Is there any reason a person shouldn't use pressure treated lumber when repairing the framing?
Outgassing. The chemicals used are released over time esp when heated.
I considered that but being encased by the interior paneling and exterior skin I wasn't sure that it would be a real threat. I'm working on a, "68" Fireball that is far younger than myself and was considering Tyvex wrap both inside and outside. Hummmmm ?
I might think of using plastic sheeting on the interior. I remeber the FEMA trailers and formaldihyde (SP). If you used plastic and sealed the edges and openings to the interior you would also need to ensure adequate ventilation of interior moisture. Have you thought about using cedar or redwood which are naturally resistant to rot and bugs?
That and the same reason it is not used when building a house - it just is not necessary.
PT wood is for exterior use only - fences, decks, etc...
Just seal the coach well and you're good.
Keep in mind that the pressure treated wood we all grew up with is no longer being made. It use to be impregnated with chromated copper arsenate (CCA). They key ingredient being "arsenic", and it would leach out or "outgass" just like Ad Addison stated.
After DEC 31, 2003, CCA products were banned. Today most pressure treated woods contain ammonia, copper and quat (ACQ). ACQ is actually pretty safe, and the manufactures say its safe to use indoors.
On my rig, I used it where water cannot be avoided. The entry step in my RV is ACQ, and the floor in my bathroom is also ACQ.
After all that technical garbage, I'll follow up by saying I don't think the new stuff is as good as the old stuff. I just threw away Landscaping timbers that had started to rot, and I'm not sure they were 8 or 9 years old. I remember as a kid pressure treated wood use to be advertised with a 30 year guarantee.
Thanks to all, guess I'll use redwood around the bottom.
I have used this treated lumber in the past. The new treatment process seems to endure just as good as the other banned chemicals of the past. Other options for longevity and water/rot resistance is cypress. The tree grows in the swamp and is very durable even to bugs that borough wood. Whats really weird is the PT lumber when dried out completely is lighter than a comparable grade of non PT lumber.