There are many below-grade waterproofing products on the market. Most manufacturers require you to become a certified applicator before they will guarantee an installation. Different products have very different characteristics, so only specialty water- proofing contractors should try working with multiple products:
- Liquid membranes: Liquid coatings have the advantages of quick application, low in-place cost, and excellent elongation. One of the chief disadvantages is the possible inconsistency in coverage.
- Sheet membranes: A chief advantage of sheet membrane is their consistent thickness. These membranes also have good elongation. A higher in-place cost is one of the main disadvantages of sheets.
- Cementitious waterproofing: Cementitious products are readily available from suppliers of masonry products, and they're easy to mix and apply. The chief disadvantage is that cementitious products have no give to them. They will stand up fine to a head of water, but will tolerate almost no joint or crack movement.
- Built-up systems: This is a good system with a lot of strength, but probably not much elongation ability.
- Bentonite: Bentonite is safe to work with, non-polluting, easy and quick to apply, and can go on even at low temperatures.