How to Deal With Shrinking Caulk

Designed to seal gaps in siding, doors and windows, caulking is applied to exterior building joints to create a weather-tight seal. In addition to preventing moisture infiltration, caulking also provides insulation and helps control noise. When not protected by paint, some types of caulking are highly susceptible to drying out, causing the caulking to shrink and pull away from the edges of the joint. Once seal integrity becomes compromised, caulking must be repaired or replaced before water damage occurs.

Paint scraper or putty knife
150-grit sandpaper
Caulk
Utility knife
Caulking gun
Nail
Cloth

Instructions

- 1
  Examine exterior building joints. If caulking shows signs of cracking, as well as shrinkage, the caulking must be removed. If the caulking is only pulling away from the edges of the joints, as a result of shrinkage, fill in the spaces with new caulking.
- 2
  Scrape cracked caulking from the surface with a paint scraper or putty knife and sand the area with 150-grit sandpaper.
- 3
  Select a paintable caulk approved for exterior applications; choose a clear silicone based caulking for surfaces that will not be painted.
- 4
  Insert the tube of caulking into a caulking gun. Cut off the tip of the caulking tube at the 1/4-inch bead marking with a utility knife. Insert a nail into the tip of the caulking gun to puncture the foil seal at the base of the nozzle.
- 5
  Place the tip of the caulking tube against the joint -- or the space between the existing caulking and the joint. Pull the trigger of the caulking gun while moving the tip of the caulking tube along the space in a smooth, steady motion. Wipe off excessive caulking from the edges of the joint with a damp cloth.
- 6
  Allow the caulking to dry according to the manufacturer’s instructions before painting.

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