Can you recommend a product to deal with a cracked windowsill?

Brummer Green Label is what you need. It’s our waterproof exterior grade Filler and is an excellent product for filling smaller cracks and holes in outside woodwork e.g. windowsills, doors and garden furniture.

It doesn’t require weatherproofing, won’t shrink or crack and works equally well with concrete, plaster, fibreglass and stonework so it’s a very versatile tool for any number of outside jobs.

It should not be used where the wood is rotten however and is not intended for larger faults or splits. For these jobs we recommend Brummer 2 Part Wood Filler.