I just finished a concrete retaining wall for a neighbor and she wanted to leave the 2 by 12 pressure treated board in the wall. Well today when I was cleaning up I saw she had planted veggies and rasberrys right up to the wood. I told her that the board was full of arsenic but she said because the wood was not touching the ground it was fine. My question is don't you think the rains and watering would wash the poison into the soil? Gosh I don't want them to get sick! What do you guys think?......Kirk

-- Anonymous, June 30, 2001

Answers

It will take a long time for the arsenic to leach out enough to be a problem if its not actually in ground contact. Even if it is in ground contact it still takes years. I used PT lumber for my raised beds for years before anybody knew it might cause a problem.

The problem is that arsenic is a cumulative poison. One or two doses in the range we're talking about (leaking in to the soil) isn't going to be a problem, its year after year after year as it accumulates in your system.

I don't use PT lumber anymore and haven't for almost 20 years, and you've warned her, I don't think there's anything else you CAN do except comfort yourself that the risk under the circumstances (if it isn't in direct ground contact) is likely to be small.

-- Anonymous, June 30, 2001

Given that only minute amounts of arsenic are enough to interfere with the body's defense against formation of some cancers, I would take it seriously. Tests here in W.Va. have shown that, in garden beds contained by pressure-treated lumber, arsenic does leach into the soil and is taken up by vegetables. Studies elsewhere have shown that it also accumulates under things built aboveground and exposed to rain. Now, there's a lot we don't know about this complex picture, but I would stay away from the stuff as much as possible. I think it would be banned today but for the influence of industry. There are alternatives.

-- Anonymous, June 30, 2001

Sam, I wouldn't use it in a garden setting - in fact I've said I don't. Even so it takes years for it to leach enough into the soil to become a problem, and that's IF its in direct ground contact. If its not, the rate of leaching is significantly reduced.

But I DID use it extensively in building my pole frame house. I'm just as glad we've got it, because otherwise I'd be looking at replacing those poles in 10 to 20 years. Everything within 3 feet of the ground is PT, including the subfloor plywood. This protects from rot and insect damage as well. Termites might TRY to eat my floor but they'll die.

The only alternatives I've seen are worse either in what they leach into the soil, or in the manufacturing process itself, or they are not as strong structurally.

What alternatives to PT do you suggest for construction applications that require ground contact? Maybe there's something new out there I don't know about.

-- Anonymous, June 30, 2001

Check this out: Arsenic-Free Pressure-Treated Wood WARNING: The site has a vocal greeting after it finishes loading. Startled me, because they didn't used to have it!

Here's a short blurb from their front page:

Welcome To Northern Crossarm

The home of Arsenic-Free Pressure-Treated Wood

For more than a decade, arsenic-and chromium-free PreserveŽ treated wood has been used in some of the world's most environmentally sensitive locations. From the pristine environments of national parks in Australia, North America, Europe and Japan, to neighborhood playgrounds and backyards like yours, Preserve treated wood has been used around the globe to provide a durable building product for outdoor projects where environmental values and product safety are priorities.

Northern Crossarm Co. Inc. is a recognized leader in the Mid West in the manufactured products of Arsenic-Free Pressure-Treated Wood using PreserveŽ treatment.

-- Anonymous, June 30, 2001

Should have mentioned -- they use copper and 'quats' for preservation. I don't think I'd use the stuff for food production beds, and the chemically sensitive might have a problem with handling it too.

-- Anonymous, June 30, 2001

Hey Joy! how did you do that! How did you make your words green. I can't do that, I don't have that option, I do on my e-mail but not here.Hm, is there a way that I can do that? Oh and hey, is there a way to put a spell check on this thing? just me Tren

-- Anonymous, June 30, 2001

Trendle, its HTML programming.  If you are a Netscape user you can use Netscape Composer to build your pages without having to know any HTML, just use the toolbar items to control font attributes such as size and color.  Type it into composer as you want it, then save the file.  Then use EDIT - HTML from the menu and it will open a text editor with all the HTML commands laid out for you.  Just copy and paste.

There'll be some HTML you don't really need, if you want you can type START at the beginning of your text when you are first typing it up and then END at the end, then just select everything between when you open up the text file.

If you want to do it by hand the command to change the color of the text is:

<font color="#FF0000">type the text you want to come out colored in here</font>

Color codes are:
Red = #FF0000
Green=#006600
Yellow=#FFFF00
Blue=#000099
Orange=#FF6600
Purple=#CC33CC
Black=#000000

The first two digits are a color code for the RED component, the 2nd two are for the GREEN component, and the last two are for the BLUE component, giving you an RGB code for color value.  There are slews of different shades but those are some basic ones.

Hope that helps.
 

-- Anonymous, June 30, 2001

I went and looked over the site. It's copper based, I don't know what "quats" are nor do they explain. Copper is in and of itself pretty toxic, but in the absence of soil testing data I can't say if its any better or worse than normal PT wood as far as leaching into the soil and accumulating there.

You can only buy it in 6 states, mine isn't one of them.

I can't find any sign that this stuff is useful for structural components, like main support poles. Everything seems to be about decks and gazebos and stuff like that.

They also don't tell you what the "limited lifetime warranty" is. For PT wood its 40 years, and I've never heard of it failing. I have seen some decks and porches that were made partially out of PT and partially out of untreated lumber, and after only 3 years all of the non treated lumber in ground contact was punky and rotten, and the decking that was not PT (had been painted but was untreated) was beginning to dry rot, even though some of it was almost 4' from ground level.

Somewhere on the web there's a composite wood/plastic substance meant for decks and the like that can be sawn and nailed like regular wood. I looked into that at one time and though it was warranted for some reasonably long period of time, it was also of limited distribution and was EXTREMELY expensive to boot. It wasn't strong enough to use for any structural component (like a beam or post) either. Also, I talked to some people who used it and they said it tended to splinter in big long sharp shards kind of like what you can see with fiberglass sometimes.

Sometimes I think I should have gone for cement posts and just built conventionally framed on top of them.

-- Anonymous, June 30, 2001

Locust lasts for 20-30 years as used for fence posts, no dipping or treating required, it comes as black locust and sweet locust, both work the same. Around here, they go for 1.50 to 2.00 dollars a piece, cheaper than T posts!!!

Catalpa also lasts for more than 20 years, these hardwoods are what are forefathers used for ground and subground contact for generations, and outlast PTW by double the years!!!

-- Anonymous, June 30, 2001

Outlasts PT by double the years? Not even black locust posts will last 80 years. I don't know, maybe old growth redwood might - but have you priced redwood lately? EEEEEEP!

Unfortunately our forests have been so badly overharvested that high quality lumber is awful hard to come by, and extremely expensive. The stuff I am paying high prices for as #2 grade lumber would have been on the discard pile when I was a kid. I used to go to the lumber yard with my dad and its a whole 'nother ball of wax now.

I don't know what "sweet" locust is but honey locust posts will rot in just 2 or 3 years, sometimes less. Black locust is good but you can't hardly find it at all around here. I have a good sized black locust tree in my field (when I say good sized I mean its 15 or 20 years old, not really all that old for a tree). The neighbor was walking the field with me and when he saw it he said, "Well you're going to have to cut that out"

I hate to think what he would have said if I'd told him I'm planning on planting a bunch more of them. And Osage Orange, as well.

Sure wish I could get black locust posts for $1.50 to $2 apiece. Are those 4" or better posts? Where are you, maybe it'd be worth my while to drive down and get some! 4" PT posts 8' long cost around $6 around here. And I have fence to put up soon. As soon as I can get the house finished enough to move into.

-- Anonymous, June 30, 2001

Sojourner, we've all used PT wood in the past. Now we know better. If I had a house that incorporated PT wood, I would cover it, live with it, and not lose any sleep over it. But if I were planning to build, I would look at safer alternatives, such as copper & borax treatments or black locust. Incidentally, some fellow at Cornell is looking into a variety of black locust known as shipmast locust as an alternative to PT lumber - I don't know much about that yet, but sounds interesting. Friends of mine were in touch with him, and are now planning to plant this as a cash crop.

-- Anonymous, July 01, 2001

Sam sez "we've all used PT wood in the past. Now we know better."

Oh "we" do, do "we"? LOL!

Hate to disillusion you, Sam, but I CHOSE to use PT wood to construct my house because it is the best most economical material available to me (that won't rot or get eaten by termites).

I did check in to "alternatives" and none suited the purpose. Either they weren't locally available or were available only at great cost, or they were worse than "regular" PT, or the "alternative" wasn't available as structural components (such as post and main support beams) but only in components suitable for light duty applications such as decking.

Every alternative listed here suffers from one or more of the above drawbacks. Yeah, look for alternatives and use 'em if you can find 'em and afford 'em. But in the meantime I will continue to use PT wood. For example in the barn I'll be building this spring, and in the deck I hope to build this fall (if I get the house done).

If I can't locate black locust posts (which is my preference, certainly) then my fence will go up with 4" PT posts. I'd like to have black locust but there isn't much of it on my land, nor on surrounding farms because people have been cutting it (and hedgeapple) out for years as "trash" trees.

I'll also say this, outside of a garden application where the lumber is constantly exposed to rain and weathering, the amount of arsenic leached out of CCA treated wood is very low. The studies that showed the worst results in that regard were for wood with large surface areas exposed to acid rain - eg in urban and some suburban settings.

Even the posts on the perimeter of my house are not exposed to that sort of weathering or moisture, plus I seal them every year with a water repellant stain. Leaching is not going to be much of a problem under those circumstances.

I'm VERY interested in the shipmast locust, and have been for several years - but I can't find nursery stock for it. No one I know can find nursery stock for it, and that being the case it pretty much puts paid to the idea of using it for posts for my house. You can't find nursery stock for it because outside of a few research facilities no one seems to be growing it.

If your friends have located a source for nursery stock for shipmast locust I and several people I know would be EXTREMELY interested to know their source. We'd love to grow the stuff, and not necessarily just as a "cash crop". So if you've got a source for it, please please please please PLEASE post it. You'd be helping out a lot of people.

-- Anonymous, July 02, 2001

Well just to be sure I asked the lumberyard and I bought the arsenic wood (boo). Went back to the site and took down the boards above The veggies and left a note why. Went back later and the boards were back up!!!! Soooo I told her I would replace the boards and put up cedar (my cost). Her reply was please get lost!!! I tried. Thank you guys for your posts....Kirk

-- Anonymous, July 02, 2001