Soil over asphalt?

MichaelNYC's picture

Hi,

I have a large backyard (I'm an hour north of NYC). It is half asphalt and half soil (total 50' wide).

We tried removing some of the asphalt from the yard last year and the soil beneath it was just terrible. It needed to be removed completely and replaced. That's OK for small sections, but not for a chunk that's 25' x 25'.

So my question: we really just want to grow grass where the asphalt is. Is there any reason why I couldn't lay down some landscaping fabric over the asphalt and then put down 8-10" of soil and treat it like a raised bed? The yard is on a slight slope and needs to be regraded a bit anyway -- I thought that with the proper retaining walls this would be a good solution -- and at least keep all that asphalt out of the local landfill.

Any thoughts?

Many thanks,

Michael

Scarlett007's picture

(post #10320, reply #1 of 7)

Well, good luck, I honestly don't know if that'll work? I get you though, oh how awful it is, when asphalt comes up. Why not rethink, use the hardscape as a place where you can sit, enjoy the garden, have a water feature there, maybe put some on top of the asphalt, even concrete can be tinted these days to look like natural stone! You could build raised beds all around the edges, you'd have no problem with soil then. Use them for flowers, vegetables, whatever you like? Good Luck and Happy Landings!

live, laugh, love, Rebecca

Check out GoSucculent.com ask anyone!!

live, laugh, love, Rebecca Check out GoSucculent.com ask anyone!!
KimmSr's picture

(post #10320, reply #2 of 7)

Drainage will be a problem, any soil you put on that will tend to be too wet.

West central Michigan along the lake shore


A sign of a good gardener is not a green thumb, rather it is brown knees.

West central Michigan along the lake shore

A sign of a good gardener is not a green thumb, rather it is brown knees.

Dagwood's picture

(post #10320, reply #3 of 7)

From my experience, this is a bad idea.


Asphalt is generally treated as toxic waste and should be removed in large pieces, reground and recycled. The earth beneath your asphalt is likely "A Gravel" which is fine sand and coarse gravel.


If it was ever anything more than a driveway (reclaimed road??, Commercial parking lot??) it may have a layer of "B Gravel" beneath the "A Gravel."


Good construction dictates at least 8-12" of A Gravel, and if it is necessary to have B Gravel it will be as thick as needed to overcome drainage issues.


I would suggest that you remove the asphalt and the A Gravel. Ask contarctors in your area what they will charge to do this. It will likely take a bobcat and a dump[ trailer an afternoon if your lot is normal sized. Then you can backfill the lot with whatever soil suits your needs.


You have a unique advantage here in thta most of us have little or no control of the soils that go into our property. you can go as rich or thin as you choose, and create whatever landscape features you choose. if you are considering a pond or berms, etc. this is the time to lay it out (on paper) since you will have the equipment on site anyway.



Dagwood Bumstead


If it can die, I can kill it.
Certified Brown Thumb, 4th degree


Edited 2/27/2009 10:14 am ET by Dagwood

If it can die, I can kill it.
Certified Brown Thumb, 4th degree

Astrid's picture

(post #10320, reply #4 of 7)

To be blunt, asphalt is no problem for some landfills. Some communities re-cycle asphalt and put it back on the roads, after grinding it up and adding tar and fresh gravel or some such thing.
I would inquire about the cost of having the asphalt in your yard broken up and removed and hauled away by truck by an excavating contractor. Then you would find what kind of soil you have to work with. You might need more "top soil" added if you plan to plant grass.

New Mexico home organic gardener

Adopt the pace of nature; her secret is patience. Emerson

New Mexico home organic gardener Adopt the pace of nature; her secret is patience. Emerson
Dagwood's picture

(post #10320, reply #5 of 7)

New Mexico must have different rules than here then. Around here Asphalt and shingles are separated from the waste stream treated as toxic, and recycled where possible.


I suppose the OP would do well to check local codes.


Dagwood Bumstead


If it can die, I can kill it.
Certified Brown Thumb, 4th degree

If it can die, I can kill it.
Certified Brown Thumb, 4th degree

Astrid's picture

(post #10320, reply #6 of 7)

Yes, as far as I know that is the way things are here also. Our dump is growing ever larger still. Re-cycling is restricted to cardboard, newspaper, cardboard boxes, glass and metal. The rest is buried in plastic bags of anything and added to the mountains of trash. The semi-buried trash bags flutter in the breeze and whirlwinds of spring. That is in the municipal dumps. Outside that area county dumps are owned privately, trash is burned at home in some fashion, or buried in pits.

New Mexico home organic gardener

Adopt the pace of nature; her secret is patience. Emerson


Edited 2/27/2009 11:24 am by Astrid

New Mexico home organic gardener Adopt the pace of nature; her secret is patience. Emerson
BeeJay's picture

(post #10320, reply #7 of 7)

I got my 1000 feet of drivway paved last summer with reprocessed asphalt.  No additives. Just the ground up paving.  They like to do it in the heat of summer so that it compacts and adheres when they run the roller over it.  This is the first winter that I haven't had my gravel washing off into the woods.  Isn't it odd how a material losses it's toxic waste status when it becomes a saleable commodity?


BJ


Gardening, cooking and woodworking in South'n Murlyn'
Gardening, cooking and woodworking in South'n Murlyn'