# Concrete over asphalt?



## Heefs Home Impr

I usually renovate indoors, and have a request to demo a garage currently sitting on ashpalt with the walls built over cement blocks.

The customer wants to expand the footprint.

He asked if it would save money to pour cement over existing asphalt.

I believe the long way around is the short way home.

Remove the existing,dig for footings and foundation wall for frost, add gravel and rebar for the new floor.

What do you think?

Thanks,Rob


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## Steve Manning

The asphalt and its base (if thick enough for what the concrete base section calls for) would be adequate to pour on. Saves the owner demo cost and cost of base material and placement.


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## ruskent

What will he save 1000 bucks?


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## tgeb

I would NOT do this, unless I could get a good layer (3" to 4") of stone over the asphalt. But that would require raising the elevation. Otherwise I would tear it out.

But I am no engineer.


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## dayexco

i'm no engineer/architect....but were this MY building, i'd be saying NO WAY!


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## jmic

dayexco said:


> i'm no engineer/architect....but were this MY building, i'd be saying NO WAY!


:thumbup: Good answer! :laughing:


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## Heefs Home Impr

*Thanks guys...*

My initial reaction was to remove and replace everything , same as interior renos.It rarely pays to goof around with square pegs and round holes eh?
The customer asked me to look into it though , I value this site for the expertise and appreciate your time.
I will start fresh and build on new footings,foundation so I can see it standing square in the future.

Thanks


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## Steve Manning

here is a link to a page from the portland cement association website covering this topic. The process is called whitetopping

http://www.concretethinker.com/Papers.aspx?DocId=12


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## Blackhammer

I thing the asphalt is the problem. Asphalt sub-base is great for pouring concrete on when compacted properly.


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## Vinny

I did this at my shop. I poured an 8" slab with rebar over an asphalt floor. 

There was no reason to remove the asphalt as we wanted to raise the elevation anyway. 

To date, no adverse effect and its been about 5 years. I would say as long as the aspahlt and its base are sustantial, it should be fine.


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## maverik

Hi all, I am really glad I found this forum, we are a small concrete business, no pavers just concrete but we do well. I am loving this concept of whitetopping and actually did a small experiment project on a friends property that had a small asphalt area in the back, to me and anyone I show the comments are always very good, especially the "green" aspect of this, I am wondering if it's worth it to expand my business and try to get into this area and promote it. With all the talk of "green" alternatives to everything, this looks to have a great future. But I mainly do residential, so that will be a problem unless I hit the people with asphalt driveways and that will be small jobs. Do I still need to use 4250 PSI concrete ? What about permits, I am in an area with some tough regulations so I can predict a lot of paperwork. Wondering if it's worth it for me to look into this more. Any thoughts??


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## partssource1

maverik said:


> Hi all, I am really glad I found this forum, we are a small concrete business, no pavers just concrete but we do well. I am loving this concept of whitetopping and actually did a small experiment project on a friends property that had a small asphalt area in the back, to me and anyone I show the comments are always very good, especially the "green" aspect of this, I am wondering if it's worth it to expand my business and try to get into this area and promote it. With all the talk of "green" alternatives to everything, this looks to have a great future. But I mainly do residential, so that will be a problem unless I hit the people with asphalt driveways and that will be small jobs. Do I still need to use 4250 PSI concrete ? What about permits, I am in an area with some tough regulations so I can predict a lot of paperwork. Wondering if it's worth it for me to look into this more. Any thoughts??


 Did you go anywhere with this. I have a 25x36x37 asphalt pad in my back yard and I'm thinking about putting a 24x35 carport on it and have been trying to decide if I should tear the asphalt or is I should use concrete milk it or do a overlay and pad is in very good shape seems like a wast to tear it all out


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## avenge

partssource1 said:


> Did you go anywhere with this. I have a 25x36x37 asphalt pad in my back yard and I'm thinking about putting a 24x35 carport on it and have been trying to decide if I should tear the asphalt or is I should use concrete milk it or do a overlay and pad is in very good shape seems like a wast to tear it all out


14 year old thread and This site is for professional contractors visit DIY Home Improvement Forum


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