Sealcoating
How many coats of sealer does a driveway need?
A bare or gray driveway takes a second coat, because the first one soaks in rather than leaving a film, and a surface still holding color does not.
The numbers
- Bare, gray or newly repaired asphalt takes a second coat.
- A surface still holding color from the last cycle takes a single coat.
- The second coat goes on after the first has dried, not on top of a wet one.
- Stacking extra coats is not better. A thick film cracks on its own.
- Black Widow Sealcoating publishes what goes down: two coats where it needs two.
Why the second coat is the one that seals
The first coat soaks into the top of the asphalt and fills the open texture. It does not leave an even film, because it is busy filling. The second coat has something smooth to sit on, so it lays down as a continuous layer, which is the part that is doing the work of shedding water.
A single coat on a gray, thirsty surface looks black for a while and then goes patchy where it soaked in unevenly.
When a single coat is the right call
A driveway sealed inside its last cycle that still has color in it has most of a film left. A single coat tops it up. Stacking a full second coat on top of that leaves film with nowhere to go, and thick sealer cracks in a fine pattern the first hard winter.
The high traffic areas are the exception on any drive. The apron at the road and the spot a car sits in wear first, and those areas often take a second pass even when the rest does not.
What a coat cannot do
No number of coats fills a crack. Sealer bridges nothing. Anything wide enough to take water gets hot rubber crack filler first, and then the coats go over the repaired surface.
Coats do not level anything either. A driveway with a low spot that holds water after a rain has the same low spot afterward, and so does a surface that has raveled rough. Sealer follows the shape it is spread on.
One more thing worth knowing when you are comparing quotes: coverage is what decides how much material a drive takes, and a rough oxidized surface drinks noticeably more than a smooth one. Two drives of the same square footage are not always the same amount of sealer, which is why the condition gets looked at before a number gets given.