Old Timber Mystery: Creosote, or What?
The Woodweb detectives discuss old growth Heart Pine, younger Longleaf Pine, the hazard of creosote, and related topics. August 18, 2009
Question
I have run across some antique heart pine beams and lumber. Some are pressure treated and some have a black tar-like substance on them, much like a railroad tie. Is this creosote? All of it came out of an old mill. What are the uses for these type things? I know I can't use the pressure treated to make hardwood floors but what about the other beams?
Forum Responses
(Sawing and Drying Forum)
From contributor S:
I'm skeptical about antique heart pine beams being pressure treated. As far a creosote, take a chainsaw and cut off the end of a beam to expose fresh wood. If the creosote is on the surface and not soaked into the wood you could "skim" off the beam and get rid of the outer part and still have usable lumber.
From contributor B:
I was dumb enough to try to saw a pole treated with creosote. It was a nasty mess that stuck to my blade, stank, and made me nauseous. I don't know what you do with your sawdust but disposing of the dust with creosote in it is probably a hazardous chemical exercise. If you do decide to saw it I would use a respirator with more than dust filters on it.
From Gene Wengert, forum technical advisor:
It makes no sense to pressure treat (including pressure treating with creosote) true heart pine as this wood already has substantial natural decay resistance. Also, the wood is so impervious to liquids that pressure treating would not work, in general; it would have to be incised. Do you see incision marks? Further, a beam in a building would seldom be treated unless it is in a wet location, so there is no decay risk or hazard. What is more likely is that you are seeing the sap that has oozed out of the wood and then someone stained or painted the wood black (or maybe it just got dirty). Of course, the stain or paint could be related to creosote. If it is creosote, be extremely careful for your own health and the health of the environment.
From the original questioner:
I have never heard of pressure treated heart pine either, but the lumber the guy says is pressure treated definitely has that green tint to it. As for the other beams, they smell and feel exactly like a railroad tie. I will post pictures for everyone to get a better look as soon as I can take some. These beams are massive (16"x16"x25') and I would love to get my hands on them but if I can’t turn them into flooring I don't want to buy them.
From the original questioner:
Here is a picture of one of the beams I believe has creosote or something on it. I will post pictures of the pressure treated lumber as soon as I can get a picture. Let me know what you all think.
Click here for higher quality, full size image
From Gene Wengert, forum technical advisor:
It is my guess that the lumber is not heart pine. The beams look like they have pitch, but I do not see what I would call obvious creosote. Of course, an actual examination would be better than a picture. Many states have forest products specialists in the extension service that might help you ID the wood and any treatments. Check at your state university, or even at the county extension office, to find out who it is in your state.
From contributor S:
It looks like you've got some pretty tight growth rings there. I'd cut off the top 1" or so and see if that dark stain goes away. Don't breathe the dust - collect the dust and light it up the next time you have some brush to burn.
From contributor A:
The brown spot in the middle of the log near the pith is heart pine. The rest of the timber is just sap wood. You can see where the creosote soaked in. They would be great to use to build a barn or shed but would not make flooring out of them as the smell will never go away. They also make good bridge timbers.
From the original questioner:
I have a few questions. If it is creosote on the outside of the beams is the inside still okay to use if I cut two or three inches off of each side? To be honest I don't even know if the large beams are pine. They look and smell like it but is there any other way I would know for sure?
From contributor M:
What are the most distinctive characteristics of antique heart pine lumber - the smell or the tight rings? Or is it the turpentine substance that bleeds out when heated?
From Gene Wengert, forum technical advisor:
Heart pine (or antique heart pine) refers to wood from the longleaf pine tree (one of the four southern pines). The tree can survive for a couple hundred years and produces lots of resin meaning turpentine, etc. which are called naval stores). It is a key nesting site for the red cockaded wood pecker, so preserving old trees for this bird is actively done today. The trees of this species were almost totally harvested from the 1700’s up to WW II because it is such a useful wood. Ship masts, wide, decay resistant lumber, etc. It is highly desired for historic reproductions and remodeling, etc.
The sapwood in slow grown longleaf trees is only an inch or two wide. When cutting a square or rectangular timber, almost all sapwood would automatically be eliminated. Oftentimes, the rings are not spaced very far apart, as the tree was growing in a competitive forest. In your sample, you have substantial sapwood and the rings are not especially close, which is why I doubt that it is longleaf (antique heart pine).
From contributor S:
I've re-sawn thousands of bd/ft of reclaimed heart pine beams and have done some background research on why there is such a variation in quality in heart pine lumber. Here's the short version: The longleaf pine tree can live up to 500 years, any trees older than 200 years or so are technically "old growth" and those 100-125 years or older are "early old growth".
However you can find heart pine that was only 75-90 years old when cut. The sapwood usually wasn't used in the old buildings, the old time builders knew that the sapwood would be more subject to rot and bugs and any planks containing sapwood weren't used or the sapwood was cut off to make a smaller board.
From sawing up beams it seems like the nicer, straighter, logs were used for the very biggest beams, while the smaller, knotty top logs were used for roof decking.
So after all this, I'd say the wood you have is of medium to low quality, not great, but worth sawing up. The boards with creosote can be used, but I would probably steer clear of them. You'll have to decide after you discard some of the wood if it’s worth all the trouble to saw them up. If I had them, I'd put a few on the mill and see what the lumber actually looks like. Sometimes the quality will surprise you, sometimes not. I usually try to put the beams on the mill so I end up with some quarter/rift sawn boards.
From contributor R:
That doesn't look like heart pine (longleaf) and it definitely isn't old growth antique heart pine - too much sapwood and too few rpi. They do appear to be creosote treated. I wouldn't saw that stuff for any amount of money.
From contributor K:
Do you think it is pine or some other species? I think we all agree it is not old growth anything but it also does not have the smell of pine at all could it be something else?
From contributor M:
I agree but the smell is just not there. Is this common to look like pine, feel like pine, but not smell like pine, and still be pine?
From contributor R:
It may be fir, spruce or even hemlock. It may help if you said where it came from.
From contributor M:
It came out of a textile mill warehouse in Northeast Georgia.
From contributor R:
More than likely it's pine or hemlock.
From Gene Wengert, forum technical advisor:
If you send me a small piece (1/2" thick, 3" long and 3" wide), I can identify it - no cost in this case. However, with pine, we cannot separate it into specific species, just into a few groups.
From contributor K:
The beams he has sent pictures of other than the smell of creosote do not have any other distinctive smells like the pine we found at this location whether it is considered "antique heart pine" or just plain ole old pine we do not know. What other type of wood could it be? Is it softwood or possibly hardwood? What else did they use 50-100 years ago? This is coming out of a textile mill 's warehouse if that helps.
From contributor R:
It looks like pine just not longleaf (heart pine), especially not like old growth longleaf (antique heart pine). The first picture he posted looks a lot like red pond pine/pitch pine but it could be slash, loblolly, shortleaf or even Virginia.
From contributor M:
It was cut about the same as some of the antique heart pine, but does not have the same smell. Could it be a hardwood? I just feel it is something else due to the fact there is no pine smell whatsoever.
From contributor R:
It could be something else, but if you haven't cut any of it it may not have a pine smell. I don't know how you would be able to smell the pine scent if it is creosote treated anyway. Take a hand plane and shave a clean spot on the end and get a better look.
From contributor M:
I did take a cut through the middle and where the creosote stain stopped, I square cut it. Once the creosote was removed there was still no real smell in the center of the log. I have dealt with some old pine in the past and it always had a slight to strong pine or turpentine smell. This seems to have none whatsoever.
