Repair and overlay existing asphalt parking lot

[gcbhhb]

Good afternoon. I have a few existing parking lots that have a asphalt buildup varying between 2.25" to 4.5"+ and then one lot with an unknown thickness. The parking lots do have some cracks, but not too excessive. Areas that appear to be in failure will be receiving full depth repair. I have 2 questions. What is the thinnest I can mill in the areas that are 2.25" without leaving the remaining asphalt to thin to be damaged prior to resurfacing? 2nd question would be, if I was to just place a tack coat and an 1.5" overlay, how should the existing cracks be repaired? Would placing tack coat and a 1/4" leveling course fill the cracks prior to the 1.5" overlay? I've read that it is not recommended to crack seal prior to an asphalt overlay. These are in northeast Ohio. Thanks.

 

[Ron]

You can mill your 2.25t thickness to 1 inch without difficulty. This will allow you a reasonable overlay. No need to repair cracks before overlaying. Use a crack relief layer or a synthetic grid instead. I would not recommend a thin leveling course....It is better to used controlled milling than to use a leveling course.

 

[gcbhhb]

Ron - thanks for the reply. Leaving only 1" of asphalt after milling, will that hold up under the weight of the pavers and asphalt trucks?
Unfortunately, the use of a crack relief layer or a synthetic grid is not feasible due to cost. We only have enough funds to place a 1.25" to 1.5" overlay, so I don't want to place a grid with that thin of an overlay, I've seen issues with placing thin overlay and using fabric/grid.

 

[Ron]

gcb.... Yes, 1" will hold up fine under paver and truck weights for reconstruction. I live in the land of thin asphalt and even thinner overlays! It's done routinely here.

If you can do grid or crack relief, then fill all cracks before overlaying.

 

[gcbhhb]

Thank you.