NEW: How to use polyurethane expanding foam to fill gaps and cracks

Expanding foam

Some gaps and cracks are , well, crackers. Too big for the standard gap-filling materials of gap filler rod and caulk.

They need something that will do the job without wasting your time (and lots of products).

Polyurethane expanding foam is the answer. It comes in an aerosol can and sprays on through a nozzle-tube expanding to fill the gap. It cures to a hard foam which can then be cut back, sanded and painted to look real nice.

It can also be left to look like you've just filled gaps with a a solid whipped cream. (I've done that in this GIY video as it's hidden behind a dishwasher.)

I know it's not the 'greenest' product on the market but in small amounts it's better that a draught. You could use old socks if you really wanted to.

It's easy to use but there are lots of great tips in this video on how to do it with minimum fuss.

Trickiness rating: Easy

Stickiness rating: Very (but managable with nail-polish remover or acetone)