We just had all the holes for our PT wood pier foundation drilled. Everything went real smooth, but we hit a huge boulder about a foot down in one hole, and consequently our hole ended up veering off about 8'' and going down at a pretty bad angle. In order to get the post where we need it, could we just fill the hole with concrete up to the top of the rock and set our post on that? Or would the soil (clay) grab the concrete and push it around in the winter? Is there a better way to deal with this?
Thanks,
Andrew
Quote from: Ernest T. Bass on June 02, 2008, 12:48:33 PM
We just had all the holes for our PT wood pier foundation drilled. Everything went real smooth, but we hit a huge boulder about a foot down in one hole, and consequently our hole ended up veering off about 8'' and going down at a pretty bad angle. In order to get the post where we need it, could we just fill the hole with concrete up to the top of the rock and set our post on that? Or would the soil (clay) grab the concrete and push it around in the winter? Is there a better way to deal with this?
Thanks,
Andrew
If it was me I would clean out the hole real good and set the post on the rock. Then I would put some Re/Bar bent to go into the deep part of the hole and attach it to the post with a bolt going thru it and the re/bar bent around the bolt. Then fill the complete hole with concrete. It won't lift out and if the post is in the concrete it would be just like being deep even if it angles and will hold good. If the hole is realy big you could save some concrete by putting some stones in the mix as you fill it up. Mark
Thanks for the suggestion, Willy. The rock isn't flat enough to set the post on, thought. The rebar would certainly hold the post down, but I'm a little unsure about putting concrete around the wood post.. Post shrinks, gap gets moisture in it, moisture rots post and splits concrete when frozen?
Quote from: Ernest T. Bass on June 02, 2008, 01:00:59 PM
Thanks for the suggestion, Willy. The rock isn't flat enough to set the post on, thought. The rebar would certainly hold the post down, but I'm a little unsure about putting concrete around the wood post.. Post shrinks, gap gets moisture in it, moisture rots post and splits concrete when frozen?
I have never had that problem with a post before in Eastern Washington and it gets 11 below zero out and colder. When I set posts I don'f fill concrete to the top of the hole either. I normaly have around 4-6 inches of dirt and cone it at the top for draining reasons. You could tar around the concrete up onto the post a little to keep any water out? All the 6x6 - 60% retention pressure treated posts (21) on my cabin are set in concrete. Each post sits on a 4" thick pad and 24" of concrete is around each one in a 12"+ sq hole up to 4 inches to the top. All my pole buildings were done the same way even by contractors and also inspected. They used the same type posts. I did have one contractor put felt pad around the post when he poured the slab later but nothing in the hole. Mark
How about some concrete to level the bottom - a piece of plastic pipe around the post with gravel inside and out -- sometimes you can get scrap sewer pipe at construction sites - the Ice /frost heave won't be able to grab the post well with the plastic pipe -- like the bigfoot in a way. Moisture should still drain away
Your only talking about one hole....I think.
I'd go with Glenn's idea. That still gives you the vertical support even though you've lost some shear bracing. I would make sure to use knees or cross bracing to make up for that lateral support you don't have. The frost heaving won't be a factor if your sitting on a boulder.