My family always hit the construction dumpsters. You can get a lot of decent pine lumber that gets tossed because it was cut wrong or stained with mud/ptty/etc. They throw a lot out because time is mor valuable to them then the wood. Even short end peices are useful for burning or turning into charcoal. Pretty rare that you get decent lengths for building though. Usually 6 feet and below are fairly common, with the rare 7-10 foot boards, and nigh unheard of 11+. And the builders are usually happy about it too, since they pay to have it emptied so everything you take is a bit less they have to pay, and no skin off their nose.
We have built a number of animal houses and even a few sheds around our land with the salvaged wood. Saved us a lot of money.
Dumpsters in front of new construction are my favorite. Lots of good pine studs, OSB, and other stuff. I built a whole workbench (with a spot for table saw and storage) out of materials I pulled from dumpsters on the street when they were building a new subdivision behind me. Some of my favorite picks were unopened bundles of shingles (heavy!) that I will use for a shed some day, a bunch of brand-new pex tubing, and an entire case of caulk.
Be careful if it’s been sitting in the sun. Lived in a building that had its hot water recirc lines fail one after the next like 5y after construction and I suspect that was why.
Note that not all dumpsters on a construction site are trash. The best example is metal, where a full dumpster brings significant money instead of costing to dispose of. When I was working in a construction company, on a regular basis some dudes came along "offering" to empty the metal dumpster for free.
So it's always better to ask first, otherwise it's technically stealing.
This is textbook safe that is lacking in street smarts.
You can't ask because then you're pushing the responsibility of you being there onto someone else. They don't want some ambulance chasing lawyer to come bitching at them if you get hurt so they have to say no. But if you're discreet can just pretend that you're trespassing.
So just don't ask and know what is or isn't fair game.
Additionally, scrap of the mixed random stuff variety that is worth picking through is cents a pound. They won't care if you're not taking serious volume.
We usually asked with only a few turning us down, though we are fairly rural/small town so the builders we interacted with may not have been burned by people that are sue happy or maybe are just smaller and didn't consider that legal aspect.
I'd be careful with this advice. First of all you don't know what else has been put into the dumpster. There could be toxic or hazardous materials. Especially if it's a renovation project.
Secondly, be careful with the wood if you don't know precisely what it is. For instance, making charcoal (or even burning) pressure treated wood is a horrible idea.
Generally, there _shouldn't_ be anything toxic in construction dumpsters. Not a lot of home construction deals with anything highly toxic anyway. Plus, if the disposal company finds something in there that shouldn't be there, they will refuse to take it, or levy a fine, or won't work with that contractor anymore.
Conversely, some randos see an open dumpster and think its a great place to chuck their old car batteries and whatnot.
Pressure treated woods scraps are generally thrown in dumpsters and they are toxic if burned. You never burn pressure treated wood.
You just never know though. For instance, it could be thought that there isn't any asbestos in the home being renovated. But maybe there were a couple pieces of drywall or pipe insulation that happened to have asbestos and it wasn't noticed. It happens.
There is also a very good chance that there's lead dust and chips from old paint or pipes that's being thrown in as well. Probably don't want to make charcoal or anything out of that or any new SPF/Doug tossed in there that maybe got some of it on it you don't notice.
Good point. Never ran into anything problematic myself, but we are fairly rural so construction is usually houses with occasional apartments. But definitely be wary of other stuff that may be in with the wood.
As for pressure treated wood, it is pretty obvious what has been treated and what has not, at least in my experience. Not sure if it's the process, or if they intentionally dye it, but treated wood has a strong green tint, though could probably have other colors too depending on the treatment method. But fresh untreated pine has a pretty obvious color.
The old CCA treated stuff got the green from the copper in it. It's hard to tell if the A (arsenic compound) is still in there if it's weathered. Not a good idea to burn scraps from demolished old outdoor stuff.
We have built a number of animal houses and even a few sheds around our land with the salvaged wood. Saved us a lot of money.