Staining Pressure Treated Lumber Lumber Talk.com: Professional-Level information and how-to-build articles for wood, timber, and lumber professionals and users. Staining Pressure Treated Lumber » Lumber Talk
By Chris | November 4, 2008 - 9:02 am - Posted in Decks & Fences, How To, Treated Wood

staining pressure treated lumber I regularly get questions about staining pressure treated lumber so here are some answers to as many of those questions as I can think of now. Before you read on, understand that staining or painting pressure treated lumber is just like staining untreated lumber. The main thing is that the wood needs to be clean and dry.

Can I stain pressure treated lumber?
Yes. You can stain pressure treated lumber as long as the wood is dry.

Why do I have to wait before staining pressure treated lumber?
The pressure treating process involves using a water-based solution to carry the treatment chemicals into the fibers of the lumber while under pressure. The process leaves the wood wet. If you want wood that is already dry, purchase KDAT lumber (KDAT = Kiln Dried After Treatment). KDAT is usually #1 and, yes, it costs more.

What are the consequences of staining pressure treated wood before it’s dry?
The stain or paint will probably bubble a little AND locking moisture into the wood might create a great place for fungus or rot to take hold and destroy some boards.

How long should I wait (allow the wood to dry) before staining pressure treated lumber?
It depends (of course). In a sunny, hot, and windy climate where it never rains your pressure treated lumber will probably be dry in a few weeks. In a cold and muggy climate (Seattle, for instance) it will take months for your wood to dry.

Some professionals recommend building whatever you are building and waiting about six months before staining pressure treated lumber. Then, stain the lumber after a few weeks of warm sunny weather. This is long enough for the wood to stabilize and for the water from treatment to evaporate. Remember to sweep and/or dust before applying the stain or paint.

Read further to learn about drying lumber yourself…

What kind of stain should I use for pressure treated lumber?
There are many stains and paints on the market. My favorites are based on working with lumber yards and seeing results from Consumer Reports. So, I like Cabot and Wolman brands. Many people thing Thompsons is the best because their marketing is the best. Many professionals completely disagree with the idea that Thompsons is any good at all. I am not saying anything about it – I’m just sayin’. The choice between water-based and oil-based stains is up to you. Read the backs of the cans. Back to staining pressure treated wood…

How should I stain pressure treated lumber? Or, how should I apply the stain?
Read the can because it varies with some stains but most stains can be applied with a brush, sprayer, or sponge. You will probably find a sprayer to be the easiest method.

How can I speed up the lumber drying process and stain my lumber sooner?
The best way is to buy kiln dried lumber (KDAT) in the first place. If you don’t want to do that…

You can dry lumber yourself but you need to be concerned about warping.

Ideally, you should stack the lumber on “sticks”, in the same way wood is stacked for kiln drying, and then strap the bundle to keep in straight. To do this, place a few small (1×1 or 2×2) sticks between each layer of lumber (perpendicular to the lumber and spaced about 3 feet apart) allowing for air flow between the layers. Then wrap a few straps around the lumber and make them tight. This allows air to reach all sides of the lumber while applying pressure to the lumber and minimizing the chance of warping. Warping is caused by the movement of moisture in and out of wood. You need to stabilize/support the wood while it dries. To take it to another level, point a box fan (or two) at the side of the bundle to speed up the flow of air across the lumber. If you set this up in your garage or some dry covered area your lumber will probably be adequately dry in a few weeks.

Should I stain pressure treated lumber yearly?
The answer is simple and goes something like this. If you want your deck/gazebo/arbor/whatever to look better for longer you should stain it on a yearly, or regular, basis. Of course, putting a protective stain or other coating on wood will make it last longer and look better while it lasts.

Staining pressure treated lumber is not rocket science. In fact, there is nothing remotely complicated about it but it does take time and if you don’t do it properly, you’ll mess it all up. If I did not make this point obvious enough above then let me say it again here:

Treated wood must be dry before you stain or paint it.

Enjoy your project. Wear gloves. Wear goggles. Be careful with tools. Work in ventilated areas.

37 Comments

  1. November 6, 2008 @ 6:54 am


    Hey Chris,
    This is a great site! Thanks for all the hard you have put into it and sharing it with us all!

    Posted by scott
  2. February 12, 2009 @ 12:01 pm


    Your comments are very helpful. I had a pressure treated wood deck built in October 2008 and have been searching for information on stains that can be used on the decking. Since the weather here is fairly mild I feel that maybe the deck will be ready to stain next month. I will certainly follow the advice given and read the label on the stain I choose to use. I will also look into your suggestion of the brands you suggest. Thank you again for the infomation.

    Posted by Betty
  3. February 13, 2009 @ 10:37 am


    Glad to help. ENJOY your work!

    Chris

    Posted by Chris
  4. March 19, 2009 @ 9:19 am


    Hi Chris–thank you for all the helpful suggestions. I have read on other sites that new pressure treated wood should be ‘sealed’ immediately. Wouldn’t the sealant keep the moisture in the wood rather than allowing it to evaporate?

    Also, the wood our carpenter is using was kiln dried prior to the pressure treatment. Does this affect the waiting time to stain or paint the wood?

    Posted by Amy
  5. March 25, 2009 @ 3:50 pm


    Hi Amy,

    I agree with you. The professional I hang around – from lumberfolks to deck builders – say to wait until the wood dries.

    Kiln dried BEFORE pressure treatment? Or after? It is common for wood to be dried AFTER. Kiln drying before treatment is sometimes done to ensure deep penetration of the chemicals into the fibers of the wood by removing the existing water to make space for the water-borne preservatives.

    I don’t think it would affect the waiting time. The big factors are still going to be rain, sun, temperature, and humidity.

    Take care and thanks for writing.

    Chris

    Posted by Chris
  6. April 22, 2009 @ 5:58 pm


    Hello Chris,

    Does “new”(installed oct 2008) treated decking need to be prepped prior to staining?
    Someone mentioned to me that “mill glaze” will have the fibers “smashed down” and
    the stain won’t penetrate properly. Is there any truth to that?

    Thank you,
    George

    Posted by George
  7. April 23, 2009 @ 4:07 pm


    Mill glaze is really only an issue with redwood and cedar when they are planed with dull blades. Treated pine, which has vertical grains, does not really have a problem with mill glaze.

    Always sweep thoroughly and make sure the deck is clear of any dirt, dust, debris, or moisture before staining it.

    That’s it. Good question.

    Take care,
    Chris

    Posted by Chris
  8. April 23, 2009 @ 5:53 pm


    Thanks alot Chris,

    You just saved me a day and some money, with the weather here in
    the Northeast looking good thru next week, looks like I can get some staing
    done this weekend 🙂

    Thanks again,
    George

    Posted by George
  9. April 28, 2009 @ 2:58 pm


    I love saving people money. My commission is 20%. Send the check to… 🙂 Glad to help. I hope your project went well.

    Chris

    Posted by Chris
  10. May 12, 2009 @ 2:00 pm


    I just had a screened in porch built with treated wood. Should I seal it now or should I skip sealing it and wait a few months and then stain it?

    What stain would you recommend? Thanks.

    Posted by Alan
  11. May 13, 2009 @ 10:20 pm


    Hi Alan,

    This is just what I would do – skip the seal and stain later. I like Cabot stains – nice colors, applies well, protects well.

    Enjoy!
    Chris

    Posted by Chris
  12. August 8, 2010 @ 7:01 pm


    Hi Chris,

    I just found this website, after searching for weeks. Just had a new deck completed, vinyl railings, PT (pine?) floor. Looks like I’ll have to wait until spring to stain? And is semi-transparent better than solid? (though I like the look of solid better wtih the vinyl railing) and what about semi-solid? I already decided on Cabot. Thanks for your easy to understand info.

    Posted by Donna
  13. August 13, 2010 @ 6:32 am


    my client wants me to seal the underside of the decking boards before i screw them down to prevent warping. although i am willing to do this, i feel it is unnecessary and will have little effect on keeping a predisposed board from warping. the deck will receive a semi-transparent stain and she has asked me to use thomson’s water seal on the bottom-side. what do you think?

    Posted by bob baldwin
  14. September 18, 2010 @ 4:44 pm


    I agree that it’s not necessary to coat the underside so politely and authoritatively state your professional opinion and give your advice. Then, make your client happy by charging to do the task she requested.

    In my experience, this path leads to:

    – clear conscience because of your honesty
    – a structure that is certainly no worse off (and maybe even better)
    – happy client who appreciates your honesty

    Posted by Chris
  15. September 18, 2010 @ 4:49 pm


    Hey Donna,

    I don’t know about waiting until spring. You just need to make sure the wood is dry. A few weeks of hot days with no rain and a little breeze for good measure should be good for decking.

    Use whatever color you want. Color is required for UV protection which is going to give most of your fade resistance but it all gives great rot/decay protection.

    Thanks for reading!

    Chris

    Posted by Chris
  16. July 23, 2011 @ 9:37 pm


    I used 4x8s on the main parts of my arbor & the wood shows green but looks dry should i wait a few more weeks ,its hot here in dallas

    Posted by Darrell Scott
  17. August 20, 2011 @ 6:40 am


    Hi CHris

    We just had our raised sundeck replaced. We used PT wood with six-inch posts. After about three weeks of extremely hot weather (90 to 105 degrees), the posts have started cracking pretty bad. The contractor said we should use Sherwin Williams solid colored Deckscapes and stain it now to prevent further cracks. I am wondering if the posts should be replaced or should we use the stain and hope for the best.

    Posted by Donna Wasson
  18. August 23, 2011 @ 7:39 am


    I recently built a deck using pressure treated wood in July of this year. I wanted to use Cabot’s solid stain but was told that since the deck is new and is made of pressure treated wood that it would flake and is not recommended. I would greatly appreciate any insight you can give in this matter.

    Posted by Susan
  19. September 14, 2011 @ 7:16 am


    Hi Chris, I’m new to the whole do-it-yourself circuit, but my father and I finally complete my deck a days ago. After reading your blog, I’ll probably wait a couple of months before staining it. However, I do have a rather simple question. I was prepared to stain and seal the deck Is this a waist of time and money? Does the stain also acts as a sealant

    Posted by Robert penn
  20. September 16, 2011 @ 10:30 am


    This deserves one of those “it depends” kind of responses. In short, I generally prefer stain because it allows the wood to “breathe” while protecting it from UV and moisture. Seal offers better protection from moisture assuming the wood is adequately dry when you apply the seal.

    Posted by Chris
  21. September 16, 2011 @ 10:34 am


    Save your money and energy to re-stain the deck again next year. Reapplication of the stain every year or two is what will make your deck last a long time. Regular maintenance and care is the most important thing.

    Posted by Chris
  22. September 16, 2011 @ 10:40 am


    Too late for Darrel on this but it’s a good question… The wood will probably still appear green for a while after it is dry but, yeah, you should generally wait a while to make sure the wood is dry unless you bought it KDAT (Kiln Dried After Treatment), which is not common for 4×8’s unless requested.

    Posted by Chris
  23. September 16, 2011 @ 10:50 am


    Donna,

    EXCELLENT QUESTION. Those are probably CHECKS — not cracks. Checking is generally not a structural issue but, of course, you might not find it aesthetically pleasing, either. It is caused by rapid drying along with the fact that the outside of the pole/lumber/beam dries faster than the core.

    If you replace the posts you will have to take steps so the new posts do not check (or only check minimally).

    To avoid checking, your posts need to be dried slowly. For instance, you could store them in your garage for a month or two before installing them.

    Stain might help.

    Important: I am not looking at the posts so JUST IN CASE. Have someone take a good look at these. If they are cracks, then you might have a structural issue and someone could get hurt. If they are checks, you are probably fine. Either way, please get somone to confirm the safety because “that guy on LumberTalk.com is not responsible for actions taken as a result of anything written on this website.” 🙂 Seriously, make sure it’s safe. That goes for all of you.

    Posted by Chris
  24. November 1, 2011 @ 6:35 pm


    Hi Chris,

    I live in Michigan and is having a front porch completed with pressure treated wood. We have been having quite a bit of rain this fall, and the temperature right now is averaging around 50 degrees during the day and between 30-40 degrees at night. My question is, is it too late to stain the wood? Should I just wait until the summer?

    Posted by Kevin
  25. October 13, 2012 @ 8:49 am


    Hi Chris,

    I just finished replacing the old boards on my deck, but it is October and the nights are dropping below 50 degrees. Will it hurt the wood if it is not stained or sealed before the winter sets in? It is pressure treated wood.

    Thanks,
    Shawn

    Posted by Shawn
  26. October 17, 2012 @ 10:11 pm


    Hi Shawn. The word around town is that snow and ice is easier on treated wood than sealing it before it is dry. I’d wait. Why are staining your deck at night in 50 degree temps, anyway? 🙂

    Posted by Chris
  27. October 17, 2012 @ 10:24 pm


    I’d wait until summer but the temperature tolerances vary a little from stain to stain. The back of the can will be your best guide. The most important thing with staining is to make sure the wood is dry. If you bought it wet (not KDAT) or if the humidity is too high, you need to wait. Thanks for writing!

    Posted by Chris
  28. February 11, 2013 @ 11:47 am


    Is it advisable to stain/seal the tongue and groove before installing T&G KDAT pressure treated boards?

    Posted by WD2
  29. March 13, 2013 @ 11:27 am


    Hi Chris,
    I have a deck being built with some cedar(p0sts), cypress (railing and spindles) and PTP flooring. Will a solid color paint stain ahdere okay to the cedar and cypress without a primer? Also, I was told that the cedar and cypress are okay to stain immediatley since they are not Pressure Treated?

    Thanks in advnace,

    Posted by Jaye
  30. April 11, 2013 @ 9:19 am


    I replaced 2×12 rotted Douglas fir porch boards with 2×12 PT. these boards lay flat on top of a knee wall that you can sit on. My question is this….how long should I wait to paint these 2×12’s? Thanks

    Posted by Paul
  31. April 24, 2013 @ 2:12 pm


    You say ” Many people thing Thompsons is… ” You mean THINK.

    Posted by DJS
  32. May 7, 2013 @ 2:18 pm


    I thinG you are right.

    Posted by Chris
  33. May 7, 2013 @ 2:22 pm


    Depends on weather, humidity, how dry they were when you bought them, and everything else that affects how dry they are — because they need to be dry before you paint them. Expect 2 to 6 weeks.

    Posted by Chris
  34. May 7, 2013 @ 2:26 pm


    Hi Jaye,

    This reply is getting to you way late but the real answer is that when to paint is more about how dry the wood is, not really about whether it is pressure treated. If the cedar and cypress are dry, you can stain or paint them immediately. If pressure treated, you can stain or paint immediately after they are dry.

    Whether or not to use a primer depends on the specific stain.

    Posted by Chris
  35. May 7, 2013 @ 2:27 pm


    I would seal first then wait until the boards are thoroughly dry before installing.

    Posted by Chris
  36. May 20, 2013 @ 11:10 pm


    deck survival..a friend’s deck…. treated wood was stained, it peeled off
    next came a second stain… that too broke down, followed by exterior paint that is now peeling off. unique circumstances we are down wind from a pulp/paper mill
    deck temperatures reach 50 c in summer heat

    my suggestion is sand off as much as possible and oil. is this a viable solution?
    after checking with neighbors she is not alone with her problem

    any suggestions would be much appreciated

    thank you for your time

    bob orr
    crofton bc

    Posted by bob
  37. May 21, 2013 @ 8:17 am


    Wow. First, I might move. If it is doing that to your deck stain, I’d be concerned about, well, everything else. I’ve got family who lives near a paper mill and have never heard about this kind of thing. BUT, I think you have a great idea with using oil. I am surprised the stain peeled off, though. Sand, maybe even pressure wash (lightly), before re-applying the next stain. Try something clear.

    Posted by Chris

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