I am replacing my carpeted stairs, 13 in all, with red oak. I’ve milled and glued up flatsawn treads as 3/4″ thick x 10″ wide x 40″ long. Because the stairs were carpeted, the risers are sheathed with 3/4″ ply. I have no access to the underside of the stairs and would like to prefinish them because I need daily access to the second floor. So- my plan is to use construction adhesive like PL premium and 13/8″ pins to secure the treads. Because my treads are so thin, I fear they’ll flex and squeak unless I snake a line of adhesive under the entire tread. However, then I fear the treads will crack as the wood expands with the seasons. Is there enough flex in PL premium or similar construction adhesives to allow expansion while keeping the treads secure? Has anyone had any luck using just construction adhesive? Other options?
– Lyptus
Replies
In the past, I've had issues with using construction adhesive on treads glued to a substrate but mostly with wider treads, landings and winders. The solid wood moves but the substrate doesn't. This can result in the solid wood splitting. Construction adhesive doesn't have any flex once set up. Gluing two materials together that have different possibilities for expansion is a well known potential problem in the furniture and cabinetmaking world.
I like trim head screws for securing treads. I use 9 screws per tread, three on each stringer. On pre-finished material, you can use color putty to fill the small holes but it should have another coat of finish over the filler. Normally, you have access to the stringers and can add shims if the treads don't fit tight against the stringer "teeth". Avoiding squeeks will depend on how well the treads fit to the existing plywood in your case, although, the screws should pull all but the extreme misfit tightly. Most squeeks are from the tread rubbing on skirts or risers. Screws will hold much better than nails and should keep treads from moving or working loose. Of course the entire carriage may be subject to movement, particularly through seasonal humidity changes. I'm in a six month winter area, so long heating seasons dries wood out and causes shrinkage. I don't get tread squeeks but I may get a groan from the entire assembly now and then, since the entire house moves a little.
Yeah, trim screws were my thought.
But how will trim screws allow for wood movement? Do you make pilot holes in the treads larger than the screw diameter?
Nails and thin shank screws won't restrict the small movement. You don't have to drill larger holes.
Trim Screws
Trim screws & adhesive to eliminate squeeks, no pre-drilling necessary: http://www.screwsolutions.com/Bronze-Star-Trim-Head-Finish-Star-Drive-Screws_c_30.html