Works very well. Took a few moments for me to get the hang of working with the spray, but once applied it seems to insulate against the draft that formerly worked its way into our basement. Wore disposable gloves as recommended, so cleanup was not an issue. Would be a little hesitant to use in a situation where it would be visible, say, in a room within the house, as it is not elegant in appearance. But it's quick and is not expensive.