# Pressure treated wood does or does not need to be painted????



## stanlam (Aug 25, 2009)

I'm very confused about this. 90% of the articles I read say pressure treated wood must be painted or stained. However, I see pressure treated wood on peoples fences, decks, and walkways that was never treated or painted. Does anybody know the truth?

I want to built a deck platform, but I don't want to paint or stain most of it. I only want to paint the wood that people can see on top of the deck. The framing and the underside of the deck I just want to leave it unpainted and unstained.


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## Just Bill (Dec 21, 2008)

Does it HAVE to be painted/stained, no. Should it be, yes. PT wood has a tendency to split and check as the chemicals dry out. Stains, better than paint, slow this normal aging. Stains soak into the surface, where most paints are just a top coating, so stains protect better. And solid stains work better to block UV rays than semi-transparent stains.


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## vote4Pedro (Jul 23, 2010)

this is just exterior use only right? i have some PT wood inside my walls ,i've just built for load bearing, that is not stained


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## Ron6519 (Mar 28, 2007)

vote4Pedro said:


> this is just exterior use only right? i have some PT wood inside my walls ,i've just built for load bearing, that is not stained


Pressure treated wood for interior use is for sill /bottom plates only. No need for surface applications.
Ron


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## Joe Carola (Apr 14, 2006)

stanlam said:


> I'm very confused about this. 90% of the articles I read say pressure treated wood must be painted or stained. However, I see pressure treated wood on peoples fences, decks, and walkways that was never treated or painted. Does anybody know the truth?
> 
> I want to built a deck platform, but I don't want to paint or stain most of it. I only want to paint the wood that people can see on top of the deck. The framing and the underside of the deck I just want to leave it unpainted and unstained.


The framing doesn't have to be painted or stained.


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## DIY_ing_Guy (Nov 19, 2010)

While pressure-treated is intended to protect primarily from insects, fungus, bacterial rot, exterior weather exposure and UV in sunlight will definitely result in checking and splintering of the surface. I'm going to be replacing my entire deck; it is PT but was never stained, and at 7 years old when we bought it the deck boards were badly damaged. Stain provides add'l protection that is definitely needed IMHO.

Guy


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## DIY_ing_Guy (Nov 19, 2010)

While pressure-treated is intended to protect primarily from insects, fungus, bacterial rot, exterior weather exposure and UV in sunlight will definitely result in checking and splintering of the surface. I'm going to be replacing my entire deck; it is PT but was never stained, and at 7 years old when we bought it the deck boards were badly damaged. Stain provides add'l protection that is definitely needed IMHO.

Guy


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## 95025 (Nov 14, 2010)

stanlam said:


> I'm very confused about this. 90% of the articles I read say pressure treated wood must be painted or stained. However, I see pressure treated wood on peoples fences, decks, and walkways that was never treated or painted. Does anybody know the truth?
> 
> I want to built a deck platform, but I don't want to paint or stain most of it. I only want to paint the wood that people can see on top of the deck. The framing and the underside of the deck I just want to leave it unpainted and unstained.


You should be (more or less) okay leaving the framing of the deck untreated. It will be mostly protected from the elements.

Keep in mind that even pressure treated lumber will eventually rot, if not top-coated regularly. However, if you keep your deck platform water-proofed, you'll go for many many years before your framing has any problems.


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## stanlam (Aug 25, 2009)

DIY_ing_Guy said:


> While pressure-treated is intended to protect primarily from insects, fungus, bacterial rot, exterior weather exposure and UV in sunlight will definitely result in checking and splintering of the surface. I'm going to be replacing my entire deck; it is PT but was never stained, and at 7 years old when we bought it the deck boards were badly damaged. Stain provides add'l protection that is definitely needed IMHO.
> 
> Guy


7 years is so short. what kind of wood are you going to replace the deck with?


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## Daniel Holzman (Mar 10, 2009)

A good way to protect the framing from rot is to cover the top surface of the PT framing with ice and water shield, or equivalent. I found this suggestion in Fine Woodworking, and applied the idea to my recently built deck.

Checking of framing lumber is not a serious problem. Clearly checking of the decking is a serious cosmetic issue, so if you are using PT for the deck, you need to think seriously about stain, paint, or similar protection. I built my deck using PT framing, ice and water shield over the PT framing, and Ipe decking (which I am coating with an Ipe sealant).


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## DIY_ing_Guy (Nov 19, 2010)

Can't say I've got a plan yet. Right now a basement remodel is taking my time, so the deck will have to last one more year (or at least until summer).

Guy


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## dpach (May 12, 2009)

I would definitely stain the top deck boards. As for the framing (joists, beams, etc, I built my new cedar deck last year and used PT for the framing. PT will eventually rot also, especially the tops of the joists where moisture can sit under the deck boards that sit on top of the joists.

I actually covered all framing with a blueskin product that is rubber/tar based under the blue coating that seals around the deck screws and prevents moisture from sitting under the deck boards and soaking into the top of the joists around screw holes.

It cost an extra $250 to do (blueskin and the extra adhesive glue which I applied first, let sit for 20 minutes and then applied the blueskin), but my joists will last for year. I dont' mind replacing a few deck boards over the years, but starting from scratch every 10 years of so is a pain.

Good luck.


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