Setting Posts

[Jerry Bruette]

I need to set two 6x6 posts that will be used for hanging something. I see a product at the local big box called Fast 2K, it appears to be a two part expanding foam type product.

Anybody ever use this stuff or hear of it?

I'm considering using it instead of concrete...it sets faster but it won't add any extra ballast to the bottom of the post.

I can't get these posts any deeper than about 30 inches, then I hit ledge rock, and I'm thinking the extra ballast of the concrete would be nice but would make the job take longer.

[Tom M King]

I'd use concrete. Just put plenty of water in the hole after the post is in, and pour the concrete mix into the water. It won't be maximum strength, but it works fine for that purpose. That way there is no mixing required.

[Mike Lassiter]

use quick setting concrete in bags. It sets fast enough to stabalize the post in the hole and is easy to work with. I would not put water in the hole before pouring in the mix. It would be very easy to put too much water in where the concrete mix would be too soupy (thin, watery) and would not hold the post until it set.

[Tom M King]

I've done it many times. All of our gate posts on the farm were set that way. Any water the concrete doesn't use wetting it as it goes down floats to the top. Pour in slowly, and it all gets wetted as it goes down. Some people just pour the dry concrete in the hole, and let it set over time. The concrete holds the post just fine. I do use a helper to hold the post while another pours in the concrete. You can't do much moving of the post after the concrete is poured in.

[Al Launier]

I prefer to use & pre-mix the quick set concrete as I want to better control the consistency. Also, I like to coat the part of the post with paint or even oil that is in the concrete as I'v been told by "old timers" (many years ago) that it helps to prevent wood rot. Most people don't do this these days as it is an extra step.

[Tom M King]

I remember when some folks dipped the post into tar or basement waterproofing in five gallon buckets. We have some of the old type of ground contact treated posts that have been in concrete since 1980 and are still fine. Current type of treated wood lasts maybe ten years in concrete. All line posts in that newer fence just set in dirt are still good. We have red clay subsoil here that doesn't drain very well. We have miles of fence, and I can't say how many gates, but at least a dozen all 14' wooden on 6x6 hinge posts. All the gates sit on blocks on the latch side, but posts set this way hold the heavy gates level when they swing just fine. They're set about 3' deep because that's as deep as the tractor auger goes. I'm sure those gates would sag regardless of how the concrete was "mixed" if they didn't set on blocks on the latch post when they are closed.

Here's a picture of the fence, but I can't easily find a picture of one of the gates: http://starbornhavanese.com/images/DSCN0916.JPG It's an old picture. Those Leyland Cypress trees are forty feet tall now, and the fence and gate posts are still fine.

[Al Launier]

"some folks dipped the post into tar or basement waterproofing in five gallon buckets" - now that is a great idea! much better than paint or oil. Glad you mentioned it.

[Brian Henderson]

I need to set two 6x6 posts that will be used for hanging something. I see a product at the local big box called Fast 2K, it appears to be a two part expanding foam type product.

Anybody ever use this stuff or hear of it?

I'm considering using it instead of concrete...it sets faster but it won't add any extra ballast to the bottom of the post.

I can't get these posts any deeper than about 30 inches, then I hit ledge rock, and I'm thinking the extra ballast of the concrete would be nice but would make the job take longer.

I don't know if it's the same product, but I saw someone using a similar product in a video, a foam advertised for setting posts, and he said that it was nowhere near as secure as concrete. I wouldn't risk it.

[Mike Henderson]

I'd use concrete. Just put plenty of water in the hole after the post is in, and pour the concrete mix into the water. It won't be maximum strength, but it works fine for that purpose. That way there is no mixing required.

I prefer to use mixed concrete, but if I do as Tom suggests, I put the mix in and then add the water. The problem with putting the water in first is that you generally have too much water, and unless you're very careful the mix will separate. Also, the water generally gets dirty and you get stronger concrete with clean water.

If I put the mix in first, I carefully add the water - not too much - and may come back and add more water after the initial water soaks in .

Mike

[Jerome Stanek]

I had some posts that the frost heaved them up even though the holes were 4 ft deep the frost would heave the ground and the concrete would stick to it and then not go back down. I pulled a couple of the post and the hole was still there but the post was sticking up about 12 inches over time.

[George Werner]

Just based on the cost I'm seeing for the Fast 2K, I would definitely go with concrete. Looks like the concrete is about 1/3 the cost of the Fast 2K.

[Kent Adams]

A 6x6 post is huge, not sure what your hanging on it, but I recently did a 4x4 post using quick set, mixed in a wheelbarrow, then into the hole. I don't know about the foam you're talking about, but if its open cell foam, it might trap moisture and prematurely rot the wood. If you do decide to use concrete, don't be intimidated, its rather easy. Also, I cap my post above ground and crown around the post. This way, rain flows away from the post. You can use a concrete dye to color the concrete to blend in with the dirt.

[Mike Henderson]

A 6x6 post is huge, not sure what your hanging on it, but I recently did a 4x4 post using quick set, mixed in a wheelbarrow, then into the hole. I don't know about the foam you're talking about, but if its open cell foam, it might trap moisture and prematurely rot the wood. If you do decide to use concrete, don't be intimidated, its rather easy. Also, I cap my post above ground and crown around the post. This way, rain flows away from the post. You can use a concrete dye to color the concrete to blend in with the dirt.

Concrete is pretty easy and not very expensive if you mix it yourself (don't have it hauled in by truck). But it's heavy. The bags are heavy and the mix is heavy. It's always nice to have some young, strong helpers if you're doing any amount of it. At my age, about the most I'll do by myself is a post hole.

Mike

[Kent Adams]

True on the heavy bags. I don't think I'd do much more than a post hole either. One thing I forgot to add is that rare is the even distribution of portland cement from bag to bag. The water recommendations are a starting point I've found. Recommended water amounts per bag might work for 1 out of 4 bags from my experience. I just bring a measuring cup with me and add a little at a time after the recommended water amount until I get a peanut butter like consistency.

[Jason Roehl]

To help prevent rotting of the post, put gravel in the hole to allow for drainage beneath the post, and set the post on top of the gravel, with the concrete around the post. Coating the post is also a good idea.