OVERLAYS / RESURFACING
WHAT IS AN OVERLAY?
Resurfacing an area involves the placement of one or more asphalt overlays on top of existing pavement. A hotmix asphalt overlay can include a leveling course to even out the pavement surface and a second uniform coarse to provide the necessary thickness. Resurfacing in parking lots generally requires only one overlay.
When preparing pavements for resurfacing, the base must be completely clean in order for a tack coat to adhere. This tack coat will ensure that the new pavement sticks to the older asphalt surface.
Asphalt paving, especially on a large scale like a parking lot, or condominium roadways, is a significant investment, so you want to make sure you actually need what you’re buying.
OVERLAY vs SEALCOATING
Properly constructed asphalt pavement that is maintained in a timely manner can last 15 years or more. Sealcoating is a part of the maintenance process and so are strategic pavement repairs of smaller areas. But eventually, to extend the life of your pavement (and reduce its life-cycle cost) you’ll need an asphalt overlay, which simply is another layer of hot mix asphalt that’s constructed on top of an existing pavement.
And, particularly in the case of overlays, timeliness is key. That’s because once a pavement deteriorates past a certain point, an overlay investment is essentially a waste of your maintenance dollars. Sure, an overlay will always improve the appearance of your parking lot or other pavement. But if the pavement on which the overlay is constructed has deteriorated too much, the overlay itself will deteriorate quickly.
Unlike sealcoating, an inexpensive process that looks good and provides a protective coating that helps extend pavement life, a 1.5” to 2” thick asphalt overlay actually provides structure to the existing pavement; an overlay strengthens the existing pavement. But an overlay doesn’t provide strength where there is none—it adds to the strength that is already there. So an overlay can’t enhance the strength of existing pavement that is too damaged and too weak. In other words, the overlay is only as strong as the pavement beneath it, so make sure an overlay is the right course of action.
But make no mistake, to get the most out of your pavement investment you will, at some point, need an overlay—and with proper maintenance a second overlay can extend pavement life even further (driving those life-cycle costs down as your pavement lasts longer and longer). Just make sure the existing pavement is strong enough to take full advantage of what an overlay can provide.
OVERLAYS WITH FABRIC
An overlay (also referred to as resurfacing) as its name implies, is simply a new layer of pavement (typically 1.5” to 2” thick after compaction) placed over top of an existing pavement surface, provided it is not too far gone. Nowadays we find ourselves recommending a fabric interlayer such as Petromat or Glasgrid before applying the new asphalt. In addition to helping act as a moisture barrier, fabric interlayers help reduce reflective cracking from the original surface into the new overlay. When constructed properly and at the appropriate time in a pavement’s life cycle, an overlay helps extend the life of your original pavement by 15 years or more, giving you a greater return on what you have already invested in your parking lot or driveway. [MORE]
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