Our house was completed in Jan 2004. Currently there is moisture rising in the plaster at ground level. A first expert noted a high humidity on the internal walls of the crawl space. A second expert, without investigating the crawl space, attributes these traces to splashing rainwater. A third detected a high humidity on the external walls and deduced that this was due to capillary rise from groundwater. The buried walls are not protected by a Delta MS and no drain has been laid. What can be done to solve this problem in front of 3 different opinions: Lay drains? Inject resin?... What did the DTU provide? Are there sites free to access?
This is probably the 2nd expert who is in the right (with all reservations, of course, in the absence of a visual inspection on site). To prevent this type of problem, the rules of construction recommend a horizontal waterproof cut installed throughout the walls called "capillary break". This seal must be positioned 15 cm above the ground, it is composed of bitumen felt or mortar including a water-repellent product. In addition it is advisable to double the buried walls of a bituminous coating or a polyethylene foil (Delta MS). A hydrophobic coating in two or three layers on your wall also provides a waterproof barrier to the passage of water.
For more information, consult the excellent SHEET on the basement humidity of buildings, the AQC, the Quality Construction Agency.
The application of DTUs (which are unfortunately not freely available without payment...), is actually an agreement between the owner (you) and the contractor or the builder. A DTU therefore only binds the signatories. It would be necessary to check what was stipulated during the contract of construction of the house to possibly turn against the contractor or the manufacturer if he did not fulfill his obligations.
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