Concrete Patio area
#1
Group Moderator
Thread Starter
Concrete Patio area
We have a concrete patio area as you step out the backdoor. There is about a 4 inch drop from the door threshold to the patio.
The concrete patio area is about 6' X 10' area. For some reason, an area of about 3' X 3' square on one corner, was poured separately. So, imagine this 6X10 area with a 3X3 separate square on one corner that is part of the 6X10 patio.
Because its within the 6X10 section, but is a separate 3X3 square, not only does it look stupid but it is about 2" lower than the rest of the 6X10 area. So, we want to form up around the entire 6X10 patio & pour about a 2" overlay to make it all one piece & of course make it level/same height/even.
Because its just a patio & wont have to bear a lot of weight &
because it will only leave about a 2" drop out side the back door, would you recommend or not, pouring a 2" overlay or not? Why not? & Other than tearing out, removing & replacing the concrete patio completely, what would you recommend?
The idea is to be quick, simple, cheap(er) & improve appearance.
The concrete patio area is about 6' X 10' area. For some reason, an area of about 3' X 3' square on one corner, was poured separately. So, imagine this 6X10 area with a 3X3 separate square on one corner that is part of the 6X10 patio.
Because its within the 6X10 section, but is a separate 3X3 square, not only does it look stupid but it is about 2" lower than the rest of the 6X10 area. So, we want to form up around the entire 6X10 patio & pour about a 2" overlay to make it all one piece & of course make it level/same height/even.
Because its just a patio & wont have to bear a lot of weight &
because it will only leave about a 2" drop out side the back door, would you recommend or not, pouring a 2" overlay or not? Why not? & Other than tearing out, removing & replacing the concrete patio completely, what would you recommend?
The idea is to be quick, simple, cheap(er) & improve appearance.
#3
Group Moderator
Thread Starter
Thanks for your input Pulpo & it is a very good option for some people & situations I am sure. However, a brick patio is not something that would be appealing for me & my tastes. So bricking it aint gonna happen. I think I'll stay with a concrete patio in my situation.
Seriously, thanks for your input though.
Seriously, thanks for your input though.
#5
Forum Topic Moderator
I've always heard that 2" concrete overlays didn't need any special prep but keep in mind that the new concrete will look different than the old and may never completely blend in. Hopefully one of the concrete guys will chime in with better info for you.
#6
Group Moderator
Thread Starter
marksr,
It will be a complete overlay so looking different wont be an issue. Thanks for your input.
It will be a complete overlay so looking different wont be an issue. Thanks for your input.
#7
I have considerable concrete overlay experience, starting in the early 1970s. Many years of my DOT career were spent designing, constructing and inspecting them. For starters, and contrary to what you think, doing them correctly is neither quick, simple or cheap, as many aspects of placing concrete overlays are easy to screw up, often resulting in performance problems. And ignore what marksr said about not needing any special prep--the vast majority of failed overlay installations that I've observed are primarily the result of improper surface preparation of the existing concrete surface being bonded to.
If you're serious about doing it, talk to some professional concrete people for estimates, making sure to ask them how many overlays they've done. You may learn enough to save you a lot of grief.
If you're serious about doing it, talk to some professional concrete people for estimates, making sure to ask them how many overlays they've done. You may learn enough to save you a lot of grief.
#8
Forum Topic Moderator
Not questioning your expertise, just trying to better understand. I know thin overlays can be problematic if not done properly but have always heard that overlaying concrete with more concrete was almost fool proof IF the new concrete is 2" or more thick. What kind of problems arise with a thick overlay? just trying to learn

#9
Improper surface preparation (not adequately cleaned, or scarified, or existing delaminations removed) will always lead to debonding of the overlay from the parent concrete. Once that happens, the overlay will proceed to crack and break up, leading to further debonding, with water and dirt getting between the overlay and parent concrete. In freezing climates, unlike the OP's location, once ice starts doing its thing in the interface between new and old, further debonding and breaking up of the overlay is inevitable.