We have an existing patio that is not level and not smooth. We are enlarging it and want to pour 1 inch thick concrete over the existing patio to make it all look the same and no seams. We are making the forms around the existing patio 1 inch higher then the current level. We plan to have a concrete company to pour the concrete. Is there something we need to put on the existing concrete before we pour the new concrete???
2007-03-11 12:23:05 · 6 answers · asked by sprice 1 in Home & Garden ➔ Other - Home & Garden
There are products you can paint on the existing concrete to help the new concrete bond. That's the good news.
The bad news is, it won't work. I have seen at least 20 people try this, and it never has worked. Any cracks you have in the sub concrete will, in time, transmit to the new.
Also, as previously stated, 1" overlay is not much. You may be able to get by with this practice with 4", but I suspect what you want to do is not going to work. It will look good for a while, but not long.
Save yourself some money and headaches, remove the old, and repour.
2007-03-11 12:35:09 · answer #1 · answered by Bare B 6 · 1⤊ 0⤋
I would bust the old out and pour a new 4" minimum slab. You are going to have to buy at least 1 cubic yard of concrete (most ready-mix plants have minimums) and depending on the size of the patio, you won't have to buy any more concrete to repour the whole thing. 1 cubic yard of concrete will do a 8' x 10' patio 4" thick. The only thing you will have to pay for extra is hauling the old concrete away. Just cover the side of the house with plywood and bust it out with either a saw with a diamond blade, or just use a sledge hammer.....Then form the sides with 2x4s and pour.
If you cap the patio, it will eventually have problems....If you pour new, it will last forever.
2007-03-13 18:58:56 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Lowes and Home Depot sells some stuff that you put down like a paste that will allow the new and old concrete to sit there without cracking. It will never bond the 2 concretes together. Sorry.
2007-03-11 19:34:46 · answer #3 · answered by possun33 1 · 0⤊ 0⤋
we poured over an existing pad that was small. we havent had a problem with it, but we went more than one inch higher with the new concrete.
ask your concrete experts how much difference in price to pour a completely new slab and remove the bad/old slab.
depending upon its condition may determine whether it will be a waste of money.
2007-03-11 19:32:24 · answer #4 · answered by stonechic 6 · 0⤊ 0⤋
you can paint on a bonding agent but as was just stated 1 in. is not going to work unless your base slab was perfect , if it was jointed these joints will come through. the joints are there for a reason. you didnt give a size as this will have some impact on the outcome. but if you have your heart set on getting it done, tell them you want a 4000 lb. mix with pea gravel. if the old slab is jointed have them saw cut the top slab where the old joints were as this is going to crack eventually, if you are young and plan on using this patio for years to come, i would tear it out and have it done right...should be able to get it done for 9 dollars a sq. ft or less...
2007-03-12 09:43:35 · answer #5 · answered by Anonymous · 0⤊ 0⤋
It'll crack. 1 inch is too thin. Don't be cheap, bust it out and redo.
2007-03-11 19:26:59 · answer #6 · answered by droolie_da_dog 4 · 1⤊ 0⤋