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.
Hey Chris,
This is a great site! Thanks for all the hard you have put into it and sharing it with us all!
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.
Glad to help. ENJOY your work!
Chris
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?
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
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
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
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
I love saving people money. My commission is 20%. Send the check to…
Glad to help. I hope your project went well.
Chris
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.
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