again, here was our situation: 15×33 concrete patio that’s about 30 inches off the ground. the outside of the patio is cinder blocks with one layer of bricks on top of the outer edge. we needed to put up railings to make place secure for our 1 year old son.

when we started on the first side (short ends) we used anchors to secure the posts to a base and the concrete. in the store they told us to use nails for the bases, which was a mistake. each time we nailed on to the base the anchors loosened. so we changed to screws which made a huge difference.

the other thing we were unaware of and nobody at the store told us either, is that the bases we used really need support from the top too. of course we don’t have that, so to make the railings real sturdy we followed Bob’s advice and used buttresses on the back of the 4×4 posts. you can see his drawing if you scroll up the page.

that made a big difference especially on the long 33 feet run.

thanks again

Stefanie

Concrete Deck:

Buttress Post:

Post Mounting Bracket:

Finished Deck Rail:

Rail Fastened to Wall with L-Bracket:

Reinforcing Bottom L-Bracket:

Use a 4×4 spacer block to span the gap between the deck rail post and buttress post. I forgot to draw in a sloped top for aesthetics and the dimensions are approximate. Take care to pattern your wood screws to avoid hitting the screws in the spacer block.

Set the horizontal concrete anchors at least 4″ below the edge of the patio. Anchors set at 4″ and 8″ below the patio on the brick wall will be quite strong.

My question/concern is how deep is the concrete patio slab – most slabs are 4″ to 6″ – and the thickness of the concrete footer wall for the brick facing; it could be cinderblock behind the brick or 4″ to 6″ of concrete. Drill a 1/4″ hole in a brick joint to see what’s behind there first. I think you’ll be OK setting the 1/2 inch diameter concrete anchors.

You can e-mail a photo to me from the contact page: http://www.handymanhowto.com/contact/

since we knew we couldn’t drill holes in the bricks to set our anchors, we drilled our holes about 6 inches in. the railings (panels) would then be attached to the back of the 4x4s. if we were to use a buttress for each 4×4 we would have to drill holes in the bricks.

i would like to upload a photo to show you but don’t see an option for photo uploads.

thanks

My method used 5-1/2″ long concrete anchors to secure the bottom posts to prevent “kick-out” and this method alone does not provide sufficient cantilever rigidity for the top rail. Notice that I secured the top rail of the deck rail spans to either the 8″x8″ main deck support posts or the 4″x4″ post of the staircase.

If your concrete deck lacks pre-existing support posts to secure the top deck rails, a buttress configuration could work based on my technique. This means doubling-up the 4×4 support posts, setting the posts on long concrete anchors and fastening the posts together using 5-1/2″ or 6″ long wood screws. The height of the buttress post should be about 2/3rds the height of the main post. The posts should be spaced no more than 6 feet apart.

This drawing illustrates the buttress configuration:

Send a photo and let me know how it works for you.

since we only done 2 short sides that way and still have one long side to go, we want to try your method for that. our question is though, will your method also be sturdy enough for a deck railing of 33′? we’re worried that the length of the deck is gonna make this (and definitely the method we used today) less sturdy.

do you have any suggestions for that?

thanks,
stefanie