil


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