DIY Message Boards
Floating Concrete Slab Deck

This topic can be found at:

Oct 24, 2013, 09:45 PM
Floating Concrete Slab Deck
I have an existing deck that is about 3' above my back entrance. It is a traditional wooden deck, but the top is a lightweight concrete slab. I don't know the thickness because it's finished on the edges, so it appears 3", but is likely less than half of that.

I want to extend the deck further and tie it into the existing one seamlessly. I know that I can tie rebar into what is there to join the two pieces, but can I realistically make it look like one continuous slab without having a joint where the two join?

Alternatively, could I chip out some of the existing concrete and join them with a fresh pour of concrete?

Any thoughts or tips? I plan on having a contractor do it, but I want to make sure that I have the right information and am not sold the wrong thing.
Oct 24, 2013, 10:44 PM
The only way you can hide the seam will be to do an overlay on the entire new and old slab surfaces.

You can likely add on a concrete layered extension that is strong enough and is similar in texture. But, you will always have a seam, you will always have two slightly different materials and you will always have two parts of a deck that were installed by different people. All of those make it impossible to make a 'seamless' seam.