What To Treat Fence Posts With

[Thunderchild]

I need to put a fence in and want to treat the posts so that they don't rot. I gather bitumen is now banned for this so what replaces it ? there are loads of products out there but they seem to be spray on heavy duty paints not anything hard enough to preserve the wood for years to come.

[The Builder]

No need, Thunders. Just use treated timber.
Modern "Tanalised" treatments mean that timber can stay in the ground for years... unaffected. The usual figure quoted is 50 years. I don't doubt it, although I need to be around a bit longer to see for myself.

Use something like Cuprinol's water based coatings for decoration.

[Thunderchild]

Well I am replacing the posts because despite being just a few years old if that they are breaking because the so called pretreated posts were put in a hole, then some soil and then 1 sack of post fix and then 8 inches of soil. The posts are soaking up the water, becoming week and just snapping in the wind, the broken posts look fine inside, no decay no rot just sodden wet and so weak. As I've offered to do this for my sisters neighbor and offered to do the whole lot again even though some stands but on the basis that the ones that are in now won't last much longer due to the cock up made in putting them in I want to make sure this loot is done properly and better or it's pointless just doing the same again.

[sandyRoe]

What about screwing a length of angle iron onto to the base of the posts? Though I guess it would rust eventually.

[murraymints]

I used treated timber but also treated with a timber paint/preservative from B&Q...been in for about 8 years now no probs, I paint every two years...to keep looking nice more than anything. It is better to put posts into spikes I think...if you are in a windy area don't use whole solid panels rather those that let the wind go through..

[Thunderchild]

Yes well all posts now sold claim to be treated but there is painting a solid layer of something on and there is mass spraying them in a hurry before selling them. So I'd rather paint some more on to be sure as once in concrete and under ground it can't be done again.

[bhg481]

I put my fence up with Metposts 30 some years ago and they're still standing. The Metposts keep the post above soil level so they're not constantly standing in wet soil.

[Clanad]

Here in the U.S., posts once were treated with various petroleum based preservatives, such as creosote, which, for the most part have now been banned. The preservative of choice now is Chromated copper arsenate (CCA). While pretty effective is produces a paintable green tone to the underlying lumber or posts.

Here in the western U.S., if we have to sink a post in an area that's damp, we use something like that described in sandyRoe's response. We sink the post and then on at least two sides we drive an iron or steel fence post (like this:
http://www.fleetfarm.com/detail/Garden-Zone-Heavy-Duty-Steel-Fence-Post/0000000080164?utm_source=googleps&utm_medium=shopping%2Bsearch&utm_campaign=google%2Bproduct%20search&gslfah&;gclid=CKPOwaWD0bwCFcY7MgodOlIAfg ) (Sorry for the lengthy URL.)

The nice thing about this model is it drives easily with a sledge and the holes along its length make for driving a heavy duty deck screw or two to help stabilize the wooden post even more. We have some that are at least 10 years old and still strong and stable...

[The Builder]

Thunder, there are fence posts and ......... fence posts. I know several fencers/landscapers who put posts straight into the ground.

The difference is that they buy timber from sawmills, agricultural merchants, or builders' merchants.

75mm x 75mm posts from DIY places tend to be made from very coarse-grained, cheap timber, whereas tradespeople tend to use 100mm x 100mm. It's often home grown in this country, and tends to be much harder and more durable.

If you're not happy, then use "Metaposts", but concrete them in to take battering from the wind. Or use concrete posts.

[Thunderchild]

Well the neighbor didn't want to spend the money on the metpost's. unfortunately the posts have been chosen and they are from a builders merchant but yes they seem to be soft wood and could do with being impregnated properly, the original posts are still in good condition (almost reusable) but the outsides sow signs of being eaten.

[heathfield]

As a toddler, I watched my dad putting in posts. He would dig the hole and put a stone at the bottom of it. Then he'd rest the post on the stone and fill the hole with more stones. This meant the posts were each standing in their own individual soakaway, and not in wet soil, so helping to keep excessive moisture away from the wood. Those posts lasted for I don't know how many years.

[Thunderchild]

well it's all going in today, I got some wood treatment and heavily painted them, Putting them into solid concrete with a concrete "neck" up to ground level to make sure they can't sit in sodden soil.

[lilacben]

We are fed up with wooden posts rotting no matter what. So have just ordered some cement ones.

[Uriah Heep]

Posts tend to rot at the point they meet the ground rather than above or below it. Best thing is get some used engine oil and put it in a container (half barrel/drum is ideal) and stand in it as many posts as possible for at least several days to soak just a little more than the part that will be in the ground The longer they are soaked for the better. I guarantee that this beats any current treatment on the market. If you think the oil is too viscous add diesel. The drier the timber the quicker and better the oil penetrates.

[penelope2]

I stand the ends of the posts in a container filled with Creosol (not Creasote) and let them soak in for a couple of days. This usually impregnates the wood right through.