Mending a Broken Stair Tread
Mending a Broken Stair Tread
Stairs suffer inevitable wear and tear but they usually remain structurally sound for a very long time. However, if a broken tread is suspected it should be repaired immediately to avoid a potentially serious accident. Replacing a stair tread is an easy enough job for the average DIY enthusiast, but if the fault looks more serious you may need to consult a professional builder.
There are several methods of repairing broken stair treads, but even the simplest will require access to the underside of the stairs. Stairs fitted with spandrel panelling are easy to repair because the underside is readily accessible. For newer stairs that have been blocked in you may have to remove board to gain access and refit it afterwards.
When workingon stairs, tie a ribbon or a bright piece of tape across the top and bottom of the staircase to preverr itpreventused. A nasty accident could occur if someone were to put their foot where a tread is missing.
Tools for the Job:
- tape measure & pencil
- cordless drill/driver
- wood chisel
- claw hammer
- rubber mallet
If the stair tread is split along its length a quick repair is toand a patch to the underside. Cut this from 9mm (7/16in) ply, making it as large as possible to keep it just clear of blocks and wedges.
Replacing the Tread
Two methods are used to join treads to risers. Some stairs employ a simple butt joint reinforced into the riser to hold the tread secure. The other, more common, approach is for the riser to be tongued or housed into the tread. To check which type you have, try to insert a hacksaw blade between the tread and riser joint. If you cannot work it through than you have the latter type of joint, which must be cut before the tread can be removed.
- Prise off the moulding fitted under the nosing with a wood chisel. Keep the nosing for refitting later. Pull out any left behind.
- From the underside of the stairs use a chisel and mallet to remove any blocks fitted into the corner of the joint between tread and string. Do not try to save these as new ones will have to be fitted later.
- Drill three or four small holes of about 3mm (1/8in) diameter into the riser and through to the tread joint below the damaged tread – these will enable you to insert the blade of a padsaw. Start making the cut with the padsaw, then when it is long enough use a panel saw to finish off the cut, keeping the blade flat to the underside of the tread. Employ the same procedure to saw through the joint between the tread and the next riser, which you will need to do from quick fix under the stairs. Again, make sure that you keep the saw blade flat on the surface of the stair tread.
- Chisel out the wedges that hold the tread in place. If your staircase is of the closed string variety, free the tread by giving it a sharp tap with a hammer and block of wood right above and adjacent to the string. With the tread free, drive out to the rear again by tapping the nosing with a block of wood and hammer.
- If you have an open string staircase the approach is slightly different. Prise off the return moulding on the end of the tread, then remove the balusters by tapping them side ways from the shallow mortises before knocking out the tread from the rear.
- Cut a replacement tread from timber, using the old tread as a template for the new one. Ensure that the timber has the same dimensions as the existing tread and that the nosing is identical to the original, otherwise it will not fit correctly.
- Refit the tread following the same procedure for removing it, only in reverse. Cut new wedges and glue blocks, coat these with , then fit by tapping the wedges firmly home. Finally, replace the balusters and return moulding and Scotia moulding if it was removed earlier.
Tips of the trade
If your staircase is old or there is any evidence of infestation or rot, both new and old timber must be treated with a suitable preservative before sealing in the underside of the stairs.