Joist for new sunroom, treated or not?

[Snobdds]

I have to agree on the horrible quality of pressure treated wood. I only buy it when I can use it that day and get it fastened down. I redecked a trailer with pressure treated a few years ago and had a 16 penny nail space between each board. I now have some places where there is an inch gap.

Next time I am going to use regular pine and just put a couple heavy coats of 50/50 oil and diesel. The original deck lasted 15 years and was just plain old pine, I don't know why I messed with what worked.

 

[MacLawn]

I'm a believer in treated wood, living in southeast where if you stand still long enough, something will try to eat you. Woodlice are nasty little devils. But, you need to let treated wood cure a long time before using. At least a month would be good. I've used it still wet with no problems, but didn't have time on that job for siting time.

 

[/pine]

If you shop around in most major markets treated lumber that has been kiln dried AFTER it has been treated is available....it is as stable as any KD lumber...

one caveat about the chemicals now widely used in treated lumber...is use coated, stainless or hot dipped galv. fasteners...the chemicals will eat up common nails in short order...

FWIW...most building codes recommend a minimum of 18" of free space between earth and the bottoms of (untreated) floor joists...