What an overlay can and cannot do
An overlay renews the surface a lot drives on; it does not rebuild what that surface sits on. Caltrans defines a thin overlay as hot mix of 0.15 feet or less placed as a maintenance treatment, corrective or preventive. That is the right tool for a surface that has aged, ravelled or worn smooth over ground that is still sound, and the wrong one over wheel paths that have already broken up, which are dug out first.
Grinding is what keeps the lot at the level it was built to. Adding a layer without taking one off raises the surface against kerbs, door thresholds, drain inlets and the stalls beside them. Cold planing takes the old surface down so the new one finishes flush, and the standard specifications schedule the work so an area is planed, paved and opened to traffic in the same shift.
Planing takes the markings off with the asphalt, so the lot is set out again. That turns a resurfacing into a restriping, and the federal brief on restriping parking spaces is clear that accessible spaces have to be provided when a facility is restriped. Chapter 11B carries the dimensions the new layout is measured against. What resurfacing does not pull in is the route into the building: an alteration by resurfacing or restriping is limited to its own scope of work, and ramps and walks are a separate job.
A parking lot overlay is not the mix a highway gets. Open-graded surfaces are not recommended where vehicles make severe turning movements, which includes parking areas, or where fuel and oil are spilled, so an open-graded surface is ruled out for a lot and the mix is chosen to take the scuffing at pad entrances and aisle ends.
What asphalt resurfacing includes
The lot is walked for the fixed points the new surface must meet: kerb faces, door thresholds, drain inlet rims, gate tracks and the tie-in to any section being left. Those set the depth of planing, and phasing is agreed so a trading property keeps an entrance open.
The old surface is ground off to the agreed depth and the millings are loaded straight out, leaving a textured surface for the new asphalt to key into.
Areas that failed through the full depth are dug out and rebuilt before the overlay goes over them, rather than being covered.
A tack coat is applied to the planed surface and the hot mix is placed over it, with joints kept out of the wheel paths and tied cleanly into the unplaned edges.
Compaction follows the paver while the mat is hot, and the area is opened to traffic in the same shift it was planed.
Stalls, aisles, arrows, fire lanes and the accessible set are measured and marked on the new surface once it is dry.
Grinding is not an extra on a resurfacing; it is what keeps the lot working. A layer added on top of the old one leaves the surface above the kerb, the threshold and the inlet it drains into.
Where an overlay fits best
Big-box parking fields
Acres of stall parking that age evenly and see light loads are the classic candidate, with the truck route down one side treated separately.
Office and medical lots
A smooth, freshly marked surface matters most where visitors park near the doors, and the accessible stalls are reset as part of the work.
Association private streets
A street the association maintains can be overlaid in lengths across seasons, which suits a reserve plan better than one large closure.
School and campus parking
Large areas with a fixed break to work in, where planing and paving in the same shift keeps the lot usable when term starts.
Strip centers between tenants
A vacancy is the moment to resurface the frontage and set the stalls out to a layout that suits the incoming tenant mix.
Warehouse car parking
The staff and visitor parking ages differently from the truck court beside it and can take an overlay while the yard takes digouts.
Questions about asphalt resurfacing
An overlay suits a lot whose surface has worn out over ground that is still carrying the load. Where cracking runs in interlocking patterns through the wheel paths, or the surface moves underfoot, the material below has failed and a new layer over it will crack the same way within a season or two.
Section by section, yes, but not all at once. Planing, paving and opening are scheduled in the same shift for each area, so the closed part of a lot moves through the work rather than the whole surface being out of use.
They do. Grinding removes them with the old surface, so the layout is measured and painted on the new asphalt, and the accessible stalls and aisles are set out to the current dimensions at that point.
A thin maintenance overlay is hot mix of 0.15 feet or less, which is a little under two inches. What a particular lot gets is a decision on site, taken with the levels at the kerbs and inlets.
Millings are loaded straight from the planer and hauled to a plant that takes them, where they are crushed for recycled base or blended back into new hot mix as reclaimed asphalt pavement.
Asphalt resurfacing by city
Resurfacing is requested through the asphalt paving page for your city, which covers the lots, permit authority and recycling there.
Related asphalt paving services
