I am installing chainlinnk fence 4' high and I am traying to figure how much cement is needed per post? I am putting them about 15quot; deep.
There are several options that you could pursue. First things first, are you required to pull a permit from the local building department? If you are required to pull a permit and are planning to, the best way to start is to go to the building department and ask them for the local code requirements. Some building departments will have pre-printed literature for this purpose, and many of the inspectors are friendly and willing to walk you through the requirements. If you're not required to pull a permit you can remove the concrete and dig new holes for the posts and anchor them with new concrete. This will be a lot of work... if you choose this method I would highly recommend using either pressure treated 4 X 4 posts or galvanized posts. Anything wood in contact with dirt or concrete will rot if it's not pressure treated (pt). Another option might be to buy the 4 x 4 pt posts and attach them to the existing posts from the chain link fence. If the existing posts are anchored sufficiently in concrete you can buy brackets from a local hardware store that will wrap around the metal post and have a flat surface with holes for screws to attach to the wood post. This will solve your height problem of the existing posts. To answer your other question, I don't believe that using L brackets alone will be sufficient support, as soon as you have a strong wind it will bend the brackets and the whole fence will go down. Using the L brackets in combination with the existing posts would be a good idea. You can attach the brackets with concrete screws in which case you will want to pre-drill holes to keep the screws from breaking off, or you could use a ram-set.
The posts should have about 2' in the ground. For a 4' fence, I usually use one 80lbs bag per post.
Concrete Chain Link Fence Posts
I'm not why people feel the need to use so much concrete. I put in a fence using NO concrete. I used a large hammer ( or small sledge ) to drive the poles into the ground. I put them as deep as I could ( 18 ) and cut off the top couple of inches that was damaged from hammering. Attach the top runner pipes, then attached the fencing. That fence was still there 10 years later when I moved. The only need for concrete is to keep the poles from being pulled up. You know something....I've never seen a dog pull a fence up at the poles. If you feel the need...then concrete every other one.
Back in my younger years I built fences for a living. We cemented in the corner and end post completely as they were the most important. You don't want them to move when you start stretching the chain link. As for the line post in most cases we drove them in and maybe capped them with a few inches to prevent grass from growing around the post and in some cases we didn't cement them at all. The line post are there to just hold the fence up. When you stretch the chain link the line post will be pulled in line with the corner or end post so the need to cement them isn't the same. Ultimately we built the fence the way the customer wanted it built. If he or she wanted the post cemented that's what we did. For your project you have to take into account your comfort level and do what you are comfortable with. Just a note: you mentioned your depth was 15, it is pretty important to make sure your post and the cement (unless it is just a cap to prevent grass from growing) is below the frost line. If it isn't you run a chance they will move over time. Where I lived at the time our frost line was 18 but where I live now it's 12. Good Luck with your project
