After an extension, my driveway's still got bits of dried cement on it.

hi if you go to any decent hardware shop you can get some cement remover ..easy to apply it will desolve the cement and make it easy to clean off ...good luck

wash it down scrub with some brick cleaner or acid with a hard brush then wash again or just jet wash. if you do use the acid wear some decent rubber gloves

Scrap off the big bits with a shovel, then you can use brick acid to remove stains. Follow instructions on acid container, as this stuff will burn your skin.then wash down with plenty of water. Alex Driscoll Driscoll brothers brickwork

Really it should be down to your builder to put right. You could try a mild brick cleaner / patio cleaner, follow instructions, or you can get tarmac paint, again ty a test piece first.