I just installed some pressure treated 2×12’s as stair treads leading into a home. I few days later and I have noticed that two of them are lifting (aka; warping) in the front right corner. I thought pressure treated would was good for outdoors.
Any thoughts or suggestions as to what I can use for the treads?
Thanks, Dennis
Replies
Pressure treated wood, installed properly, should work just fine.
How was it fastened? How are the growth rings oriented? Was it wet or dry upon installation? What kind of fasteners did you use?
There are things to know about the characteristics of wood... just like any other profession requires bits of specific knowledge.
I assume you don't build for a living.
http://www.petedraganic.com/
You should stick to JLC where that level of condescension is par for the course.
The treads had been attached by using PLPremium and Simpson Strong LS50 attached to the stringers.
I wouldn't recommend using either.
The PL would likely fail due to the treating of the wood coupled with the absorption and disipation of moisture in an outdoor setting..
Furthermore, the Simpson LS50s could also be problematic with their outdoor life and the fact that the newer treated lumber is corrosive to all metals except stainless steel. Besides, I don't think that the LS50 would be deep enough to properly fasten the tread completely... not to mention that it wouldn't fasten it as securely as other simpler methods.
You could resintall new treads, no PL, no Simpson hangers. Use a heavy gauge stainless screw or properly treated steel screw through the side of the stringer (assuming you have un-notched outside stringers). Drive a screw every 2-3 inches begining within an inch of each end of the tread depth. Be sure that the screw depth is adequate. I'd suggest using at least a 3" screw. If you can find 4" screws... that would be even better.
http://www.petedraganic.com/
Simpson Strong LS50 attached to the stringers.
Simpson makes a product that is much better suited than the LS50s for what you're trying to do. "TAZ staircase angles" are a much heavier gauge and designed to support treads.
With that said, I agree with what Pete's concerns about the new PT lumber and metals. Even if you can get the staircase angles in a finish that's supposed to resist ACQ-induced corrosion, I'd personally be hesitant to rely on metal stair supports for that reason.
Edited 8/7/2007 3:17 am ET by Ragnar17
Dennis,
Generally speaking, I think that PT lumber is not exactly a high quality material. It typically has wide growth rings, is flat grained, and many pieces seem to be cut from near the center of the tree. All this results in a piece of wood that is not dimensionally stable.
We'd all be better off using clear, VG stock, but who can afford it?
The common alternative is to use two 2x6s or three 2x4s. They have less tendency to cup and/or twist.
If you want to stick with the 2x12s, maybe you could try kerfing the underside to try to relieve some of the internal stresses.
You make a good point that I failed to touch upon. I typically use 5/4X6 boards over stringers for my stair treads. Wider and heavier dimensioned boards are more susceptable to distortion although if properly fastened, they can resist it quite well too.
http://www.petedraganic.com/
Wide solid bords like 2x12 is never a good choice for treads in an exterior location. It will puddle water, soak it up or let it freeze, and react to the water and conversly to the drying action of the sun beating on it. The fact that it is large, flat, and exposed means it will continue to move. If I were required to use PT 2x12 for some design reason is such a location, I would dry it well first, then paint it three coats on both sides before installing it
The purpose of PT lumber is that it is treated against rot and other destruction by micro-organisms. It is generally a poor choice for exposed trim situations, but better for framing.
The new ACQ PT is now well known to destroy steel fasteners in the pressence of water due to reaction with the copper salts in the wood, so stainless steel is advised.
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
The new ACQ PT is now well known to destroy steel fasteners in the pressence of water due to reaction with the copper salts in the wood, so stainless steel is advised.
Piffin,
I've asked other people about this too, but what's your opinion on the stainless hardware? That is, how long do you think it will last with the ACQ? Any predictions?
No.Most of what I learn is from reading places like this, and from tearing apart old stuff ad analysing what worked and what didn't.This is too new.I have gone to trying to design my decks so that gravity is holding it together instead of teariung it apart. IOW, joists run across tops of beams...
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Use two 2x6s instead of one 2x12.