When can I stain new 'pressure treated' wood

[Rick Herrick]

I had to redo a lot of my decking 4 years ago.  All of the 2x4 and 2x6 material at big box stores said they weren't for ground contact.  4 years later I got these huge bugs (not carpenter bees) making tunnels through this stuff.  I had shoulder surgery and some other issues and I never got around to sealing them in any way.

I need to replace a few pieces but I don't want to leave them out in the sun for > 30 days before staining them.  If I give them a good sanding, can I stain immediately, assuming they aren't soaking wet when I buy them ?

 

[Sparktrician]

You might do well to pull up a few boards and verify that the substructure is still in good shape before spending a lot of time sanding and staining.  If you do have problems, rip it out and replace it with materials that ARE certified for ground contact.  Those materials are likely going to be soaking wet, so wait 90 days or so before staining them, just to let the excess water get out of the lumber.

 

[Rick Herrick]

Thats the point.  If I put up new boards and they are not stained, then I run the risk of these critters getting back in.  If I just lay them out in the sun, they will be warped beyond use in a week.

 

[Cheese]

Could you substitute redwood, cedar or cypress so that you don't have to wait for the fir to dry out?

 

[DavidCBaker]

I had to redo a lot of my decking 4 years ago.  All of the 2x4 and 2x6 material at big box stores said they weren't for ground contact.  4 years later I got these huge bugs (not carpenter bees) making tunnels through this stuff.  I had shoulder surgery and some other issues and I never got around to sealing them in any way.

I need to replace a few pieces but I don't want to leave them out in the sun for > 30 days before staining them.  If I give them a good sanding, can I stain immediately, assuming they aren't soaking wet when I buy them ?

I've been told by two different contractors that you have to wait a year, but I don't know if that's true.

 

[Holzhacker]

All depends on how wet it is when you buy it and what the weather is. Around here given the wood and weather usually 30-60 days.
The companies who pressure was decks, porches fences and then stain usually pressure wash 1 week, then come back in a week or two for the staining.
Buy a cheap wood moisture meter and check moisture level until dry enough. Paint and stain products often have a listing for maximum moisture content for use.

 

[Vtshopdog]

I did a bit of a deep research dive rebuilding a portion of my deck last year.  Ground contact lumber was very hard to find during COVID.  I dried mine by stacking with spacers between pieces and ran a fan continuously over the stack for better part of a week.  I compressed the stack with ratchet straps to keep boards from turning into pretzels.

Sanding the stuff is likely a bad idea as the injected chemicals are there to kill bugs and such and will be bad for humans too.  Also learned the newer treatments accelerate corrosion and special fasteners and hangers are recommended.  There’s a thread posted on the FOG with my rebuild.

Some general information from pressure treated lumber association here:
https://awpa.com/info/technical/homeowners

 

[Rick Herrick]

Could you substitute redwood, cedar or cypress so that you don't have to wait for the fir to dry out?

Got a quote from my ply/hardwood supplier.  He can get 16' lengths of 2x6 Western Red Cedar for $75 a pop.  He said its not cheaper to get smaller lengths, same price per bd ft no matter what.  After thinking about it, that really doesn't seem like a bad price.  Now I just have to figure out how to get it home.

 

[Cheese]

Got a quote from my ply/hardwood supplier.  He can get 16' lengths of 2x6 Western Red Cedar for $75 a pop.  He said its not cheaper to get smaller lengths, same price per bd ft no matter what.  After thinking about it, that really doesn't seem like a bad price.  Now I just have to figure out how to get it home.

Rick that's really the best solution...waiting for that treated to dry will take a lifetime...mine and then yours, besides when it dries it pretzels, and that's not pretty, a lot of that stuff becomes scrap.  Consider cutting those 16' lengths down to shorter lengths with a cordless saw. There's really no reason to haul 16' lengths home only to cut them down to the proper length.

Do you actually need 2x material when 5/4 material is usually what they use for decking?

 

[rvieceli]

[member=72312]Rick Herrick[/member] let's step back for a moment and gather some additional information.

How big is your deck? The size of an aircraft carrier or a postage stamp?

How many boards do you need to replace?

Have you checked the structure underneath, joists beams posts to make sure they are sound?

If the underlying structure is sound, it might be a good time to think about redoing the whole surface in 5/4.You may have other boards involved in this insect damage just not as apparent or extensive.

Around here composite boards are running about $28 for 16 feet and pressure treated are $10-$14 in 5/4

Depending on how many boars you are replacing at $75 a board it might be cost effective to redo it.

Ron

 

[kevinculle]

I believe your question contains a false premise that staining the boards will somehow interfere with the insects invading them.  I'm not aware of any stain that will affect your insect problem in any positive way.  It seems that the pressure treated lumber you used wasn't adequately treated and needs to be replaced.

 

[Rick Herrick]

Cheese, Ron, Kevin.  Thank you for your posts.  I just realized I did not adequately state my case in the original post.  I'll start over.  My deck is 13 years old, 12x16 and about 15' off the ground.  4 years ago I realized I had some issues.  The floor joists and the rim joists are all 2x10 and other than 2 of them closest to the stairs, they are in good shape.  Those two had rotten spots, on the top, about 24" long and 3" in depth.  I knew I could not easily replace them so I did the 'sister' thing with some 2x6 material.

Most of the flooring boards (5/4) were in bad shape and splintering.  The railing on top was done in a manner (to my eyes) that I did not like so I made the decision to replace all stair treads and all flooring boards with 5/4 pressure treated.  I got these from a high quality, family owned lumber store and they have been perfect.  For all of the railing and balusters, I used 2x4 for framing and 2x6 for the top cap and 2x2 for the balusters.  All of this 2x material was bought from Lowes and HD and this is the stuff with the tag 'no rated for ground contact'.  That should have been my first clue. 

The top cap is the stuff I am having trouble with, that is the only thing I am trying to fix, other than finally pressure washing and getting a good solid, Valspar, stain on them.  I guess not being ground related has put out the sign to these big flying triangles to invade it.

The reason I want a full 16' board is both for one long section of the railing (other 16' side is against the house) top cap and both top caps for the stairs.  Currently I had to piece together the pieces and they have separated at the joints and look like crapola. 

Actually the length of the top cap for the stairs is closer to 16', 3" so I need to be creative, even with a full 16' board.

All of this was before I got semi serious about wood working and bought a lot of tools.  So for now, I am going to continue pressure washing and staining (a little at a time due to time constraints) and rethink the top cap issue.  No matter what, I will have joints in this top cap and I was trying to find a good piece of stone (8x8x2" roughly) I could set over each joint which would make it look a little better and keep some rain out of it.  I will investigate 5/4 material for top cap as well.  I may have to break out the Domino and figure out how to do some nice glued up domino joints to make my longer boards.  The 5/4 does sound better as it would also be 'less chunky' looking.  Trying to figure out how to put a little slope to each side (like a road way) to help drainage and not let water sit in the middle of a board for too long.

 

[Cheese]

Ok Rick...now it's making more sense.  [smile]

I wouldn't put stone over the joint unless it's just temporary to hide the joint. Anything you put on the joint will suck up moisture and turn it into a larger problem.

For that top cap, when I did my dad's deck rail, I brought over my Dewalt 735 planer and put a bevel on each side of it so it would shed water, that worked well.

 

[Rick Herrick]

Thats an interesting option Cheese.  What was the thickness of your Dad's material?  I am looking at roughly 72' lineal feet.  That seems like a lot of feeding into the planar (I have the 735 as well).  I imagine its a lot of passes just to bring one side down, let alone both. 

 

[Cheese]

It's really not bad at all Rick, my dad used a 2x6 so maybe 3-4 passes total. You don't need to put a lot of taper on it because once it's painted/sealed it sheds water easily. I think I used the typical 1/4" per foot taper used for plumbing. So a 3" (actually less than that) run needs to drop...you do the math. [smile] I'd run one side through, rotate it end for end & run the other side through. Drop the planer a little rinse & repeat.

 

[Rick Herrick]

[member=44099]Cheese[/member] When you did yours for your Dad, where did you start the 'drop'?  The middle of the board, dropping about 1/8-1/16 to the  edge?  How did you fasten the top cap?  I really want to stay away from fasteners on the top.  Wondering if some smaller, stainless, L brackets would work.  I can hide them under the cap and paint over them so they don't show.

 

[Cheese]

In the middle of the board Rick, like I said...you don't need a lot of taper. It came out really nice, 2x6 cedar.
My dad was an HVAC guy and making metal items was right up his alley, so he fabricated stainless L brackets. [smile] 
The deck needed in-fill panels for code purposes so he placed an L bracket on each side of the post and the in-fill panel covered it up when you were on the deck.

 

[rvieceli]

[member=44099]Cheese[/member] curious about how you accomplished the taper. Did you clamp a jig to the planer bed?

Ron

 

[Sparktrician]

Several years back, I replaced a bunch of wood on a friend's deck, including the top cap.  To help with drainage, I used my table saw to "tent" the top of the rail such that water drained off to both sides.  That meant that there was less material removed in total so the top rails were more resistant to warping.  I think I'd prefer that method over sloping it off to one side.  YMMV... 

 

[squall_line]

Several years back, I replaced a bunch of wood on a friend's deck, including the top cap.  To help with drainage, I used my table saw to "tent" the top of the rail such that water drained off to both sides.  That meant that there was less material removed in total so the top rails were more resistant to warping.  I think I'd prefer that method over sloping it off to one side.  YMMV...

It sounds like that's what [member=44099]Cheese[/member] did, as he mentioned he "put a bevel on both sides".

At least, I've been picturing it 'tented' by that description, but now I'm starting to doubt...