You may find that some of your stairs work loose from their fittings over time.
How To Fix Creaking Stairs From Below
The way you fix creaking stairs really depends on whether you’re able to repair them from below or above. It’s worth checking if you need to take some plaster off before getting at them from underneath.
Start by identifying any loose steps. Get someone to walk up the stairs while you listend from underneath, and then mark any you find with some chalk. If the tread or riser has become loose in its string holding, the glued wedge, that secures the joint, might have worked its way loose. If this is the case, simple remove the wedge, give it a clean, squeexe on some PVA wood adhesive and then replace it.
Check the triangular blocks that fit in the angle between the treads and the risers. If they’re not glued on securely, remove them and scrape off the old adhesive. These prise open the tread/riser joint slightly and inject some glue.
Then apply adhesive to the block and press or screw it in place. If you discover that no blocks were fitted to the stairs, make some, glue and screw them I place.
If you need to strengthen the joint between the back of a tread and the bottom of a riser, squeeze some PVA glue into the gap. Then drive three evenly-spaced screws up through the tread and into the edge of the riser.
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