Sand Down Swollen Areas

When wood window frames or sashes swell from humidity and bind against each other, sand down the contact points to restore clearance. Perform the sanding during humid weather while the wood is in its swollen state so you remove only the material that actually causes the bind.

Why It Works

Wood absorbs moisture from the air and expands, especially in summer. Sanding while the wood is swollen ensures you take off just enough material. If you sand during dry weather when the wood has contracted, you risk removing too much and creating gaps that let in drafts and rain when the wood shrinks further in winter.

Tips

• Start with 80-grit sandpaper to remove bulk material, then finish with 150-grit for a smooth surface
• Mark the binding spots with chalk or pencil by closing the window and checking where the marks transfer
• Sand in the direction of the wood grain to avoid splintering
• Seal or prime the sanded area afterward to slow future moisture absorption