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Ink Slinger
158 Posts
What is the difference between Damp proofing and waterproofing?
The thing they have in common is that the wall has earth against it on one side and enclosed space on the other.

Waterproofing is required where there is a high water table or reason to believe that wet soil conditions will exist.

We tried to waterproof even where damproof was called for. You never know what the future holds.

irc 09 dampproof
1. Bituminous coating.
2. Three pounds per square yard (1.63 kg/m2) of acrylic modified cement.
3. One-eighth inch (3.2 mm) coat of surface-bonding cement complying with ASTM C 887.
4. Any material permitted for waterproofing in Section R406.2.
5. Other approved methods or materials.

irc 09 waterproof
1. Two-ply hot-mopped felts.
2. Fifty five pound (25 kg) roll roofing.
3. Six-mil (0.15 mm) polyvinyl chloride.
4. Six-mil (0.15 mm) polyethylene.
5. Forty-mil (1 mm) polymer-modified asphalt.
6. Sixty-mil (1.5 mm) flexible polymer cement.
7. One-eighth inch (3 mm) cement-based, fiber-reinforced, waterproof coating.
8. Sixty-mil (0.22 mm) solvent-free liquid-applied synthetic rubber.

We still never refered to a wall or foundation as waterproof even if we followed waterproofing protocol

General Contractor
8,210 Posts
As Timo said the differences between code requirements... In addition Damp-proofing is intended to keep the moisture from the soil from penetrating foundation and waterproofing is intended to keeps water and the moisture from penetrating foundation.

On the general note, if you have a well done foundation with perimeter drain, proper grading and for as long as you have your floor elevation about 1' above seasonal water table and the soil conditions which more or less have good drainage properties, which prevent Hydrostatic pressure, damp-proofing can provide long term protection.

I'm a Mac
5,487 Posts
You specify Damproofing in your contracts scope of work, the customers lawyer will try to enforce Waterproofing, you fight for the words Damproofing because if it ever leaks and you had Waterproofing in your contract you maybe paying
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