Foundation & sill plate

1·2·3 How to apply it

1. Walk the outside perimeter and look for daylight, gaps, crumbling mortar and gnaw marks at the sill line.
2. Brush away cobwebs, soil and loose paint so the surface is dry and sound.
3. Lay a continuous two-inch band of gel along the joint where the framing meets the foundation.
4. Repeat on the inside of the basement or crawl space where the rim joist sits on the sill.

✓ Things to consider

• Early autumn is the moment to do this, before the first cold snap sends everything looking for shelter.
• A four-inch mini roller covers long straight runs quickly; keep a brush for corners.
• Trim back mulch, ivy and shrubs from the foundation first so you can see and reach the line.

✕ Things to avoid

• Do not treat over a gap larger than about a quarter inch. Stuff it with copper mesh or foam first, then coat.
• Do not apply to a wet or frosted surface; wait for a dry day above 40°F.
• Do not coat weep holes in brick veneer. They need to drain.