Painting Pressure Treated Lumber

[Shimon]

I've never painted pressure treated lumber before and was wondering if there are any tips. I have some "outdoor" oil based primer I was going to use and then regular outdoor white paint for a 4x4 post for a mailbox. I've heard some people apply a sealer to pressure treated wood to keep it from warping. Any tips?

 

[beenthere]

What is the wood that is pressure treated?

Most recommendations for pressure treated wood do not include paint. It will peel. Not aware of any sealer that will keep the wood from warping, and suspect it is 'advertising' claims that will be hard to back up with good results.

I suggest a penetrating stain, and stay away from any solid color that is applied to the surface.

I'd use the heartwood of such woods as cedar or redwood, and even Doug fir. Paint it with primer and two coats of good outdoor paint.

 

[RobS]

Our porch railing is all PT and painted. The biggest thing is to make sure it's dry. Our wood sat indoors (garage) for at least a year. It's been done and in the weather now for over two years with no problem.

I used a quality oil based primer and latex color coats. BTW, the year in the garage wasn't intentional, just didn't get a round tuit /forums/images/graemlins/smile.gif

 

[Solo]

Let the PT lumber dry for at least 6 months. My railings are all PT'ed and all painted, have been for seven years. Only minor touch up required. I used oil based primer and latex finish coat.

Solo

 

[Cliff_Johns]

</font><font color="blue" class="small">( Let the PT lumber dry for at least 6 months. . . . I used oil based primer and latex finish coat. )</font>

I think Solo got it nailed. The key thing is for it to be dry before you seal it. PT wood is very wet when you get it (usually) and no paint will survive over that wet a wood base (except heavy epoxy, but why do that).

As to warping. If it's Home Depot grade SYP (Southern Yellow Pine) it's likely to warp badly unless it's already nailed down fast. Warping may be reduced if you slow down the drying (If the wood will be exposed to warm sunshine which will dry the board unevenly. Slow down drying by putting on a thinned oilbase primer which can still breathe, but won't seal the wood completely, or store in a dry environment for a couple or three months per inch of thickness.

Best technique to prevent warping is to pick the wood carefully.

Cliff

 

[Shimon]

Thanks for the replies.

I meant to say "preservative" instead of "sealer" regarding the warping. I found that info here.

This piece of 4x4 is pretty new and still damp but it's perfectly straight (for now). Maybe I'll look through my big wood pile and see if I can find a dry piece.

 

[Nasty135]

Shimon, You can get PT stain in any color now-a -days and should be able to use it right away, Solids or Tints or maybe I'm missing something? Which is entirely possible..(I have a cold) /forums/images/graemlins/grin.gif

 

[GoodGuy]

It's been my understanding that if you use a oil primer you should use an oil base paint & the same with latex. Are you saying that you can mix oil base with latex products and visa versa ? For what it's worth & was always told to stain (not paint) PT wood, it would be nice to be able to paint it & have it last.

 

[Cliff_Johns]

</font><font color="blue" class="small">( It's been my understanding that if you use a oil primer you should use an oil base paint & the same with latex. Are you saying that you can mix oil base with latex products and visa versa ? )</font>

People say not to mix uses at all because people have trouble remembering which can be put over which, and so they just tell you not to do either. Latex may be put over an oil based primer. The primer must be allowed to dry completely before applying the finish coats.


Cliff

 

[GoodGuy]

Can you put an Oil Based Paint over a Latex Primer ?