What kind of glue for stairs?

I just finished a stair project in which I replaced all the risers and then installed retread over the old treads. This afternoon, I just finished ripping it all out. I used liquid nails subfloor to glue down the retread. I didn't use more than 1/8" thick glue in places, but apparently that was too much and it caused the retread to warp. Pieces now look as though they were cut from the side of a cylinder. In fact, there was a lot of wet glue still left over when I demoed the retreads.

For my next attempt I place to replace the treads entirely. I hate to replace the 1 1/2" (true) thick pieces, but there's no way I'm gonna try retread again. I'm going to have to rip out the dry wall just to get them out.

Anyway, my question is, what sort of construction adhesive am I supposed to use for stairs? Heavy Duty Liquid Nails said not to use it for flooring. This time around I will also use screws instead of nails. It's my understanding you should only screw into the stringer.

So, what kind of glue?

 

Something that doesn't come out of a tube? I really don't know anything about this or if glue is even necessary. I personally have never seen stair treads glued to the stringers but IF I decided it was necessary I would probably use a resorcinol glue. You will utterly destroy the stairs if you ever have to take them apart, though.

 

PL Premium Adhesive. Are these the retreads that you put over the humped existing treads? Leave the existing treads and remove the hump via planing or sanding or build up the low spots to get a flat surface for the retreads to rest on.

 

JIMMIEN,

Thanks. You were very helpful the first time I tackled this. I go with the PL Premium Adhesive you suggest and this time I'll use the screws instead of the nails as you suggested last time.

I did shim around the humps last time. It took me about 8 hours to do 10 steps. The stairs looked beautiful for about a day and then they all warped up. lol.

I have a belt sander and grinder. It's hard to say what would be more work. The mess of grinding them all perfectly flat or just ripping them out and putting in new treads. Either way, I wouldn't trust the retreads to just warp again so I'm just going to replace the treads. Replacing the treads instead of retreading means I won't need nearly as much glue.

Oh, and this time I'm just going to install it all, then stain and finish. That way I can do it all at once and not have to sand inbetween any coats. Most of all I just don't know if the weather will cooperate this late in the year.

Thanks for your help both last time and this. I wanna puke just thinking about having to do this all again, but that's how it goes sometimes.

 

I agree the original treads need to be perfectly flat! You don't want any voids.

If the retreads are wood-wood and you want complete coverage, use DAP Weldwood Plastic Resin glue. Its a powder you mix up into a liquid, then paint on both sides with a hot dog roller. You don't want a lot to squeeze out, if it does you will want to wipe it off right away before it dries. Its very sandable, but big globs of it dripping out would obviously be a bad thing. It has a long open time, and a reasonable cure time. You would need to maintain pressure on the glue joint to ensure complete contact. The instructions tell you about cure times, and are based on temperature. Generally 4 hr pot life, 12 hr cure. Cure time can be accelerated with heat.

You will not be able to separate the retreads once you glue it with this product. There's a reason they call it Weldwood. This is excellent glue to use when assembling and clamping bent handrails, and will also work well for treads.

If you do wind up removing treads, use a sawzall to cut the treads into pieces, cutting close to the wall. Then use a chisel (perpendicular to the cut) to split the part remaining in the wall into small pieces that will fall off the nails.

 

xsleeper,

Thanks for the response, but I will not be taking another chance on retreads. If I replace the treads I know just what I'm getting into and there's less chance I'll be overlooking something.

The walls that surround the stairway are just drywall, but due to poor craftsmanship they aren't totally straight. As a result, some steps are 36.5" wide while others are 34.5". It's not just the drywall. The studs are the problem. The stringer itself is sound, but in some places the drywall overlaps it such that the stringer edge is actually inside the wall in some places. Not dramatically so, but as much as 3/4" in some places.

Anyway, I have the sawsall, but I think the current treads only have about 3 common nails on each side so I'm not anticipating too much problem. It would be much easier to rip them out, then install the drywall, then the new treads, but with the stringer sort of inside the wall I don't think that will be possible. I'll have to custom cut all the drywall to wrap around the treads.

I think I know what I need to do. Say, how long does it usually take for the ployurethane to stop smelling? I expect to put on 3-4 coats and do the whole thing inside and room temps. Will the odor be gone in a week?

 

Maybe. If thats a factor you might want to get a low VOC product, commonly available, which has no or low odor.

No idea what your stairs look like but you could also install a skirt against the wall to cover the drywall... new treads would butt up to the skirt.

 

I don't remember all the specifics but whatever you do for treads keep in mind the code requirements for tread depth, riser height, and overhang variances. An oil based polyurethane will take a while to dry and there will be an odor. Use a good flooring poly that will give good wear. Last N Last is excellent. You indicate that you want to do the install and then apply the poly, but reconsider applying the poly before you do the install.....that way you can do as many coats as you want, do the work in a basement so the house inhabitants won't have to smell poly for days, be able to walk on the stairs as soon as they are installed.
If I recall correctly the original treads are 1 1/2" thick If so take them off, install 3/4" ply as a subtread, then buy unfinished 3/4" treads....which will be less expensive than 1 1/2" treads. Just a thought.
Can't understand why the retreads warped....how thick were they? Did they seem to follow the contour of the treads you glues them to?
PL Premium Adhesive is well regarded and virtually odor free.

 

JIMMIEN,

I used Minwax ploy for floors. I still have half a gallon left so I'll probably just use that again.

Here's the retreads that warped:
https://www.lowes.com/pd/RetroTread-...-Tread/3191553

Here's the new full "tread" I plan to use:
Stairtek 1 in. x 11.5 in. x 36 in. Unfinished Solid Builder Grade Red Oak Tread-BTROC1136 - The Home Depot

Is it really necessary to put 3/4 ply UNDER each tread before install? I hadn't heard that before and I've got my shopping list already to head out tomorrow morning.

With or without the plywood, my plan is to use cove molding where the riser and tread meet if I can get the stain to look right. I'm still hoping I can reuse some of the old risers if I can get the old glue off.

 

If it was the low-voc variety, that's probably why it warped... too long of a dry time. The retread instructions specify a urethane, so I probably wouldn't even risk using the glue I mentioned earlier.

 

You don't need the plywood subtread....if you used a new 3/4" tread then 3/4" plywood under it would have given you the same step height as the original which I thought was 1 1/2". There are building code requirements for tread depth and riser height which include the first floor and second floor riser heights. If you're happy with the HD treads then go for it. The ones I had seen in HD were imported and the staves did not have a very good grain match. I found better treads at a local lumber yard for less $ than HD charged.
PL Premium Adhesive is a urethane product.
If you get a good tread to riser joint then you can go without the scotia/cove molding unless you want to. One reason to forgo the scotia/cove molding is if you decide to add a stair runner. Polyurethane stair treads can be slippery without the correct footwear.

 

JIMMIEM,

Thanks again for all the help and the fast responses. I liked the 1 1/2" thick original treads for their strength, but I don't need to match them as I'll probably be recreating all the risers again anyway. The only plus to adding the sub-tread ply besides strength would be I could rip everything out, install the ply, then have usable stairs while I work on the rest of the project. I actually have a lot of scrap 5/8" ply I could use instead of 3/4". I'm gonna get the treads today, check the fit and think about my options. Thanks for the idea whether I use it or not.

As mentioned, the Home Depot treads I'm looking at say 1", but I'm not sure if that's a true thickness. Guessing from memory I think they are the full 1", but what would be the minimum thickness I should use assuming I don't use the ply sub-tread?

 

One more thing... I've got a lot of risers I might be able to use if I can get the old glue off. I actually made my own risers out of a sheet of red oak ply so it's just a veneer. I've got sanders, including a belt sander, but the glue always gums it up so fast and ruins the paper. Maybe if I wait longer for glue to totally cure? Getting glue off the back doesn't matter because it won't be seen, but there are areas on the edges of the front where the lip of the retreads was glued to the riser. Those are the areas I'm concerned about. Then again, although more expensive, it might be easier just to buy another sheet and make them again from scratch. Hardest part was finding a decent board at HD that wasn't all scratch up.

 

If the original treads were 1 1/2" thick and you replaced them with 3/4" thick treads the riser height from the bottom landing to the first step would be decreased by 3/4" and the riser height from the top step to the top landing would be increased by 3/4".......these may make your stairs non-code compliant. Besides being code compliant it is also a safety issue. Use a tread thickness or a tread/subtread thickness that keeps you code/safety compliant.
How about an oscillating multi tool with a scraper blade to remove the glue.
Yes, sometimes finding good lumber and plywood at the big boxes is a challenge. Any local lumber yards near you? Their stuff is usually better than what the big boxes carry.

 

JIMMIEM,

It took a couple stores to find treads that weren't split or out of stock or marred up, but I've got them. Honestly, I find one of the worst parts of the job is getting the lumber. Sorting through all the bad pieces and trying to find someone to help you cut the board really takes up a lot of my time. I'm not as young as I used to be and I own an SUV, not a truck.

I get your point about the level of the steps. The bottom and top step were already off with respect to the other 9 steps so if they were already out of code for the last 20 years that I've owned the house. Still, I want them to look right.

So, for the boards that will go under the new treads, how important it is that I use only 1 sub-tread for board. Say I've got 10" x 36" tread. Could I use two 5" x 36" boards under the finished 1" thick tread or must I use a 10" x 36" "full" piece? I don't see why I couldn't use two sub-tread boards considering it's purpose.

Either way, I've got to get started as the weather's starting to turn. I've done my prep work and I'm ready to start cutting again. I sure have dragged this one out. lol.

 

You'll be fine with the two 5" pieces of sub-tread. Secure them well with construction adhesive and screws...make a note of where the sub-tread screws are so that you don't hit them with the finished tread screws/nails.
Also, you can leave a slight (1/8") gap between the sub-tread pieces just to avoid any potential squeak spots.
Keep us posted on your progress and post pictures if possible.

 

JIMMIEM,

Okay, thanks for the tips. This is gonna take a few days. I'll post back at the end. Thanks for all the help.

 

I know this is an old thread, but I just wanted to post back and show the results. Thanks for all the help I get here from the friendly people. Much appreciated and valued.

My stairs turned out well enough. Nothing fancy but a good result considering the problems I had. It was tricky getting the drywall to contour. As someone suggested, maybe I should have put the side rails on the steps to make the stairs-to-drywall transition cleaner, but this worked well enough for me this time around. For the stair backs, I just bought a sheet of 3/4 Oak plywood and cut it up. Seemed to match well enough for my tastes.

Thanks again!