LumberJocks

Treatment for pressure treated lumber

  • Advertise with us

« back to Wood & Lumber forum

Forum topic by deadherring posted 08-15-2017 06:50 PM 406 views 0 times favorited 13 replies Add to Favorites Watch
View deadherring's profile

deadherring

59 posts in 1400 days


08-15-2017 06:50 PM

Hey all,

I just finished a project of several outdoor couches, a small cocktail table and two coffee tables. I’m pretty happy with how it came out, it is one of those things where my wife and I said—why didn’t we do this ages ago, it’s transformed our outdoor space. (coffee tables not included in pic below, just finished them)

Everything is made from big-box pressure treated lumber. My question is , I’d like this stuff to last for ages. From what I’ve read you shouldn’t treat pressure treated lumber until it dries out and that I should plan on waiting a year during which time it will gray. Then I should sand it and apply a finish. Is that right? I’m in northern NJ if climate matters.

If yes, do i need to be concerned with it rotting or deteriorating between now and when i apply the finish? What finish gives me the best shot of long term protection against the elements? I’ve heard Thomsons water seal?

Thanks!

Nathan


13 replies so far

View Fred Hargis's profile

Fred Hargis

4614 posts in 2250 days


#1 posted 08-15-2017 07:03 PM

I’d use paint, but that’s just for appearance. Treated lumber will last a very long time without anything. It does need to be dry before you paint it, then prime with a good primer (preferably an oil based) and paint with a 100% acrylic exterior paint. But that’s just me…..

-- Our village hasn't lost it's idiot, he was elected to congress.

View RW19's profile

RW19

1 post in 41 days


#2 posted 08-15-2017 07:44 PM

I built this a few months ago. I let it dry for a month then stained it with some good ole minwax and then paint/weathered it with some good PPG exterior paint. It was my first time doing that kind of finish and I’m pretty happy with it.

View woodbutcherbynight's profile

woodbutcherbynight

3312 posts in 2166 days


#3 posted 08-17-2017 04:40 AM

Paint, use a oil based primer and it will last a long time. Do let it dry out before beginning the entire process.

-- Live to tell the stories, they sound better that way.

View rwe2156's profile

rwe2156

2637 posts in 1237 days


#4 posted 08-17-2017 01:24 PM

Yes you can paint PT lumber but it has to be completely dry. I’ve done it many times with trim on houses.

If it is outside in the weather it will never completely dry.

If this is the case, I would simply coat with a decking sealer.

-- Everything is a prototype thats why its one of a kind!!

View deadherring's profile

deadherring

59 posts in 1400 days


#5 posted 08-17-2017 04:32 PM

Thanks for the suggestions. The Mrs. likes the natural wood look, so I think Thomsons water seal is going to be the way I go.

About how long do I need to wait before applying? A year? Maybe next spring?

Also, do I sand before applying?

@woodbutcherbynight Cool stairs. What would be the reason you need to regularly get on the roof?

View Fred Hargis's profile

Fred Hargis

4614 posts in 2250 days


#6 posted 08-17-2017 04:56 PM

1) when the wood dries a little, it’s probably ready now.
2) No, but you might want to clean it a little if any crap and such fell on it.

-- Our village hasn't lost it's idiot, he was elected to congress.

View tmasondarnell's profile

tmasondarnell

53 posts in 1546 days


#7 posted 08-17-2017 05:13 PM

Nathan,

I am a little confused by what your question is and what are you concerned about.

The 4×6 PT lumber does not need anything done to it for protection, even with full ground contact.

Adding Thompson water seal will not add any additional protection to the Alkaline Copper Quaternary(ACG) that was driven into the wood fibers under pressure. Most likely the Thompsons will bead up and run off. You will not be hurting anything, but you will be wasting your money.

Painting will offer the best protection against UV damage.

View papadan's profile

papadan

3584 posts in 3125 days


#8 posted 08-17-2017 05:14 PM

Let it dry for about one month, sand all body contact areas, (arms, lower fronts) to prevent splinters. soak down with Thompsons water seal and let dry for 24 hours. I use a pump garden sprayer to apply with. Every spring, lightly sand contact areas and spray with Thompsons.

-- Artificial intelligence is no match for natural stupidity!

View deadherring's profile

deadherring

59 posts in 1400 days


#9 posted 08-17-2017 08:19 PM

OK, so it sounds like the rough consensus is if applying Thomsons Water seal, let it dry for about a month and reapply every year?

Are there any things to look for when looking at the wood to determine dry enough to have the seal applied?

Thanks.

View Abter's profile

Abter

41 posts in 384 days


#10 posted 08-17-2017 10:45 PM

A $20 moisture meter will go a long way, especially in 1” or 2” stock. easy to buy at most big box stores or amazon. 12% is usual guidance for what you want. Avoid over 20%

Big box PT can be REAL wet. I’ve had juice running out of it from drilling a pilot hole. Very fresh PT runs about 35% or more.

Drying time will vary enormously. A high humidity climate in the shade…it might take forever. In the Mojave desert in the sun….lets just say less.

-- "Many men fish all their lives without ever realizing that it is not the fish they are after." {often mis-quoted as by H.D. Thoreau}

View dhazelton's profile

dhazelton

2591 posts in 2053 days


#11 posted 08-17-2017 11:00 PM

Thompsons doesn’t hold up to weather long. Do it twice a year. You may want to tip your couches over and smear something on the end grain of the legs so it doesn’t wick water up.

View papadan's profile

papadan

3584 posts in 3125 days


#12 posted 08-18-2017 12:38 AM



OK, so it sounds like the rough consensus is if applying Thomsons Water seal, let it dry for about a month and reapply every year?

Are there any things to look for when looking at the wood to determine dry enough to have the seal applied?

Thanks.

- deadherring


Just feel the wood, if it is cool or damp to the touch it’s too wet. It will feel warm and dry when ready. The purpose of the Thompsons is to prevent absorption of moisture. Once a year is plenty and the wood will weather out to a nice gray like you want.

-- Artificial intelligence is no match for natural stupidity!

View woodbutcherbynight's profile

woodbutcherbynight

3312 posts in 2166 days


#13 posted 08-18-2017 01:47 AM


@woodbutcherbynight Cool stairs. What would be the reason you need to regularly get on the roof?

- deadherring

Clean the gutters, install lights, minor repairs to roof, pressure washing, all things I did not want to get out a ladder for. As my shop wall is 4 ft buried into the landscape this staircase allows access to the shop roof and from that roof the entire house behind it. Not practical for most but with the lay of the land it works well.

-- Live to tell the stories, they sound better that way.

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com