Repair cracked stair tread...

[blueman]

One of the 12" wide treads on our main staircase has an ~18" longitudinal crack in it. As per an earlier thread, the consensus seems to be that these treads are 150 yr old heart pine.

Here is a link to a pic: http://96.252.37.8:8080/public/1stFlrTread.jpg I am not concerned about the visual look of the crack (if anyting it adds "character") but the area under the crack is not well supported and gives a bit when you put weight on it -- in fact, the absence of such support may be the proximate cause of the crack. The crack has probably been there for many years.

Since replacing the tread is not easily feasible given the old wood, I would like to repair the tread.

Now removing the tread would not be easy since 2 balustrades are toenailed into the other side of the tread and removing the entire bannister and balustrades *seems* to me to be a big job.

So, I was thinking it might be easier for me to access the underside of the tread from the alcove underneath the stairway by cutting through the plaster and lathe on the underside of the stairway. My idea would be to expose enough area so that I could slip another board underneath the tread to span the crack and add support.

To secure the support, my thought was to cover it with glue (either polyurethane or epoxy). Assuming that I won't be able to get good clamping pressure from below, I would run some temporary small gauge screws through the face of the tread to temporarily clamp the tread and support board together. Alternatively, I could try to expose more of the stair underside at the risk of creating more mess and a bigger plaster repair job.

Before, I go cutting into the plaster and lathe, I wanted to get advice on whether this is a good approach along with any additional advice or pointers. Of course, I am open to *any* other better suggestions.

Thanks

[hrhofmann]

I would glue the repair plate to the bottom of the cracked tread as you suggested, and also secure it with screws just long enough to go into the cracked tread, but not so long as to come thru the tread, and leave the screws in permanently. If the tread crack is 18 - 20 inches long in a tread that is probably 30 - 44 inches wide, I would work in as big a piece of wood as possible and not skimp on the screws. You may want to predrill the holes in both the repair plate and the stair tread to prevent any further cracking/ I think regular wood glue should be ok, it dries so strong that a different part of the wood will crack before the glues section will crack.

[JIMMIE]

I see how they are toenailed in with finishing nails. I dont understand why unless there is nothing under them to nail to, thats a scary thought. I dont think the tread would really be that hard to take out. It looks the the front half of the tread would come on out with a little persuasion. Then you could glue it back together and nail it back down. Forgive me for saying so but this doesnt look like a quality job to start with. You would probably do well jsut to pull out the tread and replace it with another pine board.

Jimmie

[aemeijers]

How thick is the tread, and how steady are your hands? Or are you inventive enough to rig up a jig to drill in from the nose of the tread to within an inch of the crack, then drill a smaller pilot hole through that hole, and draw the crack shut with a long screw after packing it with epoxy? Once epoxy cures, fill the hole with a dowel. I'm thinking a long sharp spade bit for the big hole, and then the tiniest wire-fishing bit you can find for the pilot hole. (I've seen some real skinny ones for alarm system wires, used to go from a window up through a top plate....) Failing that, a piece of steel rod cut off with bolt cutters to make a point, would work for a single hole.

Last time this sort of thing was discussed on here, several people suggested cutting the riser below the split tread, and gaining access to the bottom of the tread that way. If riser rides in a notch at top or bottom, you will have to cut, like with a multimaster or clone, leaving as small a slit as you can. If the riser isn't trapped, temporarily screw a cleat to the front to have something to pull on, and drill out the nails, or drive them through the riser with a nail set. Hard to say without seeing it up close- a lot depends on if the riser is trapped in the skirting (probably the wrong term) on the sides.

Let us know how it comes out, and how you did it. I'm curious at this point.

-- aem sends...

[blueman]

I was assuming that I would not have enough access room to screw in the screws from below so that instead I would need to secure the backer board by driving screws through the face of the tread from above. In order to preserve the cosmetics of the tread, I was hoping that once the glue set, I could remove the screws and at most have to add a wee bit of woodfill to the holes left after removing the screws. My thinking was that even if the underside of the tread is not completely smooth or flat that epoxy or maybe construction adhesive would hold the boards together securely after fully curing.

I was assuming that the underside of the tread may be rough so that a more space-filling glue like epoxy or construction adhesive might be better.

[blueman]

Maybe I'm making it too complicated but it seems to me that to remove the tread, I need to remove the 2 balustrades that are toenailed into the other end. But then to remove the balustrades, I would need to remove the bannister. But then to remove the bannister, I would probably need to disconnect all the other balustrades from the other treads since they are nailed into the bannister... this seems like a lot of work and a lot of risk of splitting the balustrades or otherwise affecting the finish and/or integrity of this old railing system.

I guess I could try to get a blade underneath to cut the nails... but I worry that between doing that and then trying to remove the tread that I run the risk of splitting the wood or messing up the finish which would require more work to repair... So, I thought it might be easier to go through the underside which hopefully just requires cutting through and patching plaster..

It's not the quality so much as the fact that the stairs are 150 years old and I doubt I could match the wood that easily - the imperfections are probably more the patina of age and use across a century and a half rather than a comment on the initial quality of the install -- heck, how many stairways installed in new houses today will be around in 150 years... In any case, it's like antiques where refinishing or replacing with new parts can often decrease the value even though it looks "nicer."

Also, there is no "front half" of the tread -- it's one 12" tread that is split along half of its length.

[blueman]

Wow -- that sounds hard (at least for my skill level) -- the tread is about 3/4" thick and I would need to drill a hole 6" long just to get to the crack. Also the crack itself appears quite old and even with a screw drawing it together, I'm not sure I would get good, clean wood-on-wood adhesion. Given that most of the force is due to weight bearing differently on the 2 sides of the crack, I would worry that such a repair wouldn't hold -- or worse that it would cause the wood to split open around the screws since there would be only around 1/4" of wood above the screw. Finally, the hole filled with a dowel might still stand out...

I can see that as an approach. But wouldn't it be easier for me to access it from the underside where I would only be opening up plaster which is much easier (at least for me) to patch cosmetically than having to cut a riser.

Will definitly do that!!! Thanks again for your input!!!!

[JIMMIE]

Sorry but it looks like you can see a lot of finishing nails in the wood already, maybe Im mistaken but it didnt look like 150 year old carpentry to me. I meant glue the front half as a result of the split.

Jimmie.

[HeyBub]

If you can get underneath to afix the sister tread, you can put screws in place. Screws alone are perhaps 30% effective. Glue alone is perhaps 30% effective. The two together are better than the sum of the parts. You can't use too much glue nor too many screws.

As long as you're under there, consider reinforcing as many other steps as you can reach. Someday some 300# fellow is going to walk up these stairs carrying a 150# flat-screen TV...

[Jay-T]

I have a hunch that when you open it up from underneath you will be able to see what your options are in terms of fixing the crack and supporting the tread. For example, you may find that you can add a supporting strip on one end and screw that into the stringer on the side.

You mentioned that there is wood lath and plaster. I assume that the wood laths will run across, from stringer to stringer, parallel to the tread. So, you should be able to cut out a whole section all the way across, and that should be easier to patch in one piece with sheetrock rather than trying to cut a small hole and patch that. I usually use a handheld sheetrock saw to cut the plaster along a line in between two pieces of lath. Then I knock out the plaster in the section of plaster that I cut out and then take out the underlying laths that go all the way across. That avoids cross-cutting any of the laths which helps prevent vibrating the laths and causing unwanted plaster to come loose around the outside of the hole/opening that is being cut out.

I have also used Gorilla glue from underneath to glue and seal cracks and the joints where the treads meet the stringers and risers, etc. I like it because it expands and fills the area and seems to stay just slightly flexible rather than brittle like regular wood glue.

[Jim Elbrecht]

epoxy it.

Clean well. Use wood *epoxy*, not fiberglass. Mix it thick so you need to force it into the crack.

If you can get underneath, all the better. Put some tape over the crack so you don't lose your epoxy. Otherwise plan on doing it in 2-3 layers.

Epoxy will flex with the tread & will be stronger than the wood. A piece underneath is just asking for more trouble down the road.

IMO- if you add a piece underneath - don't glue or screw it. It will not expand and contract at the same rate as the tread, so you'll likely end up with a larger crack, or a warped board. . . or it will just tear the glue joint apart.

Just install it as if it was a shelf with the tread sitting on top of it. Screw cleats into the stringers and riser. I'd only fasten to the stringer treads.

Without glue you might end up with a squeaky tread. That's not necessarily a bad thing.

Jim

[amdx]

I see there is a wall on the left side, would it be any easier to open the wall then to open the alcove underneath the stairway ? Mike

[willshak]

blueman wrote the following:

Like you surmised and others have agreed, you need to get to the bottom of the tread. All you really have to do is to supply a support for the tread. If you can get to it, a piece of one by ? nailed or screwed to the stair side under the cracked side should be sufficient. You don't have to nail or screw the support close to the tread bottom. Use a wide piece of one by ?, i.e. 1 x 4, or 1 by 6 so that you can have more room to nail or screw the piece to the side. It is not necessary to put screws into the tread. The tread isn't going to move in any direction except down.

[blueman]

No need to apologize -- I'm the one who should be thanking you for the input!!! Usenet for me is all about getting multiple inputs and trying to learn a bit from everybody to come to the best sum total solution. Unless someone is intentionally being a troll or jerk, I can probably learn something from every post.

In any case, any finishing nails were probably added over the years for who knows what reasons... but I'm 99% sure that the stairs are original to the house and that part of the house was built in 1860...

[blueman]

Excellent (but scarey to think about) suggestion. On the other hand since the understand of the stairway has a "curved" contour, I probably will try not to rip out any more plaster than I absolutely have to which means I at most will likely have access to the step above and below the one in question...

[blueman]

Very interesting and clever thought, but wouldn't the stringer be in the way? And to get around it, that would probably require me to pull out an even bigger section of the wall on the other side.

Also, the other side is our living room while the underside of the stairs is in the front hall but rarely if ever seen -- also the plaster on the underside of the stairs is hand contoured to follow the (uneven) rise and twist of the stairs -- so that any imperfections in my patch job will likely be less noticeable than they would be on the "smooth" wall of the living room.

[blueman]

Excellent idea. Maybe I will just sister a couple of 2xX pieces onto the stringers adjacent to the crack -- this should certainly provide a lot of vertical support which as you correctly surmise is the only real direction of force.

Alternatively, I could place a board underneath the tread but rather than gluing/screwing it to the tread, I could rest it on cleats attached to the stringers (I think this is similar to another poster's) suggestion.

In any case, I imagine the exact flavor of my solution will depend on what I find when I expose the underside of the stair. But I didn't want to make a mess until I received some reassurance that I was at least heading in the right direction... I will keep the group posted on what I find and what amalgam of solutions I end up implementing.

Thanks, Jeff

[blueman]

Very wise advice...

Thanks for the suggestions -- patching will probably be a little more difficult than just sheetrock since the bottom of the stairs are contoured rather than flat -- so probably I will need a combination of sheetrock base and plaster/setting-joint compound fill.

Personally, I have been using more high quality (West Systems) wood epoxy and less Gorilla glue since in my experience, I have found that:

- Polyurethane glue makes a mess with all the foaming which requires careful cleanup/scraping

- My understanding is that the filling portion of polyurethane glue is mostly dried "foam" that is not nearly as strong as epoxy which when used with the right filler can be a super-strong structural filler

- Finally, clamping is less critical with epoxy since you don't have to counteract the expansive force of polyurethan.

[blueman]

I have been debating between cleaning it out and between leaving it as-is as a mark of "character" -- my concern is that if I clean it all out and can't bring the two sides back together tightly, then the epoxy fill may look less authentic and more like a hack than just leaving the crack alone...

Definitely - I have become a real fan of the West System... it is so much better and more versatile than the store bought stuff in the syringes and tubes.

I like that idea -- assuming I can get good access which I won't know until I get under there...

I could always put a layer of Resin paper between the tread and the support which would be analogous to the way Resin paper has been traditionally used between the underlayment and the overlying T&T strips.

[Tony]

Without a doubt fixing it from the bottom is your best bet. And yes the reason it cracked is most likely because it had no support, which I hope is just this tread and not all of them! Like others said, glue and screw a piece of wood under it. And while down there attach something to the side that will give it support.

My first idea was to drill a long hole and put in a couple long screws, but with no support below, you are just asking for more trouble. If you want to push instead of pull the crack together until the glue dries, you just measure from the front of the split tread to the wall at the bottom of the steps and make a T with a 2x4 with the short end on the wall and the long end pushing on the stair tread. First I'd try to get the little specks of paint an whatnot out of the crack. Add shims to make it fit tight. Do this before the glue and screw underneath.

Although the more I look at the photo, the more it looks like the tread doesn't go into the sides. It looks like only some plaster/spackling and finishing nails hold it down. I'd try removing plaster from under a lower tread to see how far the tread goes into the sides of the stringer, if at all. If it comes out that way it would save having the hole in the plaster down below.