Rotten sash
- Cause
- Standing water at the bottom rail and failed paint film.
- Correction
- Decayed sections are cut back to sound wood and scarfed with matched species stock.
Knowledge Center
Common problems, and what they actually mean.
Most window complaints trace back to a small number of physical causes. Identifying the cause correctly is what separates a targeted repair from an unnecessary replacement.
Advanced rail decay. Visible failure of this kind is almost always preceded by years of finish-film cracking that went unaddressed.
Rotten frame
- Cause
- Sill slope loss, failed flashing, or sealant separation at the jamb.
- Correction
- Sill and jamb sections are replaced in place, then primed on all six sides before reinstallation.
Failed insulated glass
- Cause
- Perimeter seal fatigue lets the sealed cavity breathe.
- Correction
- New warm-edge, argon-filled Low-E unit set on fresh setting blocks.
Foggy windows
- Cause
- Moisture condensing between panes after seal failure.
- Correction
- Glass replacement only — the sash and frame are typically fine.
Broken glazing
- Cause
- Putty or bead shrinkage and UV degradation.
- Correction
- Full re-glaze with a compatible bedding compound and new bead.
Loose joints
- Cause
- Seasonal movement breaking down original glue lines.
- Correction
- Sash is disassembled, cleaned, re-glued, and clamped square.
Water intrusion
- Cause
- Blocked weeps, reverse-sloped sills, or missing pan flashing.
- Correction
- Drainage path rebuilt, weeps cleared, sill re-pitched.
Paint failure
- Cause
- Moisture driving from behind the film, or incompatible coatings.
- Correction
- Strip to sound substrate, consolidate, prime, and finish with a breathable system.
Wood decay
- Cause
- Sustained moisture above roughly 20 percent content.
- Correction
- Consolidant for early decay; milled replacement for structural loss.
Drafts
- Cause
- Compressed weatherstrip and out-of-adjustment hardware.
- Correction
- New seals plus hardware adjustment to restore compression.
Broken hardware
- Cause
- Corrosion and cycle fatigue in operators and hinges.
- Correction
- Rebuild or replace with matched or upgraded components.