PDA

View Full Version : Concrete overlay on cement board?


pattyg2
Jun 11, 2010, 07:14 PM
I was wondering if anyone has done a concrete overlay on cement board for flooring applications.

21boat
Jun 11, 2010, 08:53 PM
Hi patty, is there a thickness problem needed for building up the floor. More details would be good here

pattyg2
Jun 12, 2010, 03:58 AM
No. Just wondering if it can be done. I have a workshop with wood sub-floor over part of the area to raise the height since it use to be a driveway that sloped for drainage. I don't want to tile but would like to experiment with a stained concrete overlay after putting hardi board down.

21boat
Jun 13, 2010, 09:13 AM
No. Just wondering if it can be done. I have a workshop with wood sub-floor over part of the area to raise the height since it use to be a driveway that sloped for drainage. I don't want to tile but would like to experiment with a stained concrete overlay after putting hardi board down.

Hi patty, I might be a little slow this morning the post is a little hazy to me. See if I get it right.

You have a wood sub floor over what? The existing concrete floor? Or is it you have a wood sub floor to raise the height, Why is drainage involved in here?

So I take it you have a wood floor, want to use hardiboard over wood floor and then strained concrete over that?

Problem here is it's a WOOD floor with concrete over it. Look at it this way, A yard of concrete is about 4,lb per yard. 4" thick Crete, 1 yd does about 82 square feet. Normally stained concrete is min 4" thick for general foot traffic. Thinner stained Crete would be a counter top which doesn't get foot traffic. The other problem is holding the wet concrete and the wood floor slowly sagging while it sets or the wood floor FAILS over the weight of the wet Crete. Bottom line this is a very Bad idea unless you tear out wood floor set up a proper decking to pour Crete on.

pattyg2
Jun 13, 2010, 09:44 AM
I have a concrete floor in my shop. It was a driveway at one time. The low end was built up using sleepers and 1/2" wood t&g planks. The area is enclosed so no drainage problem. I wanted to do a concrete overlay which can be poured from 1/4" to 3/4" thick.

21boat
Jun 13, 2010, 01:05 PM
I have a concrete floor in my shop. It was a driveway at one time. The low end was built up using sleepers and 1/2" wood t&g planks. The area is enclosed so no drainage problem. I wanted to do a concrete overlay which can be poured from 1/4" to 3/4" thick.

Let me ask you this. How much height did the sleepers have to be to level out the floor. Wouldn't it be easier to slurry the whole floor with a product that can work better. That 1/4 inch, will that terminate in the floor somewhere or at a side wall of the structure?

What product were you thinking for the "Overlay" Also are we taking into account the expansion and contraction on a slurry leveling coat.

Don't know what the area size is but lets think of the labor and material cost here. Tapconing hardiboard down. Stainless tap cons. Then the leveling agents restrictions and requirements. Personally I'm thinking it would be easier to pour new Crete 3" min over old floor and thicker in the sleeper area.

I hate to see material mixes such as this. Conc floor, sleepers, T@J board, hardiboard, slurry coat. The more that's added the more can go wrong. Can you post the slurry product you are thinking of?