Regrading Against a Foundation: Waterproofing the Exposed Wall First

You're adding fill against an exposed foundation. The buried portion has a black tar coating. Should you waterproof the newly exposed section? What's that coating called? Can you DIY?

The Black Coating: Asphaltic Mastic (Dampproofing)

Not waterproofing—dampproofing. Stops vapor, not liquid pressure. If your regrading raises grade above the original coating line, you must extend protection.

DIY Options

• Brush-on asphalt emulsion (Quikrete #102612 at Lowe's) – small areas, <200 sq ft.
• Peel-and-stick membrane (Grace Ice & Water Shield, Blueskin) – faster, cleaner, self-sealing around fasteners.
• Sheet membrane + mastic (contractor supply) – larger jobs, pro results.

Critical Detail

Protection must extend 4" above final grade. Not to the old line—to the new line.

Application

1. Clean wall: wire brush, pressure wash, dry.
2. Prime if product requires.
3. Apply per spec (usually 2 coats brush-on, or single sheet).
4. Protect during backfill: dimple board or 1" rigid foam over membrane.

Removing failed mastic later is a nightmare (solvents, scraping). Do it right once.