Is pressure treated wood safe for indoor use?

Monday, March 15, 2010 by Dick Gauthier

ProWood Micro pressure-treated woodWe get this question a lot. The simple answer is pressure-treated lumber can be used in any interior application except cutting boards and countertops. Some have also asked, after they’ve found pressure treated lumber installed inside their homes, if there is any danger in having it indoors. The answer is no. There is no danger of either leaching or off-gassing. But these answers beg another question: Why would you use treated lumber indoors? The reason lumber is treated is to protect it from exterior elements that might cause rot, decay or termite infestation. In a protected environment there is no danger of rot or decay, unless the wood is exposed regularly to moisture, such as near a leaking pipe or window.

ProWood Borate treated lumberSome bathroom sub floor panel products are pressure treated as they may be exposed to moisture on a regular basis and some builders use borate-treated lumber, such as ProWood Borate, for sill plates in areas where termite infestation is common. In extreme areas of termite infestation, such as the US Gulf Coast and Hawaii, the whole structural shell may be constructed using ProWood Borate or other borate-treated lumber products. Other than those examples there would not be a need to use pressure treated lumber indoors.

Comments for Is pressure treated wood safe for indoor use?

Monday, June 6, 2011 by Wava Baker:
HI, I just read that you could use pressure treated wood indoors. we are replacing a camper floor and would like to use pressure treated as the subfloor.
so after reading this it should be ok.
Thanks
wava
Tuesday, June 7, 2011 by Dick Gauthier:
Wava: Yes, with the exception of eating surfaces, pressure treated lumber is safe for indoor use.
Wednesday, June 29, 2011 by James:
I salvaged dozens of pieces of treated lumber from the demolition of an outside barn, and I intend to use the pieces for basement shelving. Based on your report and other information I've found on-line, I believe this application will be appropriate and safe. Thanks!
Wednesday, June 29, 2011 by Dick Gauthier:
James: We agree. Thanks for your comment and good luck with your project.
Sunday, July 24, 2011 by JWReeves:
We have a very limited budget and have found treated 1 x 6 decking boards to be far less expensive than their untreated counterparts. Would the treated would, then, be safe to use as wood flooring itself (not subflooring)?
Thanks,
JWR
Monday, July 25, 2011 by Dick Gauthier:
JWR: The PT 1x6 would be safe, but maybe not the best choice for flooring. For reasons of aesthetics and performance you would be better off with a hardwood for interior flooring.
Saturday, September 10, 2011 by Melissa:
Is it okay to use pressure treated lumber as top decking, even with young children walking possibly barefoot on it?
Wednesday, September 14, 2011 by Dick Gauthier:
Melissa: Unequivocally, yes.
Tuesday, November 8, 2011 by Brandon:
We live in a very wet area and our house is a little over 60 years old. Since we have purchased our home we have had to lift the house and replace the floor joist, sill plate, rim joist, and the main beam with treated to avoid this issue of rot in the future. So all that to be considered my question is this, when the house was built they used the joist cavities as cold air returns for the furnace because the house sits on only a two block craw, is it safe to use treated lumber for cold air returns????? Off gassing in my furnace?
Tuesday, November 8, 2011 by Dick Gauthier:
Brandon: This is a question I never would have anticipated. I have to say it’s an interesting situation.

If you were using our ProWood Micro CA for this application
I’d have full confidence saying you’d have no worries. The MicroPro technology in ProWood Micro CA has been awarded the GREENGUARD Children & Schools Certification. GREENGUARD Children & Schools (SM) Certification program certifies products for low chemical emissions that are used in schools, offices and other sensitive environments.

If you bought and installed a product treated with a different formulation I’m afraid I can’t offer an opinion on it. That isn’t to say I don’t think it’s safe. But we just don’t have the research or the authority to say whether in this particular application it is. Thanks for the inquiry.
Saturday, December 17, 2011 by Egypt:
I plan on using a pressure treated 4x6 to create a design on my fireplace. Would you say it is safe to do so?

Thank you!
Tuesday, December 20, 2011 by Dick Gauthier:
Egypt: as treated lumber should not be burned I would caution against using it as a component of a fireplace.
Wednesday, January 18, 2012 by kathy:
just found out pressure treated wood (about 2 weeks old) was used in my kitchen for a door frame. Is that ok and how should I paint it?
thanks
Thursday, January 19, 2012 by Dick Gauthier:
Kathy: Leaving it unpainted will pose no danger to humans or pets (termites won’t care for it of course). This is more a question of aesthetics. If it looks fine unpainted, leave it.
Sunday, January 29, 2012 by Bobby:
I plan to finish a storage room in my basement. The previous owner has "DryLocked" the walls, which causes seeping rainwater to the floor, not much, but it's still present. I wanted to use BlueWood, but it's not available in my area. After reading this, I will select pressure treated lumber, hot dipped galvanized fasteners and green board/sheet rock. My question is, should I treat it with some kind of water repellant and does the pressure treated act the same as BlueWood?
Monday, January 30, 2012 by Dick Gauthier:
Bobby:
ProWood Micro would be far superior to BlueWood as regards long-term performance. No need to add water repellent as the MCA treatment is sufficient to protect the wood in the application you describe. Thanks for the inquiry and good luck with your project.

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