Preserving logs

[PowerNewbie]

We want to use various sized oak and pine logs in our landscaping, and maybe to build one or two bridges over small seasonal streams. It seems that they only last a couple of years before decomposing, especially when in wet ground contact.

Is there a good treatment we can do to make them last longer? I've heard that borax can be used on housing lumber, will it work in this situation?

[beenthere]

Buying pressure treated wood will probably be the most cost-efficient for you. Otherwise, use the oak if available, as it will last the longer than the pine.
There is no treatment that is available, including the borates, for 'home' treatment (too bad Penta isn't still available) that I am aware of, and don't think treating is an option.

The bridge, where not in ground contact, may be a bit better for you, but buying treated (if you can't get redwood heart   ) is best.

[rebocardo]

If you want to use them, then I would set them on cement pads and strip the bark off them if you want them to last longer.

Even p.t. 4x4s get mushy when on wet ground and fall apart, though technically they do not rot.

[WH_Conley]

If uou do use the oak make it white, it will outlast the others, of the species we have here anyway.

[SwampDonkey]

Yes, I also recomemnd white oak and also under cement blocking to keep the wood out of the wet muck. Unless your in a  wet climate the white oak will last quite awhile. Also, white ash is quite resilient, even butternut. Butternut may not be strong enough though for long term. They use untreated white oak at the water wheel of the sawmill at the King's Landing Historical settlement. This past year they had to import it from Pa, since it doesn't grow here, other than very scattered burr oak. These had to be big timbers.

I was trying to search for the thread with the large white oak timber used in the water wheel at King's Landing. No success :(

[Gilman]

Sounds like the beam Jim sawed up.  

[Furby]

The thing to remember with P.T. wood is there are different grades. Most P.T. wood is NOT rated for ground contact. Look at the lable on the end of the board, it should say.
There are even some P.T. wood that don't meet the standards of P.T., but some people still buy it thinking it's OK and not knowing the difference.
That explains why some P,T, wood don't last to long.

[Quartlow]

Locust, there are some post's around the farm that have been in the ground 100 years or so and they are still solid.

Keep in mind that when that PT lumber rotts away all the chemicals are leeching into your ground. Do    you really want to put that into a stream ?

[beenthere]

Quartlow
I think the chemicals that go into treating the wood are 'locked' up and chemically bound, and are not pollutants to streams. Not something I would be fear'd of, anyway.
If burned, and turned to ash, then there may be some residuals that you wouldn't want to breath.

[Furby]

Beenthere,
The level of arsenic in inland waters has been climbing slowly for years. Nobody knows why for sure, but many belive it's from the P.T. wood used in docks and seawalls. One study showed the level of arsenic climbed right along side the growth and increased installation of docks in several lakes studied.

Not saying you are wrong, just that I'm not sure I agree with you. :

[Quartlow]

Beenthere. Personaly I won't use the stuff. I just don't think its worth the risk not when there ore rot resistant woods around.

Like Furby said, not saying your wrong, but why risk it.