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Sanitary space in a new house: advantages in the South-West

Construction of a wooden house on South West crawl space

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A time forsaken for buildings on solid ground, the crawl space in new house finds today its letters of nobility. It must be said that it does not lack assets, since it participates in the creation of a healthy home, comfortable and durable. Thermal comfort, moisture control and termites, adaptation to the terrain… Discover its many advantages.

What is a new home crawl space?

The crawl space is an empty space located under the low floor of a house, between the natural ground and the concrete slab which supports the structure of the construction. The floor is then placed above the ground. Its height varies between 0,20 and 1,80 meters.
The other solution would be to build the concrete slab directly on the ground. Although this technique is particularly simple, it is not suitable for all terrains. And today the construction on crawl space is becoming more frequent, because it responds to many constraints.

model of a house crawl space
Construction principle of the crawl space in a new house built by the builder Sic Houses. Sanitary space with basement 3 rows of concrete blocks or more and insulating slab floor.

Limit rising damp

One of the greatest advantages of a crawl space in a new home is its moisture protection the capillary rise are a real calamity in a house. This problem is related to the humidity contained in the ground which is gradually absorbed by the materials and seeps into the house. This phenomenon is difficult to stem and the humidity in the walls of the house is the cause of damage (insulation, woodwork, paints, coatings, etc.), and the appearance of molds and other more formidable fungi in housing. Ventilated, the crawl space allows the absorbed water to evaporate before it reaches the interior of the house.

Crawl spaces in new homes: an all-terrain solution

The crawl space makes it possible to build on all types of land, whatever their nature or their gradient. In the South West, many terrains are subject to risk of shrinkage swelling of clays. The constructive solution chosen by the builder houses Sic aims to reduce the risks of these difficult terrains as much as possible. THE crawlspace separates the floor from the ground to avoid risks of settlement or soil movement as a function of humidity (clay soil). This construction method, which is so suitable for sloping land, than to those consisting of embankments, makes it possible to adapt to all floor configurations.

To find out how to build on difficult ground, read our article » Soil study: stage 1 of a sustainable house in the South-West"

The thermal comfort of a raised floor

Do you know that the better insulator is the air? THE crawlspace is a buffer zone between the ground and the house. It thus naturally insulates the floor of the house, but must be supplemented by a thermal insulator. The crawl space is a practical solution that allows the implementation of various thermal insulation processes, since the slab can be insulated both internally and externally. The choice ofbottom floor insulation will therefore be made according to the constructive choices or the heating system chosen by the customer.

Map illustrating areas with high radon potential in the South-West.

To learn more about the importance of insulation, read our article: 5 questions to understand the insulation of the new house"

A crawl space in a new house to protect against radon

Where is there radon in the Southwest?

Do you know that we may be exposed to radioactivity of natural origin? THE radon is a colorless and odorless radioactive gas that can be emitted from rocks in the ground. It is considered in France as the second leading cause of death from lung cancer after tobacco. In the South West, its frequency is lower than in other French regions such as Brittany or the Massif Central. Nevertheless, this risk is clearly identified in the Pyrenees, the South of Arcachon bay,Aveyron, Tarn and various scattered municipalities.

How to build a house without radon in the South-West?

To eliminate radon of the dwelling, it must be prevented from penetrating inside the building and evacuated. THE crawlspace then turns out to be a good constructive solution since it limits the surface in contact with the ground of low floors. THE basement of a house subject to radon emissions must also be well ventilated to prevent the accumulation of radon. The regulations governing the construction of new houses, the RE2020, by chasing down heat loss also makes it possible to fight against radon, since it requires airtight houses and perfectly well ventilated. All these tips will also contribute to the good quality of the air in the home.

To know the radon potential of your municipality visit the IRSN website.


Limit damage during flooding

Similarly, in the event of a flood, water is less likely to reach the interior of the house. Indeed, the crawlspace protects from rising water table which sometimes intervene in the event of heavy rain.
During floods from inside and outside the house, the crawl space allows water to drain more quickly. Walls and floors can dry faster, which reduces the consequences of such inconvenience.


model crawl space ventilation
A ventilation grille allows the crawl space to be ventilated. This solution makes it possible to fight effectively against humidity but also against the accumulation of radon which could then penetrate into the dwelling.

The crawl space: less damage in a new house

Separated from the ground, the floor places its loads on the foundations through the facade walls and other load-bearing walls. The depth of the foundations was determined by soil study. These rest on a hard ground to secure the construction over time.
If the ground moves, the house remains stable. There is therefore no risk of seeing the pipes break since the paving and the exterior walls are united and protected from the movement of the ground.


termite presence in the southwest map
Le great south-west is particularly affected by termites. The crawl space is a solution to protect the house.

A crawl space to protect against termites

Le great south-west is heavily infested with termites. While termites appreciate confined, humid atmospheres, a well-designed crawl space provides good ventilation to the area and avoids humidity. without being a anti-termite system, it enables the built-soil interface to be checked regularly. Provided that its height under the floor is sufficient, the occupant of the house will thus inspect the floor, the walls, the underside of the floor and the various spaces which could allow the movement of insects approximately twice a year.


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