Deck stair stringers - PT - warping
#1
06-09-17, 06:14 PM
Deck stair stringers - PT - warping
I cut some stringers for my deck about a month ago. They were all nearly identical when cut. I went to install them the end of this week and they've warped terribly. And, by terribly, I mean about 1/4" here and there, but very noticeable. I've tightened them up by using some 2x4 as I need these to support the Trex boards I'm using, but it still looks terrible to me.
My question is, should I start all over with some soaking wet, fresh boards that I can attach the treads to right away, or would I be just as good shimming the treads for each step?
I'm willing to start over, however if they are just going to bend and warp again with the treads attached, will it end up looking worse this way?
Any other tips or suggestions are welcomed.
Attached is the way they look now. The shots of the level are about the way 4-5 steps are.
My question is, should I start all over with some soaking wet, fresh boards that I can attach the treads to right away, or would I be just as good shimming the treads for each step?
I'm willing to start over, however if they are just going to bend and warp again with the treads attached, will it end up looking worse this way?
Any other tips or suggestions are welcomed.
Attached is the way they look now. The shots of the level are about the way 4-5 steps are.
#2
06-10-17, 02:56 AM
It's always best to cut and secure PT wood promptly, that way it's less likely to warp as it dries out. If the decking will 'bend' enough to be secured the way it is I'd be inclined to leave it. Otherwise you could shim the low areas .... or cut a new stringer 
#3
06-10-17, 05:57 AM
Group Moderator
In my experience, unless you cut each one and then stacked all 4 together and fine tuned them with a grinder and flap disk, AND then kept them in the same order left to right when you attach them, you will have some variation in them like what you are seeing.
But yes, they can and will warp, and there isn't much you can do about it. Composite decking has no strength to keep the framing straight, so even if you frame everything perfectly... and get it straight as an arrow then deck it, any joist could warp at any given time and make the deck look wavy. Decks start warping the minute you finish framing.
But in looking at the stairs, put your level on the pavers at the bottom landing. See if the pavers are level. And IMO pavers are after horrible choice for your landing as they will also move. Looks to me like the 2nd riser from the left could be swapped for the riser on the far left... or maybe the paver that the 2nd one from the left sits on is a little high. Hard to tell without being there.
If they arent attached for good, you could stack them together, line them up, and dress them up with a grinder and sanding flap disk. Then make sure the surface they sit on is perfectly level before installing them again.
But yes, they can and will warp, and there isn't much you can do about it. Composite decking has no strength to keep the framing straight, so even if you frame everything perfectly... and get it straight as an arrow then deck it, any joist could warp at any given time and make the deck look wavy. Decks start warping the minute you finish framing.
But in looking at the stairs, put your level on the pavers at the bottom landing. See if the pavers are level. And IMO pavers are after horrible choice for your landing as they will also move. Looks to me like the 2nd riser from the left could be swapped for the riser on the far left... or maybe the paver that the 2nd one from the left sits on is a little high. Hard to tell without being there.
If they arent attached for good, you could stack them together, line them up, and dress them up with a grinder and sanding flap disk. Then make sure the surface they sit on is perfectly level before installing them again.
#4
06-11-17, 10:51 AM
The pavers are completely level, I made sure of that before I even started with the stringers. I did end up taking them back down and stacking them to see where they were off. 2 were still nearly identical but the other 2 were off as much as 3/4" in some places. Unfortunately (maybe fortunately) I'm going to be forced to start over with a 3rd. I say fortunately though because I thing what I'm going to do is only have a 3rd in the middle, but use 2x8 treads rather than the several 2x4's I was going to use to brace the deck boards. I think this will probably be more stable in the long run.
