Check Interior Windows for Seal Failure
Why It Matters
Windows with failed seals lose their insulating value, increasing energy costs and allowing moisture that can damage window frames.
Quick Guide
- 1
Gather your tools and materials
You'll need: basic tools. Materials required: necessary materials.
- 2
Perform the check interior windows for seal failure
Look for condensation or fogging between double-pane window glass, which indicates seal failure.
- 3
Verify and clean up
Check that the work was completed correctly and clean up your workspace. If failed seals require glass replacement, consider calling a professional.
Community Tips
Examine the glazing compound (putty) around single-pane windows for cracking or shrinkage, as this is the first line of defense against air infiltration and moisture. If the putty crumbles when touched or shows gaps wider than 1/8 inch, it's failed and must be replaced with fresh compound like Sarco Putty ($6-12), which cures harder and resists weathering better than hardware-store generics.
Never ignore condensation trapped *between* panes on dual-pane windows, as this indicates the hermetic seal has already failed and the insulating gas has escaped. Attempting to re-seal these windows is ineffective; the unit must be replaced entirely to restore energy efficiency and prevent mold growth inside the cavity.
Interior caulking around window frames costs $8-15 per window in materials (using GE Silpruf or Tremco Polyurethane, $12-18 per cartridge), but sealing gaps under 1/4 inch prevents condensation damage worth hundreds in drywall repairs and can reduce heating costs by 5-10% on older homes with poor seals. ---