Window Frame Repair in Boston, MA

A rotted window frame almost never means a new window. We cut out the decayed wood, rebuild or replace the damaged pieces, and seal the window so the water that caused the rot stays out. In the Boston area most frame repairs come in between $145 and $795 per window, against $800 to $2,500 for a replacement window. Frame work is part of our wood window repair service, and we price most jobs by email from photos.

What window frame repair costs

These are real prices from our own work across Greater Boston. They include caulking and painting the new pieces white. If you want the original color, leave us the paint and we use it.

• One piece of rotten trim or casing, replaced in PVC: $145. In wood: $125.

• Both side pieces: $290. Both sides plus the top: $375 to $435.

• Header or crown molding: $365.

• Rotten sill replaced in PVC, caulked and painted: $345. Exterior sill: $395. Interior sill: $225 to $345. Rounded sill: $795.

• Rotten bottom of the sash (the moving part of the window): $495 to $695.

• Sash rot repair with painting: $495 to $795 per sash.

• Wood casement with a rotted bottom: usually $595 per sash, up to $995 if the side of the sash has rotted as well.

There is no deposit for sills and trim, and the work is usually done in a single visit because nothing has to be ordered. The assessment visit is free for wood, sill and glass work.

Why frame repair quotes vary so much

Rot always runs further than it looks from outside. Until the failed paint is off, nobody can say for certain whether a window needs one $145 piece of trim or a sill and both sides. That is why we price from photos, confirm the scope on site, and tell you the number before any work starts. If we find more rot once the old wood is open, you hear about it and the price for it before we touch it.

Can I repair a rotted window frame, or do I need a full replacement?

In most Boston-area homes the frame can be repaired. Decay is usually confined to the sill, the bottom of the side jambs and the exterior casing, while the rest of the frame is still sound old-growth wood. That wood is denser and more rot resistant than what goes into a new window, so keeping it is worth it.

Repair stops being the right call when the frame has rotted through completely, or when the rot has moved into the wall framing and siding behind the window. We work on the window, the sill, the casing and the trim, not on house framing or siding. If that is what we find, we tell you plainly instead of selling a repair that will not hold. We repair windows only and do not sell replacements, so the recommendation you get is the one that fits the window.

How do I know if my window frames have wood rot?

Press a screwdriver into the wood at the bottom corners of the frame, where the jamb meets the sill. Sound wood resists. If the tip sinks in under light pressure or the wood crumbles away, that is rot. Check these places first, because this is where water sits:

• The sill, especially where it meets the side jambs

• The bottom corners of the frame and the bottom rail of the sash

• The exterior casing and trim where it meets the siding

• Any spot with a water stain, a dark streak, or paint that blisters and flakes in one place

Other signs: drafts with the window closed and locked, a sash that sticks or no longer sits square, open joints, and paint that fails again a season after it was redone.

How we repair a rotten window frame

1. Photos and a price by email

Send photos of the damage, inside and out, and your address to admin@wholewindow.com. For sills and trim we can usually give you the price straight from the photos.

2. Remove all of the decay

Failed paint and soft wood come out, back to wood that resists the screwdriver. Repairing only up to the visible edge is the most common reason a frame repair fails two years later.

3. Replace or rebuild the damaged pieces

Depending on the damage we use a combination of:

• Replacement pieces: new sills, casing and trim, in PVC or wood, cut to fit the opening

• Wood splicing: a new piece of wood spliced into the sash or frame where only a section is gone

• Epoxy repair: for profiles and corners where a splice is not practical, the remaining fibers are consolidated and the shape is rebuilt

4. Seal it against the next winter

Every joint is caulked and the new pieces are painted, so water has nowhere to get in. Once the frame is sound again, weatherstripping keeps the drafts out as well.

Here is what a finished repair looks like: before and after a rotted wood window restored.

Questions we get about frame rot

How much does window rot repair cost?

Most jobs fall between $145 for a single piece of trim and $795 for a rounded sill or a sash rot repair with painting. A typical sill replacement is $345. See the full price list above.

What is the best filler for wooden window frames?

Standard wood filler is cosmetic. It fills nail holes and shallow defects, it does not bond to soft wood, and packed into a rotted sill it hides the decay while it keeps spreading. A two-part epoxy system is a real repair, but only on dry wood with every bit of rot removed first. Our guide to wood window frame repair covers fillers and do-it-yourself fixes in detail.

How do you replace rotted wood around a window?

The rotted piece of sill, casing or trim is taken off, the wood behind it is checked, and a new piece is cut to fit, fastened, caulked and painted. When the rot is in the window itself, we repair it. When it is in the wall or siding beside the window, the water is coming from the house rather than the window, and that is work for a siding contractor.

Is it worth fixing old wood window frames?

Usually yes. Fixing a rotted sill and trim costs a fraction of a new window, keeps the original profile of the house, and the repaired frame lasts for decades when it is kept painted.

Get a price on your window frame repair

Rotting wood only gets worse over a New England winter, and more expensive to fix. Send photos of the damage to admin@wholewindow.com or call (617) 982-1211. We repair window frames in Boston, Brookline, Newton, Needham, Wellesley, West Roxbury and surrounding towns. Free quotes, 1 year warranty on labor and materials with an optional 5 year extended warranty, Google 5 stars.

We also work in Chestnut Hill, Dedham, Westwood, Norwood, Walpole, Medfield, Dover, Natick, Wayland and Weston.