How to replace a rotten window frame

Damp or exposure to the elements can cause wood all sorts of problems. A rotten window frame is just one of the problems you might come across. Read our guide on how to replace a rotten window frame here.

Level of difficulty

Level 2: Intermediate

What you need

  • Goggles
  • Gloves
  • Dust mask
  • Saw
  • Power drill
  • Screwdriver
  • Screws
  • Putty
  • Wood preserver

The steps to follow

  1. Remove the windows.
  2. Cut through the paint and plaster between the sash and window casing.
  3. Saw through the side frame of the window (jambs) at a 45 degree angle, so that the two ends won't bind when levering out.
  4. Lever the frame with a crowbar, pull the jambs towards you and move them until they loosen.
  5. Saw through the sill at a 45 degree angle. Insert a crowbar under the sill and lever it upward to break free.
  6. Follow the same procedure to remove the head of the frame.
  7. Put the new frame into the opening.
  8. Wedge the sill. Use a spirit level to check if the sill is levelled before securing it.
  9. Attach the sill and jambs with bituminous felt.
  10. Fit the frame into the brickwork and drill 3 holes into each jamb.
  11. Remove the frame and use frame fixings.
  12. Screw the frame back in place.
  13. Fill any gaps with putty and paint the new frame with wood preserver.
Please note that all our DIY guides and 'Expert answers' advice have been written strictly for reference only. Rated People do not accept any liability for any damage caused to an individual, property or anything else as a result of following our DIY guides and using our 'Expert answers' advice.