Sealcoating
How many coats of sealer does a driveway need?
Two coats is the normal answer on a driveway, and one coat is enough on a surface that was sealed two or three years ago and has held up.
The numbers
- Two coats on bare, gray or newly repaired asphalt.
- One coat on a surface still holding color from the last cycle.
- The second coat goes on after the first has dried, not on top of a wet one.
- More than two coats is not better. A thick film cracks on its own.
Why two is the usual number
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.
One coat on a gray, thirsty surface looks black for a month and then goes patchy where it soaked in unevenly.
When one coat is the right call
A driveway sealed two or three years ago that still has color in it has most of a film left. A single coat tops it up. Putting two on it stacks film that has 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.