can I use my fence for firewood?

July 21, 2008 1:53 PM

I have wooden fence that I would like to take down and burn in an indoor fireplace. is it safe?

I've asked many people, and gotten many answers. The fence is at least 11 years old, probably more. Do you think it was treated, and if it has, would that make it a bad idea? The fence is a 6 foot tall privacy fence, most probably cedar.

posted by rudy26 to home & garden (13 comments total)

What color is it? If it is mostly light gray it may very well not have been treated. However, you still won't know and burning lumber which has been varnished or sealed could release toxins, some of which will make their way into your home and your lungs. Also, if it is cedar it probably makes for too hot a fire and may have sap, both of which are bad for your chimney.
posted by caddis at 2:05 PM on July 21, 2008

Treated? Maybe. Bad idea, prolly. Just to be safe, I wouldn't burn it inside.
posted by MiggySawdust at 2:05 PM on July 21, 2008

If you don't know whether or not it has been treated, I would say that it's not worth the risk. There are too many nasty chemicals in fence preserver to stick it on a fire.
posted by Solomon at 2:06 PM on July 21, 2008

If there is any possibility at all that it was treated, don't chance it. If you google for "burning treated wood" you'll see why.
posted by amyms at 2:08 PM on July 21, 2008

The one part of the fence I would not burn is the posts... chances are those are treated and would have a lot of noxious chemicals.

Pictures would help, really.... we can't give you a clear answer unless we see the fence.
posted by tinkertown at 2:08 PM on July 21, 2008

Building materials are almost always treated with preservatives. If the fence is built of machine cut lumber I wouldnt risk it.
posted by elendil71 at 2:14 PM on July 21, 2008

Well, if you assume that it's been treated with creasote, and you google up the Material Safety Data Sheet (MSDS) you can learn that:

"Wood dust may form explosive mixture with air. Fire vapors and combustin products are irritants and toxic. Self-contained breathing apparatus (SCBA) and full protective clothing should be worn if material is involved in a fire."

and that

"Treated wood should not be burned in open fires or in stoves, fireplaces or residential boilers because toxic chemicals may be produced as part of the smoke and ashes. Treated wood from commercial or industrial use (e.g. construction sites) may be burned only in commercial or industrial incinerators or boilers in accordance with local, state and federal regulations."

That said, it struck me while reading that MSDS that it seemed to err substantially on the side of caution. Burning this wood in your fireplace certainly isn't going to kill you dead right then and there.
posted by Mike1024 at 2:18 PM on July 21, 2008

You don't know whether it was treated or even stained. I don't guesses are going to help you here. Dispose of it properly (even burning treated wood outside is harmful not only to you, but the environment).
posted by ssg at 2:37 PM on July 21, 2008

Seconding that you at the very least avoid burning the posts, since they're probably pressure-treated. You can generally tell pressure-treated lumber by its sort of greenish color when new, and by its surface, which looks as if it were stapled all over the piece of lumber. Some pressure-treating methods use arsenic, so you definitely don't want to burn that stuff. In general, I'd think burning the fence isn't such a good idea.
posted by LionIndex at 2:46 PM on July 21, 2008

Anything treated should not be burned. Additionally, pine wood should never be burnt indoors. Burning pine in your fireplace will coat the flue with resins that can ignite.
posted by Thorzdad at 2:56 PM on July 21, 2008

If it's cedar, is much less likely to be pressure-treated than pine, since the whole point of using cedar is that it's pretty rot resistant without any treatment. However, as cedar, it will not make a good fire. It will crackle and spit, and will produce a ton of smoke (meaning you have to keep the flue open all the way which sucks heat out of the room), and it will burn fast so you'll have to chuck more wood on the fire every five minutes. And of course it might still have residual stain or sealer chemicals in it. If it's in reasonable shape, take it down, pile it by the road, put up a big FREE sign, and someone will take it away very quickly, guaranteed (unless you're at the end of a dead-end road, I suppose).
posted by beagle at 3:00 PM on July 21, 2008 [1 favorite]

Also, cedar is awful for building up creosote residue in the chimney.
One or two peices, not a problem.
Burning a fence, might have yourself a chimney fire.
posted by Seamus at 3:27 PM on July 21, 2008

Even if it's cedar, and even if it's a "natural" grey, it could very easily have been stained or treated. I put up a cedar fence and coated it with what was supposed to be a UV protectant to slow down the grey (it didn't work). You couldn't tell looking at the fence that it was treated.
posted by PatoPata at 3:30 PM on July 21, 2008