Preventing post rot after the fact?

[piaffepony]

My outdoor arena fence posts are the 7” round PT posts from TSC. They were set in concrete 5 years ago. The bottoms weren’t coated, we didn’t use enough concrete to keep the soil and moisture away from the base and half of the posts have broken off at the concrete. No surprise there!

I bought more posts and coated the bottoms and painted the crap out of them before we set them. However, storm debris took out another 7 posts. I had a ton of volunteers come help set a total of 15 posts. I didn’t have time to coat the newer posts before they were set in concrete.

1. Will coating the bottom of the posts with tar (open to product recommendations) where it meets the concrete work ok? Would a wood crack filler around the bottoms work or be better? Or will it be all for not?

2. Anything I can do to the original posts that probably have a little rotting to extend their life a few more years?

3. The newer PT posts are still damp.. will any post treatment stick to it?

 

[RNeumann]

The premise that concrete keeps moisture out isn’t correct. Concrete is a sponge that holds moisture. Unfortunately the posts you bought won’t work and no coating will change that. Their are hundreds of “pressure treatments” and the TSC ones don’t work for your needs- read inferior treatment.
Either switch post material or switch the way the posts are set. If the water table is low enough switching from concrete to gravel would be a start.

 

[SPYDERLK]

My outdoor arena fence posts are the 7” round PT posts from TSC. They were set in concrete 5 years ago. The bottoms weren’t coated, we didn’t use enough concrete to keep the soil and moisture away from the base and half of the posts have broken off at the concrete. No surprise there!

I bought more posts and coated the bottoms and painted the crap out of them before we set them. However, storm debris took out another 7 posts. I had a ton of volunteers come help set a total of 15 posts. I didn’t have time to coat the newer posts before they were set in concrete.

1. Will coating the bottom of the posts with tar (open to product recommendations) where it meets the concrete work ok? Would a wood crack filler around the bottoms work or be better? Or will it be all for not?

2. Anything I can do to the original posts that probably have a little rotting to extend their life a few more years?

3. The newer PT posts are still damp.. will any post treatment stick to it?

You should probably plant the pressure treated posts directly in the soil without coating. They seem to rot more readily inside a semi sealed coating. Ours planted bare are looking good after 10yrs. - - Also, maybe, there are differently treated posts on the market. We have never bought ours from TSC.

 

[oosik]

If if were me, I'd quit worrying about the posts you have in now. As they rot out replace them with REAL railroad ties. I've had ties in a swampy area now for 38 years with no evidence of rot. You have a pretty tough environment if a 7" post rots off in five years.

I'm not speaking of the product sold at Lowes, Walmart or Home Depot. The ties I got were directly from one of our local RR supply facilities. They were heavy, gooey, and smelled strongly of asphalt tar preservative. Even after 38 years - they still smell strongly on a hot summer day.

 

[RoyKing]

Lowes sell a rot treatment base on cu. Yearly spraying of the posts and don't bother with concrete, put same dirt back in the hole and water it as you go and they will settle in quickly.

 

[piaffepony]

They are already set... I can’t change it now. Now I’m just trying to minimize the future damage.

 

[nybirdman]

What the Amish do is;drill an angled hole below the ground line and fill with used motor oil.Refill every couple of years.Do know how well that goes with the environment tho.

 

[bcp]

Something can be done, but I don't remember much about the news article. Sometime in the 80's, I think, they drilled holes into the interior of the post near the bottom, put something in, then sealed the hole with a wooden plug.


Hundreds of posts in the stockade at Fort Vancouver:

Fort Vancouver National Historic Site (U.S. National Park Service)

Bruce

 

[Snobdds]

What the Amish do is;drill an angled hole below the ground line and fill with used motor oil.Refill every couple of years.Do know how well that goes with the environment tho.

I do a yearly treatment of motor oil (new cheap 30 wt) thinned down with diesel. I never replace post...

The greenies hate me...

 

[zzvyb6]

Buy lengths of angle iron and pound them alongside your round posts. Drill holes in the iron an secure with big nails. Old highway sign steel is the best because its pre-drilled. This will relieve some of the strain on the existing posts. What's between the posts (boards, wire, nylon webbing)? Keep that as tight as possible to have the neighboring posts help the weak ones. I just run a new post alongside the old ones and NEVER use boards because of the length compromise issues.

 

[MH8675309]

I never set posts in concrete. I auger out the hole then clean out the excess with a hand post hole digger. Set the post in and tamp the dirt in with a steel tamper (this is just a piece of 3/4' round stock 5' long with a 2"round 1/2" thick steel cookie welded to one end) until the dirt is packed in good and the post is firm. Here (Michigan) we put posts in 42" deep so that the frost doesn't heave them up. OOsik is right about the railroad ties but if you're using it for an arena you probably dont want your horse - or you touching sticky creosote. Attached is a picture of our 60' round pen. It is ten years old.

 

[oosik]

MH8675309 - I forgot this was for an arena. For sure - you don't want your horses anywhere near a treated RR tie. Ever seen what a cow looks like after a good "rub up" on an old pine tree. It ain't pretty......

 

[EddieWalker]

Keep it simple. Concrete needs to go above the solid around it, and slope away from the post. Kind of like a volcano with the post coming out the middle. Posts can handle moisture, and they can handle dirt. What they cannot handle is the wet/dry cycle that happens when a low spot forms around the base of the post. This is from filling with dirt, not enough concrete, or mowing next to the post and eroding the soil built up next to the post. Mix the concrete fairly dry so it will keep it's shape, and build it up around the post.

 

[RustyA]

Up North frost is the enemy of fencing. Concrete just gives it something bigger to push against. We wrap any wood posts or railroad ties in garbage bags to make post slicker so frost can't get as much grip and heave it. Every spring while ground is moist have to go around with a mallet and tap steel t-posts back down...not a problem down south

 

[Sawyer Rob]

Where I live, nothing protects the post, concrete just makes it worse... The wood shrinks away from the concrete, and the water just sits there...

Pounding steel (as stated above) along side the post does work pretty good though...

Getting "marine grade" post solves the problem too, but they are very expensive...

SR

 

[quicksandfarmer]

Something can be done, but I don't remember much about the news article. Sometime in the 80's, I think, they drilled holes into the interior of the post near the bottom, put something in, then sealed the hole with a wooden plug.


Hundreds of posts in the stockade at Fort Vancouver:

Fort Vancouver National Historic Site (U.S. National Park Service)

View attachment 596579


Bruce

Probably penetrating epoxy. It turns rotted wood into a plastic composite that's stronger than the surrounding wood. In fact you have to be careful you don't just create a shear spot where the epoxy ends. I've used it with good results, but it's expensive.