Pressure treated wood...

A couple of questions of about deck building and pressure treated wood. I'm getting ready to have a deck built using Trex for the flooring and railing. It's a pretty big size deck, about 1700 sf, so I'm trying to find ways to extend it's life:

1. Any thoughts on whether or not painting the pressure treated wood used for the deck supporting structure will siginificantly increase its life?

2. Does anyone know of any reason not to paint pressure treated wood? Specifically, that wood treated for deck building. I've had a contractor tell me it wasn't adviseable because the chemicals the wood is treated with need to breath.

Thanks,

Stu

Take the contractors advice. Don't paint pressure treated wood.

That pressure treated wood needs to gas-off for a few months. You'ld be surprised at how wet some ofthat stuff is when it gets stocked at HD & Lowes. That being said, wait about 6 months after construction, and then STAIN it, or use a TINTED water sealer.

Maurice

I'm with my Buddy Steve. That stuff is dripping wet off the shelf and any paint will pop right off not to mention trap the moisture in.

Green or brown are your chioces of color here.

No paint it is, at least for 6 months. Thanks fellas.

Stu

Take care working with that stuff...wash your hands, be careful about breathing in the sawdust, too. Nasty crap....

If it is new pressure treated, be careful with your fasteners. I understand that this year's pressure treated wood is terribly corrosive, although arsenic free. I think stainless steel is recommended, although hot dipped galv. is acceptable. I am not a framer or deck guy, but just passing on some info I have bumped into along the way.
Alan

Never paint PT wood...it's not a good idea.

It's also not a good idea to use Trex. They only guarantee Trex for TEN years....get Ipe for less money, it's guarantee runs 25-40 years depending on where you get it.

Be aware that Trex really should be framed with 12" centers since it's so flexible. It also doesn't like heat. I have been dead set against any composite since they appeared...they have no character.

You can get 3/4" Ipe and frame it on 16" centers using PT lumber. Seal it with Penofin or Cabot's Australian Timber Oil before decking.

PS...all the chemicals drain out of PT lumber in 6-8 weeks...no need to wait 6 months to treat if used as decking. As far as framing goes, there's really no need to treat it further except on the ends and you can use Anchor Seal for that.

In my business I build about 15-20 decks per year...feel free to PM me with any other Q's you might have, be happy to help out.

Drains out?? Where does it go?? Do you mean evaporate??

So what is the point of PT if the chemicals leave...is it still protected?

I just had a very depressing termite inspection in which most of the problems were caused by the use of untreated wood in the construction of my new chimney. The wood has been there about 8 years and I guess the termites have been having a field day.

Never use untreated wood for constructing anything other than fine woodworking. If using treated wood, make sure the cut ends are treated at the site. If you must use untreated wood, plan on tenting the house.

I have successfully used a stain on treated wood and that does not seem to affect the "treatment". Wait awhile until it dries completely and then go for it.

You are correct about the corrosive problem. It is actually electrolysis. The two dissimillar metals (steel and copper) react to each other and cause the nails to disolve. There are several nails you can use. The best option is stainless, but they are far from cheap! You can also use aluminum nails in some situations. There are also some specislly formulated nails for ACQ lumber. I bought a box from Bostich for my framing gun and it ran me $45 for 2000 nails. Make sure that you also use PT rated hangers and brackets. Make sure you wear a dust mask when cutting the wood. One last thing. Go to a good paint shop and get a can of green treatment and brush it on any cut ends. This will help protect the deck.

Chris,

It actually evaporates a little at a time. It's the excess chemicals from the pressure chamber. Enough remains in the lumber to protect it from the elements as long as it's sealed after drying.