I was wondering if you guys had any tricks or methods for attaching wood railings specifically the 4×4 posts to a concrete porch. I haven’t had a great deal of experience with this and when i ran into a cement porch in the past the homeowner wanted the posts in the ground surrounding the deck so it wasn’t an issue. But in this instance the homeowner wants them to be attached directly to the porch.
I have heard of people using post bases the galvanized type that you drill into the concrete then attach the post with four small nails but to me it doesn’t seem likely that it will survive the lateral loads. Also to complicate the matter these railings are at a group home operated out of a residence and these people are generally pretty heavy and strong so I want to error to the side of caution and make it stronger than in needs to be so that i don’t have frequent callbacks. I know that they are leaning toward pressure treated stock but i think they could be convinced to spend the extra money for vinyl or composite because I know those are easier, at least in theory, to attach to concrete.
If any one has suggestions I would appreciate them.
Thanks
Replies
Best approach is probably to bore a hole in the concrete, epoxy a piece of pipe several feet long into that, then drop a bored post over it. Boring the hole in the post is of course a trick.
epoxy a piece of pipe several feet long into that
Which is limited a bit, by the thickness of the concrete slab. Not much use in boring clean through a 6" thick slab to then epoxy 2' of pipe into that.
I've used 1 1/4" allthread epoxied into concrete for wooden rail posts. This has an advantage in that you can spin a nut down to hold a washer combo to hold the post off the concrete. If you build the rails and posts in advance, the nut underneath allows for some leveling, too.
Now, to bore a post, just tell it a dull story <sorry>. Actually, a plywood jig lets a person rig a slide into a horizontally clamped drill. Which can be convenient if there's more than a couple of posts to drill out.Occupational hazard of my occupation not being around (sorry Bubba)
A 6" slab is fine to anchor the pipe -- you want the pipe to stick out the top, not the bottom. It's if the slab is only 2" thick that one would have a problem, due to the potential for breakout. I'd guess that about 3" is the minimum for a single pipe anchor, given the stated criteria.
You're right about the Simpson bases not being able to keep the post standing up without some type of top brace.
The vinyl and composite might be easier to attach to concrete (but I can't imagine why), but they are not as strong as PT lumber and would be a poorer chaoice for deck railing, especially the structural portion.
I'm sorry, I thought you wanted it done the right way.