Questions and opinions of my staircase project

[Mike J Lewis]

I am working on a stair case project (my home) and have read several great threads on SC covering the subject; however, this is a big project (for me) and I want to make sure it comes out really good. I am weighing three options for the tread-riser-stringer attachments (listed below) and I would really appreciate the comments, suggestions, and even criticisms of some more seasoned or experienced contributors to this forum on the pros/cons of each.
This is a simple staircase of eleven 36” steps that go straight down from a 2nd floor landing to the 1st floor landing. It is boxed & skirted entirely on one side, most of the way down on the other, with the bottom 3 steps exposed on one end and a short handrail to the newel, supported by double pin-top balusters on each step. I am removing carpet and replacing the old treads/risers, but keeping the general design of the staircase as-is. The existing(three) pine 2x12 stringers are in good shape and true to +/- 1/16th inch in all directions. I am planning on installing 1” bullnosed oak treads and ¾”poplar(?) painted risers directly to the stringers.
I can keep all traffic off the stairs for a few days as needed, but I’m not comfortable with attaching the treads with glue only. Even after reading the thread regarding the pros & cons and I can’t really validate that opinion, but if I err, I want it to be on the side of ‘too secure’.
Here are the options for attaching the treads that I’m weighing out and some questions that I have not found answers for yet:

Option #1:
· Leave treads unfinished
o Glue all wood-wood contact surfaces (except ends) with PL.
o Fasten down with six #7 x 2-1/4” SS trim screws.
o Wood putty pre-drilled holes to fill.
o Sand, stain and 3x coat with polyurethane in place.

Option #2:
· Cut, sand, and finish top and edge of treads prior to installation.
o Same glue strategy.
o Fasten down with six 15 ga. finish nails. Fill holes with putty colored to match stain.

Option #3:
· Same as option #2, except instead of nails, pockethole and screw through the stringers from underneath (will have to rm/rp sheetrock, no big deal) with six 1-1/2” washer head screws, penetrating ¾” into the oak tread.

Other general thoughts and questions:
· I plan to measure each and back cut the risersfor better fit.
· Should I kerf the underside of the treads (3 cuts, 1/3 the thickness) to prevent cupping?
· Should I attach the tread first and then the riser above it, or attach the upper riser first and then butt the tread up to it? I’ve seen installations both ways, but which is best?
· If the latter, should I rabbet the lower front edge of the riser to accept the tread, or simply back cut the tread to fit?
· Should I dado the underside of the tread to accept the riser?
· Has anyone tried dovetailing the riser to the underside of the tread for additional soundness? Any concerns about weakening the bullnose in that situation?

Lacking 1st hand experience in stair work, any input provided is greatly appreciated!
Mike

[Mark Bolton]

If your willing to remove the Sheetrock that's the answer. Then you can pocket hole everything together and even screw your risers to your treads and pocket hole them to the tread above. Blind fasteners are always the best if you can.

[Mike J Lewis]

Thanks Mark. Replacing the sheetrock is not a big issue, just making sure I was securing the tread firmly. My initial thought was that trim screws through the tread would be the most secure, but PH screws from the underside would be secure enough (in addition to adhesive)? I've never used a PH screw in a place that would get a lot of load and movement, so no experience to fall back on.

[Dave Zellers]

Other general thoughts and questions:
· Should I kerf the underside of the treads (3 cuts, 1/3 the thickness) to prevent cupping?
No
· Should I attach the tread first and then the riser above it, or attach the upper riser first and then butt the tread up to it? I’ve seen installations both ways, but which is best?
Risers first, then treads. You only need to nail the top of the riser (nail hole hidden by the scotia) since you are screwing the bottom to the tread.
· If the latter, should I rabbet the lower front edge of the riser to accept the tread, or simply back cut the tread to fit?
1/4" rabbet, screw from behind
· Should I dado the underside of the tread to accept the riser?
Only if you are not going to apply scotia under the nose. If you rabbet the back of the tread and dado for the riser in the front, you will have to allow for variations in the stringers. If you only do a rabbet/dado at the tread back, you can let the screws sock that joint tight and let the front rest where it will since you said that variance is at most 1/16". The scotia will cover glue ooze. Then you have to decide between pocket screws and nails. I have always face nailed into the riser and stringer with 8d finish nails by hand and filled them. PL or equivalent underneath. My stairs are as tight and quiet as the day I did them 25 years ago. It's important to note that the tread does not need to make full contact with the stringer. Construction adhesives are made to fill gaps.*

* with this in mind, you can actually do the dado under the nose too (1/8" deep) and pre cut all your risers and treads since you have said the stringers were cut accurately. Cut the dado maybe 1/32 wider than it needs to be and let the PL ooze out and fill that space.

[Mike J Lewis]

Many thanks, Dave. I'm going to have to read this through a couple of times, but it's just the kind of info I'm looking for. Much appreciated. Mike

[Sam Murdoch]

Here is a thread in which I (and others) posted quite a few thoughts on your subject. No need to repeat it all - here is the link - http://www.sawmillcreek.org/showthread.php?204893-Stair-project-installing-hard-wood-treads

Adding a bit and notwithstanding what I wrote in the earlier thread - with your preferences in mind I would opt for your Option # 1.
A word about trim head screws.The very best in my opinion are the GRKs with the gold finish. The heads on these (as well as the threads) just don't strip out in normal heavy use. I have in the past used Stainless screws thinking that nothing could be more rugged but only to find that not all stainless is created equal these days. There are a lot of junk SS screws out there. Buyer beware. Use GRKs is my strong recommendation.

[Dave Zellers]

· If the latter, should I rabbet the lower front edge of the riser to accept the tread, or simply back cut the tread to fit?
1/4" rabbet, screw from behind
To be clearer- you rabbet the back of the tread and dado the bottom of the riser.

[Dave Zellers]

Here is a drawing.

269351

[Sam Murdoch]

Dave's drawing is good info. The only thing that I would do differently is use Titebond II type glue at the tread and riser joints and the PL only on the surfaces that will contact the stringer. Only reason being the viscosity difference. A good joint could be kept apart by the thickness of the PL whereas the yellow glue will spread easily on the well fitted wood joint and clean up easily too, but most importantly will not at all be a compromise to the integrity of the joint.

[Dave Zellers]

Yep- good points.

[Tom Hammond]

I also put a dado on the underside of the tread for the riser to fit into. I usually make them with a dado set in the table saw 1/8" deep and about 1/16" wider than the riser thickness, with the additional width toward the back of the tread. If you're looking to have a 3/4" overhang, put your fence 3/4" from the dado set and rip the dados. In the diagram above, though, the dado at the base of the riser and the rabbeted tread is, I think, overkill. I also don't use cove mold under the nose (use of it kind of defeats the point of the dado, which is not alignment, but is to hide the joint facing front. Whenever possible, I find alternatives to nailing through the faces of the treads and risers.

[Pat Barry]

With regard to option 1, have you considered using bungs to backfill the screws rather than wood putty? Seems this would make for a much cleaner look.

[Mike J Lewis]

Thanks, Sam. I read the thread you referenced from 06-2013 and glue/nails/both thread from 02-2010 that was linked in it, but in both situations, it sounded like they were using an old tread or a sub-tread and had chosen to attach to it rather than directly to the stringer. My only option at this point is to go directly to the stringer, and if I attach from underneath (which I like for aesthetics) I'll have to go with the pocket-hole screw. I haven't had enough experience with PH screws to know if they will hold up in this load-bearing and shifting situation as well as face-nailing or screwing. And I had no idea that some SS screws might not stand up to the task. The ones I bought at the big-box store are Grip Rite, so if I pursue that option, I'll take the time to locate GRK screws and use them. Thanks for that tip.

[Mike J Lewis]

A picture is worth a thousand posts, Dave. That's pretty much what I was thinking, except that I was going to dado the bottom of the riser to the same width as the tread thickness. However, what you suggest looks like it would definitely add some strength.

[Mike J Lewis]

I've gotten a number of really good replies to my original post. I'm leaning strongly toward face-nailing or top down screws through the treads, as it seems like that method has the most support among the experienced folks. I would like to know if anyone has tried pocket-hole screws in this type of application and if so, did they hold up well? In a glue-and-screw joint, I've always assumed that the screw provided stability until the glue set up, but then the adhesive provided the real long-term holding power. If that's a correct assumption, PH screws and PL adhesive (with Titebond in the snug joints) might be plenty to hold this project forever, but I'm just a little leery of only having 3/4" of threaded fastener in the 1" tread. Not a gamble I'm likely to take unless someone has tried it and can say that it works well. When in doubt, go with the tried and true, right?!?!?

[Mike J Lewis]

You're probably right Pat, especially after I stained some test swatches yesterday with some putty-filled holes in them. Didn't like the way the hole looked afterwards- plugs would almost certainly be a better choice.

[Ethan Melad]

For what it's worth, I went fastener-free with the stairs in my house. Liquid nails only, directly to stringers, no issues so far. This was the first and only time i've done stairs so I cant say i have much experience, but so far so good. i didn't have access to the undersides as drywall was already up, and i wanted a clean look with no exposed (or filled) fasteners.

[Sam Murdoch]

Thanks, Sam. I read the thread you referenced from 06-2013 and glue/nails/both thread from 02-2010 that was linked in it, but in both situations, it sounded like they were using an old tread or a sub-tread and had chosen to attach to it rather than directly to the stringer. My only option at this point is to go directly to the stringer, and if I attach from underneath (which I like for aesthetics) I'll have to go with the pocket-hole screw. I haven't had enough experience with PH screws to know if they will hold up in this load-bearing and shifting situation as well as face-nailing or screwing. And I had no idea that some SS screws might not stand up to the task. The ones I bought at the big-box store are Grip Rite, so if I pursue that option, I'll take the time to locate GRK screws and use them. Thanks for that tip.

Worth another read Mike as at least by the 2nd page the OP was not attaching to existing plywood treads - in fact it was his original plan to attach ply to the stringers and we disabused him of that idea. Also some discussion of how to fill screw holes and the merits of glue only vs glue and fastenings and other options for attaching the new treads/risers to the existing stringers.

The problem that I have with attaching to the existing stringers with pocket screws is that 2x stringers are cut in such a way as to leave triangle pieces of short grain wood that will likely split or crack or at least be severely weakened by toenailing screws through their sides. They might not break initially but will certainly break in time as the stair case is used. So in the thread I refer to above I discuss adding nailers to the sides. Lots of work but will lead to a much more secure structure. With the joinery as Dave illustrated I truly am confident that you can eliminate lots of fastenings.

BUT, if you prefer to use screws I reiterate that your best option (IMHO) is # 1. There is a product called "Color Putty" that is a soft colored putty that is applied after the first coat of oil sealer then can be covered with more finish. This comes in a wide variety of colors and can be used with virtually invisible results. Also, as I explained in the first thread you can get good results with "wax" sticks like this product or other similar products - http://www.mohawk-finishing.com/catalog_browse.asp?ictNbr=109 No need to use countersinks and bungs. This treatment also can be practically invisible when done properly and you can blend colors to get a perfect match from one tread to the next.

Anyway lots of ways to do this and you certainly have enough info that whatever approach you decide will serve you well. Have fun with it .

[Marvin Wilson]

While there are 1000 ways to skin a cat there is only one best way and in this case it's using housed stringers. I did finish carpentry for 35 years and have seen many different techniques and have to say this is the strongest, most attractive and professional looking way to go. I can't come over and show you myself but here's a link to some utube videos that explain the process in detail. http://www.youtube.com/watch?v=xrFdO-y1YVM
Don't be intimated this is really a simple method with way less parts and steps than those discussed here. The video will show you how to determine the layout, make the jig and assemble the pieces. The result is a staircase that looks like a piece of furniture, no putty, no nail hole, no joke. Check it out.

[Jim Matthews]

With regard to option 1, have you considered using bungs to backfill the screws rather than wood putty? Seems this would make for a much cleaner look.

That's the way I was taught, and it was used on both my stairways.
It's not perfect; but none have popped out, shrunk or discolored.

[Richard Wolf]

You have gotten a lot of good advice. I would just like to add that I have no problem face screwing the treads down if you feel that will make you sleep better at night. The best investment you can get, is a 3/8" plug cutter. Most screws will fit in a 3/8" counter bore and you can make your own face grain plugs. If you are anal enough, you can match the grain almost perfectly and the plug will be invisible from eye level. Also, locate the screws in an organized pattern so if they are visible they are at least symmetrical. You never really want to use wood putty, it always stands out.

[Mike J Lewis]

I appreciate the time you've taken to share your expertise on this subject, Sam. I reread the linked articles and couldn't find the reference to adding a nailer to attach from underneath, but I'm pretty sure I understand what you meant. However, I just can't get my confidence level up on ph screws, so I'm really leaning toward a face nail or screw, although I'm still open to hearing from those who have used ph screws with success. I'm sure the (GRK) screw top-down through the tread is probably the strongest fastener, but a good solid finish nail seems to be a very common and accepted practice as well. I'm not under a deadline to complete this project (very patient spouse!), so I think I'll do some experimenting with fillers including Color Putty to see what gives me the most desirable end result and make a final decision on fastener methods from that. Using the joinery illustrated by Dave (very similar to that found in the G-W chapter that you posted) I think any of the fastenings discussed will give me adequate strength for a long-term, rock solid stairway. Obviously, this project is stretching the limits of my skill set, but I'm armed with a lot more information now and I think I can move forward with getting it done. Thanks again for your help. Mike

[Mike J Lewis]

Thanks Richard. You are right, I have gotten some excellent guidance and my stair project is definitely going to look and perform better because of it. Some of the comments just confirm and give me confidence in what I was already doing, but as we got into the detail more, I realized that the decision was more about how to backfill any holes, less about the fastener type to use. I'm going to practice a few different methods first to see which one I can do that gives me the best results for this project and decide on the fastening method from there. I think that any of the options should give me a good result, especially if I add some joinery at the riser/tread connections. Thanks for your time. Mike

[Marvin Wilson]

I read your question over and if you are going to put treads and risers on existing stringers would like to make a suggestion. To avoid cupping you should use a laminated (plywood) tread with an applied nosing and as Pat Barry suggested go with the plugs instead of filler. The plywood treads are available at most home centers and are the same thickness as traditional ones. They will not cup and eliminate the seasonal expansion and contraction that can split nailed or screwed treads or breaking the glue bond resulting in squeaky treads. The plugs can add aesthetic appeal to the job.

[Mike J Lewis]

I know you said not to be intimidated... besides, my stringers are already in place. It does look like a great method, but I think it's going to have to be a part of my NEXT stair project.:)

[Mike J Lewis]

Unfortunately, I already bought my treads. However, I am definitely giving the plugs a try. Thanks for the suggestion.Mike