Painting pressure treated lumber

[Existential Angst]

I've read you have to delay painting PT lumber from everywhere from two weeks to a year. Latex paint... What's the deal?

And, how does one tell if PT wood is ready to be painted? It feels quite wet from the lumberyard/HD, but seems much drier in a cupla days. Does rain further extend the wait? Does a sprayer allow you paint sooner than brushing/rolling??

Also, just curious: Will non-PT wood last as long as PT wood (outside, of course), if it thoroughly painted? In the northeast. Any special painting methods required?

[-MIKE-]

I don't know how long you need to wait.

As for paint... might I suggest an opaque stain. Depending on the concentration and size of pigment, it will get deeper into the grain of the wood than paint, but from a distance looks like paint. It lasts a lot longer than paint and fades instead of flaking/peeling.

Last porch I built, I used PT lumber with a white opaque stain. Up close you could still see the grain of the wood, which was an attractive feature. From the road, it looked like a newly painted white porch. It stayed bright white for several years.

[Leon]

PT lumber is typically very very high in moisture content. Read that as often soaking wet. Paint needs to stay dry on the side that it adheres to a surface. If moisture saturates the surface under the paint the paint will fail.

Use a moisture meter or wait at least year. Method of application has nothing to do with how long the paint will last on a poor surface.

That said some better lumber yards, not home centers, carry kiln dried PT lumber, this is what you want if you want to paint right away.

That will depend on the wood. Fur, SYP, mahogany, ipe, cedar are a few commonly used woods for out door use with no protection or paint.

[Existential Angst]

Good idear, I'll look into it. I wouldn't use white stain tho, something red-ish -- which fades quickly in ultraviolet. Is there an exterior polyurethane that can protect pigments form UV? Or are there UV-impervious pigments?

[-MIKE-]

I just brought up white because it's the color we used on our porch. I'm no expert but in my experience nothing will stand up to UV... for very long. I'm sure a good paint shop could tell you what's out there that works best. Maintaining outdoor woodwork has always been arduous. Engineered composite lumber has held up to UV so far, as advertised, from what I can tell.

[Nova]

According to the Forest Products Lab:

"Contrary to the belief of many consumer's and paint companies, it is not necessary to allow newly installed pressure-treated wood to weather or season for long periods of time before applying a coating. Most newly built CCA treated wood decks can band should be protected with a water repellent, toner or semi-transparent stain as soon as possible after construction. Research has shown that exposing unprotected wood to weathering for even short periods of time can cause surface damage. This damaged surface reduces the ability of the wood to hold onto subsequently applied coatings?a situation that can ultimately lead to premature coatings failure. This, unless the new treated wood is still very wet, it should be coated as soon as possible after deck construction. If the wood is obviously wet, no more than 2-3 weeks of air-drying should be allowed before a coating is applied."

[Leon]

mentioned above are not opaque, as paint is. So I would surmise that paint would not be a good coating for new PT wood.

[Nova]

I really can't think of anyone I know who actually painted and entire deck. This summer my neighbor did paint the railings and pergola on his deck. I can let you know how it holds up in a few years. I would guess given, the higher amount of solids in paint, that it will hold up better than stain.

[Ed Pawlowski]

Contains a lot of moisture and the paint will peel. I'd wait a year or so.

Not really, the rain does not get absorbed because the PT is saturated with other chemicals.

Nope, peeling is peeling.

Look at the oldest house in your town. Chances are it is from the

1700's and if painted and cared for, still in good condition.

Wait for the snow to melt. Read the can, most paints should be 50 degrees or more, a few can tolerate 40 degrees.

[bob haller]

never paint PT wood, as it will just peel the PT chemicals prevent paint adhesion.........

and you far better off using composite decking because over time PT wood still fails.......

[krw]

I painted all the (PT) railings on my deck and front porch on my VT house. Peeling was a major problem and I had to repaint every couple of years. Stain didn't last any longer.

[Existential Angst]

Hmmmm..... how bout if I torched the wood, to sort of surface-singe it? Would that help adhesion?

[Ed Pawlowski]

Composite had its share of failures in the past too. Don't go for the cheapest stuff if you go that way.

There are also many woods that made good decks, but are pricey too. Mahogany, ipe, etc. I used tiger wood a couple of months back.

[Dave]

On Sat, 29 Sep 2012 17:41:18 -0400, " [e-mail]"

Which would make sense since PT wood is already engorged with chemical preservatives. There isn't any available wood fibre left for the paint to soak in and adhere to it.

[Leon]

The OP mentioned painting PT lumber. Not sure in the North but exterior paints tend to hold up very well compared to stains. Still they need to be applied to a suitable surface, a dry one. IIRC Hardi strongly suggests a primer on their products to block moisture from coming in contact with the back side of the paint surface. I personally have not had great results with painting fresh PT lumber but do agree that the longer you wait the trade off of a less than desirable surface, appearance wise becomes another problem in itself.

[Leon]

Actually have never had a problem with paint peeling on PT provided the lumber was "dry".

Agreed.

[Dave]

Hell, everything fails given enough time. Let's put some quantifiable time numbers on that failure rate.

[thunder]

If you are going through that trouble, why not use KDAT instead? Kiln Dried After Treatment

[bob haller]

buy from a major long term manufacturer...........

honestly i DONT LIKE WOOD for long term outdoor use.....

concrete doesnt cost that much more and lasts far longer.......

[Larry Jaques]

Cement board like Hardi should be painted on all six sides prior to going up on a house. Ditto wood products.

-- Never trouble another for what you can do for yourself. -- Thomas Jefferson