Going to add diagonal supports to post and pier foundation -- what materials to use? | Page 2 | Construction and DIY projects | Forums

Hi, this is my first post. I'm not a builder/contractor but have hammered up quite a few shacks in my time. I agree with Kvr that supplemental beams running the 32' way, midway between your center beam & the outer one, would help--I'd use something a bit larger though like 4" x 8", with 4 x 4 posts under it at 0', 4', 8', 12', 16'... You don't need to dig holes for these, just make them tight on concrete blocks, etc, or just use cheap bottle jacks & leave them there. If you still want to put diagonals in, those little pieces like the pictures show won't do any good, you'd do better using 4 x 4 treated posts extending diagonally between some of your longer posts, pick one in the middle & put a diagonal at the base of each side of it & go upward to the next post each way, forming a triangle. Two sets like this will take care of whatever movement you're getting from down there. It's also possible that the weight of your 1 1/2 story house is moving it back & forth a bit due to a lack of sheathing, which would really stiffen it. What are your inside walls made of? The movement when kids run up & down stairs shouldn't have any relation to the floor joists, if the stairs are properly based. If the stairs are just bottoming onto random floor joists the whole staircase might be flexing the floor. You might check that first to see where the stairs hit the floor & possibly just put piers, etc under there.