..

Pressure washing the old concrete first may reduce the need and produce a better
match after the first time it is washed after installation. You don't want to
match the dirt on the old concrete.


be careful a buddy cleaned his concrete one summer preping to sell
home in the spring.

he raised the grain of the concrete, damaged the surface. after a hard
winter, cracked and spalled all over....

ended up replacing most of his sidewalk..

he also damaged his deck boards...... cost his a deck rebuild, which
was OK I guess some of the joists were rotting, found when the deck
was pulled up....

he gave away his pressure washer......