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When to seal new pressure treated deck?

We have been talking to the home improvement & paint stores and seems like everyone has various ideas. Anywhere from right away to 6 months or a year. We live in northern Illinois.

Thanks in advance for any assistance or direction to reference sources.


Re: When to seal new pressure treated deck?

If you just finished your deck and the wood used to do the deck was not dry, I suggest you to wait next spring...

If the wood you use was dry you should seal it right now!

this is my humble opinion...

Re: When to seal new pressure treated deck?

if i'm not mistaken, you can seal or stain a deck right away. if you are gong to "paint" pressure treated wood then you should wait 6 months to a year.

Re: When to seal new pressure treated deck?

I recently wrote a good article on these same questions I come into when building decks. If you follow this link, it will direct you to the article I wrote on my home improvement blog

Re: When to seal new pressure treated deck?

Most products for sealing decks list guidelines as to when and how to apply their products!

Calcats ;)

Re: When to seal new pressure treated deck?

Had the same question a year ago. Asked an employee at a lumber/hardware/paint store for advice and was told to wait one year for wood to season. I waited and sealed the deck 12 months later, almost to the day. Now several pieces are warping.

I got online and found this article written in 1992 about sealing and/or painting PT wood. Answered all my questions. I can't send a link to you because it is in .pdf format and I don't know how. If you have Adobe Reader installed it is ross92a.pdf. Article was written for American Painting Contractor in 1992 by by Alan Ross, Steven Bussjaeger, Richard Carlson, and William Feist; title of article is Professional Finishing of CCA Pressure Treated Wood.

I found the article most helpful.

Re: When to seal new pressure treated deck?

Excellent article. Very informative. So a deck SHOULD be finished within 2-3 weeks after installation. And use a GOOD quality product. Don't skimp on this step or you'll pay for it later. :cool:

Re: When to seal new pressure treated deck?

My two cents:

It will not damage any of the common decking materials to sit for several months with out sealing. Indeed, it could well be beneficial, especially by cedar and redwood, which often come with a "mill glaze" that will go away with aging in the rain and sun. Also, pressure treated wood is saturated with rot resistant chemicals in a water solution under pressure. The water goes deep into the grain of the wood and can often be felt by touch and weight. Obviously, it is not good to seal in wet wood, especially if the product is oil based. Oil and water don't mix!

Ideally, you want the moisture content to be in the single digits. To this end, the best time is actually in the late summer in most climates, after the summers drying heat and before the precipitation of the winter. This is especially so here in the Pacific NorthWest where I live. In reality, most homeowners want to be out partying on a nice freshly stained/sealed deck during the summer.

I am not an advocate of using full bodied flooring paints on decks. If you can't keep wood from getting wet, don't put a finish on it that will restrict the moister from migrating to the atmosphere. A heavy paint film will restrict the drying more so than a solid decking stain. If the moisture can't exit slowly through the finish, it will peel off!

Unfortunately, the nature of the construction of decks allows for many areas of water entry: unfinished decking board bottoms sitting on
unsealed joists, hundreds of over-torqued screws sitting in little craters that hold water, butt joints that will never again be able to be sealed after construction, cracks due to general aging and drying, etc. The gist is, if you can't keep the moisture out, don't seal it in with a non-permeable paint or varnish.

Generally, the more pigment in a stain, the more the protection of the wood. It is the pigment which blocks the UV rays of the sun. Clear products are the poorest.

Oil stains are least likely to peel because they do not form a heavy film on the surface. They breathe better. The down side is that every oil product I know of calls for almost yearly re-sealing.

The water based products tend to hold up longer, but still must be periodically re-coated, and if neglected, must be stripped because of irregular peeling. An oil product will never peel, per se.

Whatever you treat your deck with, yearly cleaning and removal of mildew and algae is highly advisable to increase its longevity. Rot,after all, is merely fungus eating away at the cellulose in the wood.
a clean deck is a happy deck! :)

I am kind of a contrarian. An uncoated deck that is throughly cleaned periodically, will last just as long as a deck that has been repeatedly stained and sealed. Of course, it will not look quite as good, will dry out sooner and get cracks, will stain when someone spills the red wine on it, etc. But it will resist rot just as long! Indeed, sealing will a heavy bodied paint can actually increase rotting!

Graying of the wood can actually be kept at bay by periodically cleaning with an oxalic acid containing deck cleaner.

I elected to put in decorative concrete patios here in Oregon - a lot less maintenance! Ironically, back in Illinois, I would have avoided concrete because of frost heaving. Also, the extreme cold of the Mid-West and the relatively dry winters are much easier on wooden decks than is Oregons' long, relatively warm and wet winters.

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