Replacing wood stair treads can be simple, very complicated, or nearly impossible depending on the construction of your stairs. Providing a definitive answer for how to fix wood stair treads is difficult because there are literally hundreds of scenarios with respect to how the stair was constructed, and newel and baluster placement. This article will go over your options for replacing stair tread in the most common construction types, to help you determine the best way to fix your wooden stair tread.
Step 1- Determine Newel and Baluster Placement
The first thing you need to do is examine your stairs and determine if the newel post actually sits on top of the stair tread or if the tread itself is notched to accommodate the newel post. If your tread was notched around the newel post, lucky you. You have the easiest type of stairs to remove a tread from. If the newel post sits on top of the tread, then you will need to remove the newel post before you can remove the stair tread to work on it. Newel posts can be anchored in a variety of different ways. Unfortunately many are mounted from the inside of the stringer, making it almost impossible to remove it without access to the underside of the staircase. A similar situation applies to balusters. They may be mounted using dowels through the stair treads and up into the baluster. They may be dovetailed into position with a piece of wood covering the edge of the stair treads, hiding the dovetail. The stair treads could also be mortised into position. Mortised means a square hole has been put in the stair treads to accept the base of the baluster.
Step 2- Remove Trim, Newel Posts and Balusters
Now that you know what you are up against regarding the newel posts and balusters, you need to get started on the actual removal process. Using a 7 inch mini pry bar, remove any decorative moldings from around the stair treads and the stringer. Also remove any moldings between the tread and the riser. If you have access to the back of the stairs, do your best to remove the newel posts from that position. If you can't access the back of the stairs, you will need to find some way to remove the balusters and newel posts. You may end up having to cut them out and then replace them after you fix the broken tread. It is drastic, but a well made staircase was never meant to be taken apart.
Step 3- Remove and Replace the Treads
Using the pry bar pry upward between the stair tread and the riser in front of the stair tread. Work the entire front of the stair tread from the edge of one stringer across to the other, lifting in a maximum of 1/8 inch increments as you go along the front of the stair tread. Now, it is possible that the riser has been screwed horizontally into the stair tread on the back side of the tread on the underside of the staircase and/or that triangular blocks have been mounted between the stair treads and the stair risers. If that is the case, then it will be almost impossible for you to remove the tread without having access to the back of the stairs. If this is what you are up against, then you may need to take the step of cutting the tread and riser out. If you decide to do this, make sure that you take precise measurements of the remaining treads and risers so that you can have pieces cut to the same size to replace them. Replace the broken stair tread and attach to the stringer with construction adhesive and nails or screws.