# How to finish pressure-treated wood used in bathroom sink installation **URL:** \ **Category:** Factual Questions\ **Created:** [November 21, 2011, 3:25pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648 "2011-11-21T15:25:33Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![emmaliminal](https://avatars.discourse-cdn.com/v4/letter/e/7bcc69/32.png) [@emmaliminal](https://boards.straightdope.com/u/emmaliminal)\ **Post date:** [November 21, 2011, 3:25pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/1 "2011-11-21T15:25:33Z")
Not sure if this belongs in IMHO or GQ, but I’m looking for factual suggestions and hoping for logical explanations about the relative merits of whatever our options are. My husband just took out our old bathroom sink, which was freakin’ huge with a cabinet base, and installed a much smaller one with a pedestal base. He got it from the Habitat for Humanity ReStore store. This needed to be a quick and cheap installation, and it was. (With all the extra room, we can now reach the tub to bathe our fast-growing toddler in it instead of the kitchen sink.) He used pieces of pressure-treated wood in certain key spots: first, between the sink and the wall, which is mostly ceramic tile in terrible shape but that we can’t do anything about right now. There is a small piece of old wood there that the old sink was attached to, flush in among the chewed-up tiles, attached to something solid in the wall. Husband attached larger piece of PT wood to that, and sink to _that_. Second, the plumbing wouldn’t all line up properly unless he put a substantial shim under the pedestal - another piece of PT wood there. Everything is nice and stable and properly pitched and he even routed the wood edges nicely before he bolted stuff together – but it is still naked PT wood, with no sealant or anything. I’d like to do whatever we’re going to do ASAP, before there gets to be toothpaste spit splatters on the top piece and pee splashes on the pedestal base piece (it is next to the toilet, of course). What should we use to finish and detail the wood? My first thought is “spar varnish” but I have not had good results with that stuff in the past, even applied exactly per directions. And shouldn’t we do something like caulk the gaps where wood meets tile? Aesthetically, I think a clear finish would be nice – PT wood is a shade of green that happens to go well with the color scheme in there. It maybe looks weird to have wood in those spots, but the wall tile, and incidentally the late 60s linoleum floor, already disqualify us from \*House Beautiful \*showcases. _Eclectic Yankee Decor Ideas,_ though – we’re a shoe-in. ---
**Author:** ![Bag\_of\_Mostly\_Water](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bag_of_mostly_water/32/1029_2.png) [@Bag\_of\_Mostly\_Water](https://boards.straightdope.com/u/Bag_of_Mostly_Water)\ **Post date:** [November 21, 2011, 3:34pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/2 "2011-11-21T15:34:46Z")
Most pressure treated wood contains high levels of arsenic and is not suitable for indoor use, especially with a toddler in the house. The only safe option is to re-do everything and use something besides PT wood. ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [November 21, 2011, 3:38pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/3 "2011-11-21T15:38:15Z")
I would paint it with a high-gloss paint, and then caulk the edges, like you stated. Pressure treated wood looks fine outside for a deck, but not in your bathroom. I would find it tacky, myself. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [November 21, 2011, 3:44pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/4 "2011-11-21T15:44:55Z")
For protecting interior wood that will be subjected to the off splash I would recommend tung oil. Ideally you need to give it a good few coats, letting each one dry for a day or so. Water will then just bead off it. ---
**Author:** ![Baracus](https://avatars.discourse-cdn.com/v4/letter/b/2bfe46/32.png) [@Baracus](https://boards.straightdope.com/u/Baracus)\ **Post date:** [November 21, 2011, 3:45pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/5 "2011-11-21T15:45:06Z")
Perhaps I am misinformed, but I believe that at least for outdoor applications fresh pressure treated needs to be allowed to dry for months before applying a finish. I think there is some pricey PT out there that is kiln-dried again after treating where this isn’t applicable. I agree with **Bag of Mostly Water**. Remove the pressure treated and replace it with something else. If you seal it well, there is no reason why it needs to be pressure treated. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [November 21, 2011, 3:59pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/6 "2011-11-21T15:59:44Z")
They haven’t sold arsenic treated wood, CCA for residential use since 2003. EPA banned it for residential sales. > [@](#): > > Effective December 31, 2003, no wood treater or manufacturer may treat wood with CCA for residential uses, with certain exceptions. [http://www.epa.gov/oppad001/reregistration/cca/](http://www.epa.gov/oppad001/reregistration/cca/) The current treated material is ACQ and uses copper. Home Depot sells a special type called Weathershield. It’s still copper based but doesn’t corrode metal as badly as ACQ. I just finished rebuilding a 16x16 ft deck with the premium grade pressure treated from Home Depot. [http://www.homedepot.com/webapp/wcs/stores/servlet/ContentView?pn=WeatherShield&langId=-1&storeId=10051&catalogId=10053](http://www.homedepot.com/webapp/wcs/stores/servlet/ContentView?pn=WeatherShield&langId=-1&storeId=10051&catalogId=10053) > [@Bag\_of\_Mostly\_Water](#): > > Most pressure treated wood contains high levels of arsenic and is not suitable for indoor use, especially with a toddler in the house. The only safe option is to re-do everything and use something besides PT wood. OP’s question, I’d prime your wood with a high quality primer. Then paint with enamel paint. Benjamin Moore has a primer called Fresh Start that is very good. I like their enamel paints too. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [November 21, 2011, 4:09pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/7 "2011-11-21T16:09:51Z")
treated wood will change color. i would prime and paint it with a paint that will take water exposure. ---
**Author:** ![emmaliminal](https://avatars.discourse-cdn.com/v4/letter/e/7bcc69/32.png) [@emmaliminal](https://boards.straightdope.com/u/emmaliminal)\ **Post date:** [November 21, 2011, 4:56pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/8 "2011-11-21T16:56:34Z")
All those of you recommending primer and paint: Any actual product names to recommend? > [@aceplace57](#): > > …The current treated material is ACQ and uses copper… Yep. This stuff is ACQ, which is rated for indoor or outdoor use for everything except food prep surfaces. Toddler is safe. [http://www.ufpi.com/product/ptlumber/ptfaq.htm#5](http://www.ufpi.com/product/ptlumber/ptfaq.htm#5) [QUOTE=Universal Forest Products, producers of “ProWood” brand ACQ-treated wood] _Can ProWood ACQ treated wood be used indoors?_ ProWood ACQ Treated wood may be used indoors for any application except cutting boards and countertops. _Why can treated wood be used for a picnic table and not a countertop?_ Simply because picnic tables are primarily used for serving prepared food while a kitchen countertop is used primarily as a cutting surface for raw food. [/QUOTE] I’m a bit surprised this isn’t more common knowledge, that arsenic-treated wood has been off the market for a while now. My husband was overjoyed when this was new news, as he has had a lot of arsenicky splinters from landscaping work over the years. They were NASTY mofos. **Baracus** ’s point is a good one, though – I know the wood isn’t just off the lot, but I’m not sure how long it’s been “garage dried”. Probably at least six months, maybe a year and a half or more. Husband might remember. **Leaffan** , probably tacky, check. However, as noted previously, it fits the overarching [decor theme](http://en.wikipedia.org/wiki/Yankee#In_the_United_States) perfectly. [QUOTE=Wikipedia] Traditionally, Yankee was most often used to refer to a New Englander descended from the original settlers of the region (thus often suggesting Puritanism and **thrifty values** ). [/QUOTE] (Bolding mine. Also, we have a toddler.) ---
**Author:** ![purplehorseshoe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/purplehorseshoe/32/2996_2.png) [@purplehorseshoe](https://boards.straightdope.com/u/purplehorseshoe)\ **Post date:** [November 21, 2011, 5:07pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/9 "2011-11-21T17:07:23Z")
For a clear finish, I guess I’d go with polyurethane. You can either paint it on, or spray it. I’m no handy(wo)man, though, so I defer to anyone with more experience (read: any experience.) ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [November 21, 2011, 5:22pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/10 "2011-11-21T17:22:32Z")
I’m not sure if knots in pressure treated pine will bleed through paint or not. To be safe, I’d use a shellac based primer. I’ve used it before to seal old knotty pine paneling. I never saw any knots bleed through my paint job. home depot has this primer. [http://www.rustoleum.com/CBGProduct.asp?pid=216](http://www.rustoleum.com/CBGProduct.asp?pid=216) you’ll need to sand lightly with medium grade paper before painting. For bathrooms semi-gloss enamel is very water resistant and easily cleanable. Get a good brand like Sherwin Williams or Benjamin Moore. ---
**Author:** ![thatguyjeff](https://avatars.discourse-cdn.com/v4/letter/t/6de8d8/32.png) [@thatguyjeff](https://boards.straightdope.com/u/thatguyjeff)\ **Post date:** [November 21, 2011, 5:40pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/11 "2011-11-21T17:40:00Z")
> [@Bag\_of\_Mostly\_Water](#): > > Most pressure treated wood contains high levels of arsenic and is not suitable for indoor use, especially with a toddler in the house. The only safe option is to re-do everything and use something besides PT wood. This. Never use PT wood indoors. ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [November 21, 2011, 5:44pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/12 "2011-11-21T17:44:17Z")
> [@thatguyjeff](#): > > This. Never use PT wood indoors. Read the post three above yours. It’s fine to use indoors. ---
**Author:** ![corkboard](https://avatars.discourse-cdn.com/v4/letter/c/e9bcb4/32.png) [@corkboard](https://boards.straightdope.com/u/corkboard)\ **Post date:** [November 21, 2011, 7:16pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/13 "2011-11-21T19:16:47Z")
Did you specifically use PT wood because of its location in a wet/damp environment, or because it was handy? Just curious. Either way, if it were my bathroom I’d just trim it out with something non-PT, and prime/paint that with basic interior enamel. Or a few coats of a nice poly finish. Either one will protect the trim and PT from moisture and/or water damage, up to a point. I’ve never actually heard of using PT in a bathroom; usually it is used in an interior application such as a baseplate for a stud wall in the basement, since it will be against a porous cement surface. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [November 21, 2011, 7:26pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/14 "2011-11-21T19:26:34Z")
PT wood is generally pretty rough since it’s mainly for decks and framing in wet areas. But with some vigorous sanding PT will paint up nicely. One trick, Sherwin Williams sells thin sanding sponges with medium or fine paper glued to one side. Do yourself a favor and pick up a few. They are less than a buck each. A painter gave me this tip one time when he saw me massaging a cramp out of my hand. I always cramp up bad using plain sandpaper. Those sponges give you some to grip and they are very flexible. Great for edges, and irregular surfaces. Don’t get those thick, stiff sponge sanding blocks Home Depot sells. They are useless. IMHO they are so darn stiff. Sherwin Williams is the only supplier I know that still sells those thin, brown sponge pads. ---
**Author:** ![emmaliminal](https://avatars.discourse-cdn.com/v4/letter/e/7bcc69/32.png) [@emmaliminal](https://boards.straightdope.com/u/emmaliminal)\ **Post date:** [November 21, 2011, 7:30pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/15 "2011-11-21T19:30:57Z")
> [@corkboard](#): > > Did you specifically use PT wood because of its location in a wet/damp environment, or because it was handy? Just curious. I don’t know for sure – my guess is it was handy and close to the right size, with water resistance considered a plus. We own a venerable woodshop shed (previous house owners outfitted it and left it intact) and I’m never sure what all in there has been there since Watergate and what’s leftovers from a recent project. I do know this was ACQ, though, and not the old arsenic crap, because one scrap still had the lumberyard tag stapled on the end. If I had to bet a shiny nickle, I’d say these particular bits of wood are most likely left over from the Great Flowerbed Project of May '11 (which, incidentally, never got any flowers put in it, but did spontaneously generate a fine crop of cherry tomatoes and gigantic butternut squash, volunteered by undercooked kitchen compost). ---
**Author:** ![Implicit](https://avatars.discourse-cdn.com/v4/letter/i/6a8cbe/32.png) [@Implicit](https://boards.straightdope.com/u/Implicit)\ **Post date:** [November 21, 2011, 8:04pm UTC](https://boards.straightdope.com/t/how-to-finish-pressure-treated-wood-used-in-bathroom-sink-installation/603648/16 "2011-11-21T20:04:14Z")
> [@purplehorseshoe](#): > > For a clear finish, I guess I’d go with polyurethane. You can either paint it on, or spray it. I’m no handy(wo)man, though, so I defer to anyone with more experience (read: any experience.) [Wipe on poly](http://www.minwax.com/wood-products/interior-clear-protective-finishes/minwax-wipeon-poly) is very easy to use.