Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. It only takes a minute to sign up.
Sign up to join this community
I'm wondering to reinforce the posts in my carport as it seems one good earthquake could throw these off.
Any thoughts on building a form out of wood and pouring concrete around and half-way up the wood post? Would that be sufficient or do I need to go further down/up? Goal is primarily to prevent slipping off in an earthquake[![enter image description here][1]][1]
Concrete does not react well with normal wood, so don't pour up along the post. That's why the little block is on top of the pier you have, its made either of pressure treated wood, or redwood. If you really want a better pier, pour one a little larger then what you have, and you can include a metal hold down or strap to make sure nothing moves later. (and you still need the little block in between the post and pier,by the way, unless you get a full column base the post sits on instead of the concrete).
If you live in an earthquake zone, it may already have a feature to prevent that, such as a central steel pin. In any case, slap-dash "reinforcing" can have effects opposite what you expect (could be your new system would break the post where it entered the concrete by concentrating forces there) - and the rot issue was already pointed out by #2448131
I would check with the planning department of your municipality to see if it was, in fact, designed to resist earthquakes as built. If so, stop. If not, consult an actual engineer to determine the best approach to retrofitting it, if it needs retrofitting.
