SINCE WHEN IS THE PRESENCE OF A VAPOR BARRIER UNDER THE FLOOR SLABS IN THE BASEMENT MANDATORY?

✅According to the National Building Code (NBC) literature, prior to 1970, basement and cellar floor slabs had to be constructed to resist the passage of water and water vapor, but no specific method was required.

✅Starting with the 1970 NBC, the code introduced the requirement to waterproof slabs using a 6-thousandths-of-an-inch polyethylene vapor barrier installed under the slab (reference: article 9.13.6.1 ).

✅So, if you notice the presence of mold and humidity on your slab due to the absence of a vapor barrier, this situation could be considered as a defect, causing damage related to the requirements of the time, if your residence was built after 1970.