Fixing and caulking rotting joints on exterior wood stairs

[jaxs]

Filling voids left by rot might slow rot in that area but not by much and will not add strength. I would install a ledger beneath each tread replaced.

As far as treated lumber,there's more than one level of quality and it seem's big box usually stock's the low grade. Wolmanized is a patented process that has stood up well for me. I installed Wolmanized boards in the floor of a trailer more than 20 years ago and it's still solid. Boards in my 9 year old deck show no rot and have little warp. It's possible the extra step I take when using treated boards helped (I hope so). If a board must be cut to length,I try and stand cut end in deck treat a few hours.

 

[WVBill]

Pull off the all the treads and use Simpson TA9Z of TA10Z Staircase Angles as brackets for hanging new treads. Cut the treads just slightly short so there is a gap between tread and stringer so no water is trapped. You could rip 1/4" off the risers and hang them with Staircase brackets so there's a gap at the bottom too.
Start at the bottom and work up one or two stairs at a time to have a working platform.

https://www.fastenersplus.com/SSP A...9Z.01.jpg?resizeid=19&resizeh=400&resizew=400

 

[CADplans]

I would take an opposite approach,,
rather than "filling" the joint,, I would drill a couple holes so that water could drain away.

I had a similar issue on a flat deck,
where the boards touched, the boards started to decay.

I took a circular saw, and opened the joints, so the water could drain.

The wood can not rot if it is dry.

The "Bondo" solution, on the other hand, will trap water permanently in the joint, promoting rot,,,

 

[GLyford]

Is that a stringer or just an endcap? It it's a stringer, then WVBill probably has the right idea. If it's an endcap, I think I would pry it off/unscrew it and figure out a way to reattach it with a gap somewhere between 1/4 and 1/2". Like maybe get a box of oversized galvanized hex nuts (3/8, maybe?) and as every screw you use comes through the board, slip a nut on it before running it the rest of the way into the end of the treads/risers. If you are worried about compressing the wood, then maybe washer-nut-washer. Note that I am talking about just hanging them on a deck screw as a cheap loose fitting spacer, not actually getting ones the correct size/thread to actually thread onto a fastener. This also assumes there is still any end grain wood left not rotten enough to hold deck screws.

 

[/pine]

The board in question appears to just be a skirt board...the actual stringers are likely cut out and hidden...the reason for the rot has already been pointed out...

 

[Budweiser John]

Depending on the tread span I would replace all the treads and risers with ‘Trex’ or ‘Azek’.
Either of these materials will solve your problems in perputity. However, they’re hard on the bank account.
Today’s treated lumber is pure crap.
Anyone got a fiver of Creosote your willing to part with?

B. John

 

[Steppenwolfe]

Thanks for the help guys.

I haven't yet pulled off a tread or riser to see how bad it looks underneath on the stringers. With any luck, it won't be too bad and I can soak some liquid wood hardener into the rotten spots and/or bondo anywhere I have to dig out rot.




If nothing else, I would make sure there is a gap there, so the risers and treads aren't in contact with the side boards. In retrospect, this style of stair, with side boards boxing things in, seems like a bad idea. Building it tight with no gaps (which would otherwise be a good thing in carpentry) makes it worse. If I had to do it over again, I'd skip the side boards, have the treads overhang, and just plan on sistering multiple stringers to get the needed stiffness.

Yes, that would help. Are you using .25 or .40 treated lumber?

 

[s219]

Yes, that would help. Are you using .25 or .40 treated lumber?

I'll have to see if I can find a tag to know what the treatment level was, but it was basic off-the-shelf 2-by lumber from Lowes. It ain't doing great!

For those asking, there are regular stringers hidden out of sight, sistered to the inside of the outer 2x12 board. In retrospect, I don't think this is a good design for dealing with moisture, although I have used the same design on three other sets of stairs on my property that have zero issues. And the rot is just on about 10 steps out of the 45 going down to the pier. So I either think those steps get wetter and get less light/air, or it's just crappy treated lumber.

Thanks for all the responses so far guys, it helps! I plan to pull off a couple treads/risers this weekend and see how bad it looks underneath.

 

[Tractor Seabee]

In the time it would take to do all the repairs to something already damaged; I could build a new set of stairs using all the lessons learned from the rotting ones. Urethane sealant works good on new wood to prevent water intrusion into the joints. Its actually a fairly good adhesive also.

Ron

 

[quicksandfarmer]

I'm surprised that no one has mentioned that the manufacturers of treated wood typically recommend that cut edges be treated.