Fixing sticking, rattling and painted-shut sash windows
A double-hung window that will not move is almost always a paint, cord or swelling problem, and those are the most routine repairs in older Philadelphia houses.
What holds a wood sash window together
A traditional double-hung window has two sashes that ride in channels on the sides of the frame. Hidden in the frame, a cast iron weight on each side is tied to the sash by a rope called a sash cord, running over a small pulley at the top. When a cord snaps, the sash drops or sits heavy and the window will not stay open.
Many rowhouse windows have been painted many times. Each coat narrows the gap the sash needs, which is why a window that moved easily when new now sticks hard in summer humidity.
Repairs, from simple to involved
- Free the paint sealA thin blade scores the paint line at the stops and the meeting rail so the sash can move. The channels are then sanded and waxed.
- Replace the sash cordsThe stop strip is removed, the broken cord is replaced with new cord or chain, and the weight is rehung so the sash balances.
- Fit new weatherstrippingBronze or vinyl strips along the sides and meeting rail stop rattling and cut air leaks while leaving the wood windows in place.
- Rebuild a loose jointWhere a sash has racked, a repair carpenter squares it, re-glues the joint and adds fasteners.
What is different in Philadelphia houses
- Narrow interior rowhouses
- Many rowhouses have a window in the front and rear of each floor only. Workers often bring sash and weights out through the opening or through the house, so ask how the installer will protect floors and finishes.
- Lead paint before 1978
- Scraping and sanding old paint can create lead dust. In a house built before 1978, EPA's Renovation, Repair and Painting rule calls for certified firms using lead-safe practices.
- Properties under Historical Commission review
- If the house is on the Philadelphia Register of Historic Places, keeping the original wood sash and its pattern, such as six panes over six, is the approach the Commission tends to favor, so repair is often the easier path to approval.
When freeing a sash is not enough
If the bottom rail is soft, the meeting rail has split or the frame has pulled away from the brick, the repair moves from adjustment to carpentry. Read the guide on rot and glazing repair next, and ask for the condition of each window to be written down before you compare estimates.
Keep reading on this site
Rot, glass and glazing
What can be patched, what must be rebuilt, and how glass is reset.
Storm windows and weatherstripping
Comfort upgrades that leave the original sash in place.
Window repair in Society Hill and Old City
Historic townhouse sash, Commission review and lead-safe repair.
Window repair in South Philadelphia
Block-long brick rows, shared walls and old sash.
Questions people ask
Why does my window stay open only when I prop it?
That usually means a broken sash cord or a missing weight. The fix is to open the side of the frame, reattach a cord to the weight and sash, and test the balance.
Can I paint over a sticking window to fix it?
No. Another coat of paint narrows the gap more. The paint seal needs to be cut and the channel cleaned, then painted with the sash slightly open so the coats do not bond.
Do rope and weights have to be replaced with something modern?
No. Many installers re-cord windows with the original style of weights. Spring balances exist but are mostly used where the weights are missing or the pocket cannot be reached.