Is it durable/applicable if I make a 3" tick stair treads out of dry construction 2x12 lumber as 1½" core glued to ¾" hardwood (red oak or finer spicy) all way around? What will be the challenges? In term of wood movement what is matters and need to be considered? To get a more natural look I am thinking of edge bending on front to top faces. The weights will carry by a mono steel stringer linked by a long metal bracket.(no risers) The tread width should be 3'2”. In term of my experience and tools, this will be my first hardwood project! and I am thinking about purchasing 12” thickness planer and electric hand planer. Already have the sliding compound miter saw and table saw. Somebody will make the stringer and the brackets for me.

The 2x12 spf lumber tend to bow and I saw that on 20% of the old treads that I removed. I'm thinking of using 11 peaces of altered grain direction 2¼x1½x38" and one 2¼ x ½ x38" for the core(base) instead of on solid 2x12 and cover it with ¾" hardwood on top and face and veneer on other faces

Appreciate your thought and experience.

  • 1
    mono steel stringer and no risers makes it sound like this will be sort of free-standing or open underneath- won't the construction lumber be visible from behind/under your steps in this case? Commented Mar 24, 2021 at 13:16
  • 1
    "I am thinking of edge bending on front" Please tell me that's a typo for "edge banding" and you're not considering bending 3/4" stock!
    – FreeMan
    Commented Mar 24, 2021 at 13:19
  • When building treads out of SPF lumber I make several partial-depth rip cuts on the underside. This nearly eliminates crowning. That said, I'm not sure what your question is here. We're not a discussion forum, so you need to ask something specific.
    – isherwood
    Commented Mar 24, 2021 at 13:22
  • The ¾ hardwood go all around the SPF. That's how I make 3" tread. The spf lumber has a 1.5" thickness. Adding 3/4 hardwood on top and 3/4 hardwood and bottom cover the lumber and make the 3-in thickness tread for me. Will do the same thing on left and rights. That's going to be a lot of miter cut.
    – Vafa
    Commented Mar 24, 2021 at 14:30
  • @freeman, my mistakes. Definitely not gonna bind that. Actually I meant miter edge!
    – Vafa
    Commented Mar 24, 2021 at 15:08

1 Answer 1


Wood movement is an important consideration and it's good to know you're thinking about it now and not trying to fix it after the fact.

Wood tends to expand the most across the width of a board and not so much across the thickness. This means that your 11-1/2" (or so) wide tread will tend to get wider, pushing the nose of the tread farther out in the "overhang the riser below" position, but won't vary in thickness very much at all. To accommodate this, you'll need to attach your different woods together carefully and design the attachments to the treads carefully, too.

When it comes to attaching the top & bottom hardwood to the construction lumber, you want to have any fasteners in a single row to allow the different woods to expand independently. Your SPF tread core will expand differently than whatever hardwood you choose for the surface. Also, unless you're getting your 3/4" veneer from the same board, your veneers will all expand at slightly different rates, as will the SPF tread cores. Wood is a natural product and no two boards are exactly the same.

Attaching the veneer top to the core at only one point to allow for expansion gives you the possibility that the top will curl and that will be a trip hazard. Quarter or rift-sawn lumber will significantly reduce the likelihood of warping and, for a mission critical portion of the project like a stair tread, is going to be a much less expensive upgrade than the hospital bills or lawsuit from a tumble down the stairs.

A thin veneer of wood (I believe that 1/32" to 1/16" is normal for a commercially purchased veneer, some may be even thinner) shouldn't impact your wood expansion much and it should be attached with normal contact-cement-based veneering methods.

Your update to indicate that you're planning on resawing and laminating the stair core portion will help reduce cupping, but still won't impact expansion. I'm not exactly sure where the "11 pieces of..." lumber will each go, but I'd suggest that 2 or 3 pieces per tread†† with alternating growth ring patterns should be sufficient to significantly reduce potential for cupping.

To attach the treads to the stringers, I'm envisioning some sort of plate with screw holes welded to the metal stringer section(s). If you have a single row of screw holes, then simple round, countersunk holes will allow the wood to expand on both sides of the screw and should eliminate any splitting issues due to expansion. If you do this, be sure to install the treads away from the stringer's risers to allow the wood to expand and fill the gap. I cannot tell you how much expansion room to leave, but you can find wood expansion tables online and they should serve as a good guide. Remember, each piece of wood is unique and these are guides only, not guarantees.

If you're planning on a square of holes, make sure that the screw holes are elongated into ovals so that when you drive the screws through them, the screws can move in the oval slots as the wood expands and contracts. You want the screws to be tight enough to hold the tread securely, but not so tight that the screw cannot move at all. Overly tight will cause the tread to split where the screw is as the wood tries to expand.

An 11-1/2" deep tread (nominal 2x12 construction lumber) is extremely deep and possibly a violation of building codes. Please make sure that this is acceptable to your local building inspector before investing a lot of money in this lovely sounding custom staircase only to have to scrap the whole thing because it doesn't meet with the inspector's approval.

††Make sure you use plenty of glue and plenty of clamps and plenty of clamp pressure when gluing these up. Check out Woodworking.SE for loads of Q&A's on doing glue ups to see just how many clamps are necessary to get a good glue up.

  • Thank you very much for all tips and advises. I will definitely re-think building the tread based on your advice.
    – Vafa
    Commented Mar 24, 2021 at 16:33
  • Different expansion rates are probably one of the reasons treads like this are usually cut from single, thick, expensive blocks of wood, not laminated together. You might consider laminating plywood, then putting a veneer surface on it. You could probably get away with a thin, true veneer for the bottoms and edges, but would probably want a thicker piece to handle wear for the top tread, but then you run into expansion issues again.
    – FreeMan
    Commented Mar 24, 2021 at 17:10
  • Building code in texas doesn't mention anything about maximum tread depth. 11 inches deep minimum is what is asked for. I will check the official source before making it.
    – Vafa
    Commented Mar 25, 2021 at 4:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.