How to Fix Cracks in Window Casings

A window casing is the frame that surrounds the window both inside and outside. Cracks in exterior window casing or gaps between the siding or brick of the house and the wood are common. They form as the sun, wind and rain cause the wood to expand and contract. Unless the crack is accompanied by signs of rot such as mold and mildew or sponginess in the wood, you can patch most cracks without removing or replacing the window casing.

Sponge
Water
Dish soap
Wood putty
Putty knife
Exterior paintable latex caulk
Fine-grit sandpaper
Paint

Instructions

- 1
  Remove dirt and grime from the casing using a damp sponge or cloth. Wipe the area thoroughly to make sure there are no loose particles stuck inside the crack. For stuck-on grime or mildew, use a mixture of a few drops of liquid dish soap and warm water.
- 2
  Allow the wood to dry completely before beginning your repair to ensure that you don’t trap moisture within the wood when you patch the crack.
- 3
  Apply wood putty into the cracks in the window casing using a putty knife. Press the putty into the crack and wipe the excess away.
- 4
  Continue applying putty into the crack and pressing it in with the putty knife until the putty completely fills the crack and there are no pockets of air.
- 5
  Inspect the window casing where the wood meets the wall. Occasionally the elements can cause the wood to warm, and this may leave a gap between the wood and the wall that should be sealed. If you find gaps, clean away dust and debris with a damp cloth.
- 6
  Allow the casing to dry completely and then fill the gaps with a bead of exterior paintable latex caulk.
- 7
  Press the caulk into the gap with a putty knife. Make sure the caulk fully fills the gaps. Reapply and smooth again if necessary.
- 8
  Smooth the caulked areas with a putty knife a final time so that the caulk is flush with the edge of the casing.
- 9
  Leave the putty and caulk to dry completely. Drying times vary depending on the weather and temperatures, but usually about two hours is sufficient.
- 10
  Smooth the cracks filled with wood putty with fine-grit sandpaper until the patched areas are flat and blend in with the casing.
- 11
  Wipe any dust remaining from sanding with a dry cloth and paint the patched areas to match the rest of the casing.

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