Sealcoating FAQ
INFORMATION GUIDE FOR SEALCOATING
1. SEALCOATING NEW PAVEMENT
New parking lots are generally ready for sealcoat two years after construction – when curing is complete and the structural soundness of the lot’s surface and base are established.
2. LIFE OF FIRST SEALCOAT
Two coats of sealcoat can last as long as four years. However, various factors – traffic volume, grade of material, quality of the sand and latex – affect the life of the application; a three-year duration is probably more realistic.
3. MAINTENANCE
A number of factors determine how often a lot should be resealed. Lots with a lower quality of pavement and/or high traffic volume need to be treated more frequently but, in general, pavement should be resealed every three to four years.
4. SPRAY VS. SQUEEGEE
Spray treatments are ideal because they apply the material evenly. Squeegees are adversely affected by the pavement texture: smooth surfaces don’t “take” as much material and rough surfaces take it unevenly. However, in windy weather, squeegees are the only option.
5. ALLIGATOR CRACKS
Sealcoat does NOT waterproof “alligator” or “spiderweb” cracks (a concentration of interconnected cracks in one area). These cracks are usually indicative of structural flaws; sealcoat is a preservative measure, not a reconstruction. Ideally (and money permitting), areas with alligator cracks should be excavated and replaced with new asphalt. However, minor surface cracks can be “quick-fixed” with a rubberized hot-pour material.
6. SEALCOATING SEVERELY CRACKED AND ERODED PAVEMENT
This is a common – and costly – mistake. Seal coating old, eroded pavement will NOT extend its life cycle. It will not plug leaks to the base layer. As a cosmetic fix, it’s about as effective as covering facial wrinkles with candle wax. Don’t waste money seal coating a decrepit lot; save it for repairs and an eventual overlay of new asphalt.
7. DRY TIME
The more coats used, the longer it will take to dry. Weather is also an important factor. In general, though, sealcoat is dry enough to be walked or driven on after twenty-four hours.
8. SEALCOAT ON SHOES OR TIRES
If walked or driven on before it dries, sealcoat will “track” to shoes and tires and can get messy. However, before work commences, each section of the parking lot is cordoned off from the public and clearly identified with flashing barricades and traffic tape.
9. CORDONING OFF SECTIONS OF PARKING LOT
With strategic planning and effective communication, the disruption and inconvenience caused by sealcoating work can be minimized. Everyone affected is kept informed. Barricades are strategically placed so that traffic flows smoothly through the lot at all times. Property managers and their tenants are kept up-to-date on the schedule. And the schedule for every project is custom-tailored to fit the unique needs of the property.
Work areas are ALWAYS clearly delineated with flashing barricades and yellow traffic tape.
10. TIRE MARKS IN NEW SEALCOAT
In the weeks immediately following a treatment, tires may leave marks in sealcoat – but this is nothing to worry about. Though the material dries in a matter of hours, it doesn’t fully harden for several weeks and, during this time, small amounts of sand may be dislodged from the mixture. The resultant marks will vanish in a short amount of time.
11. THE IMPORTANCE OF SAND
Sand extends the life of the material. It also makes the sealant less slippery. But it can’t be any sand: only a certain particle size may be used. For a proper mixture, each gallon of concentrated coal tar requires three to five pounds of sand.
12. THE IMPORTANCE OF LATEX ADDITIVE
Scrub tests indicate that cold latex, added to Federal Specification coal tar, extends the life of the sealant. (It strengthens the bond between coal tar particles.) This effect can’t be precisely measured, however, because dilution rates vary in the batching process.
13. MIXING WATER WITH CONCENTRATED COAL TAR EMULSIONS
Emulsions vary in quality and manufacturers have different recommendations. Mixtures range from 10 to 40 per cent.