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Treated lumber?

PostPosted: Wed Sep 26, 2007 12:36 am
by Nosty
Hi Everyone. One question.

The trailer's parked in the back yard, the windows are in the hands of UPS headed my way, (thanks to EBAy and Lil Bear; the local camper dealers are extremely proud of their windows) :shock: , and a whole lot of other doo-dads and thingamabobs are cluttering my shed.

I was working on the final draft of my plans and I was wondering why I hadn't noticed anyone using treated plywood, or treated lumber in general, for the floors and underframes of their TTT's? I realize it's a little heavier and more expensive, but is there some other reason no one seems to be using it? Aside from it being toxic when it burns, unfortunately, should a teardrop catch fire with someone in it, noxious fumes are going to be the least of their worries.

I was just curious. I'm sure there must be a reason and I was wondering what it was.

Thanks for all the great information I've found on this forum.

Have a great day.

Brian

PostPosted: Wed Sep 26, 2007 12:46 am
by madjack
Brian, treated lumber can outgass arsenic and copper chromate and is best kept well away from the sleeping compartment...especially a small enclosed space such as in a Td...plus it is more expensive, is (usually) a cheaper grade of lumber and not generally considered to be worth the extra cost...
madjack 8)

PostPosted: Wed Sep 26, 2007 12:50 am
by Elumia
Wherever you cut it you need to treat it with something too.

Mark

PostPosted: Wed Sep 26, 2007 12:58 am
by doug hodder
Brian...lots of tears have been built since the late 30's and not used the treated lumber, they didn't have it then!...I'd avoid it...for reasons previously mentioned. You are so up close and personal with it all...not worth taking the chance, since you are in an enclosed box....and I'm not a "greenie" Besides...all the treated stuff I've ever worked with had a moisture content like 50%...liquid squished out of shooting a screw into it. Just say NO! Doug

Treated Lumber?

PostPosted: Wed Sep 26, 2007 1:09 am
by S. Heisley
Hi, Nosty:

I’m a newbie; but, here’s what I “think” I know:

From some newspaper articles, I read that until January, 2007, pressure treated wood could contain arsenic. The practice of allowing arsenic in the treating process was outlawed then. (As well as being a known poison, arsenic has been found to be carcinogenic, leaching from the wood into the surrounding areas.) Since the lumber companies are still providing pressure treated wood, I would assume that they have found a way to do so without using arsenic. I doubt the revised pressure treated wood’s longevity has had opportunity to survive the test of time yet.

Of course, the asphalt stuff used in treating trailer floors is very possibly carcinogenic, too; but, I doubt that stuff leaches. (Street asphalt is carcinogenic.) The green wood preservative suggested by Kuffel Creek? I have no idea about it. Is that the same stuff that is used on pressure treated wood?

Thanks for putting the question out there, Nosty. I am also very interested in the answers you get.

Sharon

Re: Treated Lumber?

PostPosted: Wed Sep 26, 2007 1:26 am
by doug hodder
S. Heisley wrote:Of course, the asphalt stuff used in treating trailer floors is very possibly carcinogenic, too;
Sharon


Sharon...I think the use of asphalt emulsion on the undercoat depends on where you are located environmentally and whether or not you think you need it. I know of lots of builders that don't use it, just a good oil based primer and paint, some have done latex...lots less hassle with the goo and clean up. I had a 49 Kit in 1980...just paint, probably oil based, on the underside and it was still hanging in there 31 years down the road. If you are concerned with the personal environmental issues, decide what is best for you. Just my opinion. Doug

PostPosted: Wed Sep 26, 2007 5:32 am
by jay
to accept the pressure treating process, certain woods must be used. the wood is usually new growth and porus (i.e. pine). this renders the final product unstable. ever leave a piece of PT lumber in the sun for a couple of hours?

several natural choices would be better- oak immediately comes to mind. trim your weight by reducing the cross section to the minimum size which will get the job done.

coating? good is you can deal with the goopy material. anyone try 'pick-up' bed liner available as DIY? or a penetrating clear finish and renew annually.

PostPosted: Wed Sep 26, 2007 9:01 am
by Alphacarina
If you're going to seal it with something (undercoating, epoxy, paint, etc) then it should be safe to use . . . . but if you're going to seal everything, why do you need treated wood anyway?

Personally, I avoid it unless I'm building something which specifically needs the protection it provides - Like something being in contact with the ground, or something I can't paint . . . treated lumber doesn't really like to be painted anyway since it bleeds though

Don

PostPosted: Wed Sep 26, 2007 9:50 am
by bobhenry
First of all all treated wood is Southern yellow pine. Approx 40% stronger than the spf most of us are buying at the box stores.

CCA is no more ! Replaced by Copper Naphthene for above ground uses such as exterior trim and lumber without ground contact

CAB is a Copper Azole based treatment for ground contact

ACQ is a copper Quat process with micronized copper powder.

BORATE SALT TREATER is the friendliest but it will eat up non galvanized fastners so galvanized nails and screws or stainless are best

I paid 6.00 a sheet extra for 3/4 treated plywood on my 24 x 8 mini barn delivery trailer 4 years ago. It sets out in the rain and snow 24 - 7 and I see no ply seperation and no deteriation beyond discoloration.

I see a definate benefit to utilizing the treated lumber and yes you can paint it and no it shouldn't squirt water if dried properly after treatment.

and best of all you have no chance of dying of arsnic poisoning

Thank you.

PostPosted: Wed Sep 26, 2007 9:59 am
by Nosty
Thank you all for your input. I should have considered the moisture content. I built a raised deck around my pool last summer and, as you said Doug, everytime I'd drive a screw through it, it gushed; not to mention the 2X2 slats I had to replace once they spent some time in the sun. I was, however, under the impression that they stopped using arsenic as a treatment. I may be wrong.

I was just looking for an alternative to the roofing epoxy. I replaced the hip roof on my house in the spring and after I sealed the vents and seems with it, I looked like a speckled pup for a week. That stuff just doesn't come off. I guess that's why everyone uses it.

Again my many thanks for all your generous and extremely helpful assistance. Should you see a rather large, spotted man in town next week, just nod knowingly and smile; off to Home Depot. ;)

Have a great day.

Brian

PostPosted: Wed Sep 26, 2007 10:23 am
by Clancy Courtney
Brian, Since you are in SC, there is a saw mill at Alcolu that handles cypress. Its located at the intersection of I-95 and US 301. If you're interested I can get phone #.
Clancy

PostPosted: Wed Sep 26, 2007 10:43 am
by S. Heisley
What about using CPES from Dr. Rot? (See www.mikenchell.com/weekender/skinning/html and www.rotdoctor.com/house/Hsealer.html) Has anybody done that yet? Would that work?

PostPosted: Wed Sep 26, 2007 11:00 am
by madjack
I don't use the goop on the bottom but rather MinWax ClearShield...will probably use RAKA Epoxy on the new one...the use of "googp' became popularized because Kevin at Kuffel Creek recommended it in his plans for the Cubby build...mainly because it is cheap and effective...any thing that seals the wood should work just fine and yes most treated lumber producers recommend that you allow their product to "weather" for a year before attempting to apply any sort of finish to it............
madjack 8)