My flat -part of a converted Victorian house- has "stone" external window cills. I have removed the old paint but the surface needs making good before repainting. What is the best method of doing this ? Are cement products likely to crack and flake off ? Would two part cellulose filler be a better bet? It looks as if someone ( probably long dead ) has used putty to give a smooth surface. I wasn't impressed with this solution either.

colin, September 2008

Use a hydraulic lime window sill repair kit (colour matched) and then you won't have to paint it.

R Dale, April 2012

You would be far better to use a colour matched hydraulic lime repair mortar which is the ideal repair material for natural stone. Instead of painting you could use a dilute version of the coloured repair mortar to lime wash your cills which will leave a far better and more original finish. If you need expert free advice on stonework visit www.sandstonerepairs.com

L Henderson, September 2010

if there is large damaged areas you need to fill these with sand and cement but first apply a coat of pva glue like uni bond straight from the tin to the area fill with soft sand and cement a 5 parts sand 1 part cement once this has set you can cover the whole cill, paint on pva mixed with water 3 to 1 let dry for an hour and rub on your cement mix with a piece of wood in a circular motion once dry it can be painted

john cavill, October 2008

an expoxy mortar filler would do you well or you could use sand and cement with pva glue but you'll need to prime the stone first with some pva glue and water and allow to dry before applying the sand cement pva mix

a s r, September 2008

BETTER GOING TO A BUILDER MERCHANTS AND THEY WILL HAVE THE BEST FILLER THAT YOU NEED JUST ASK THEM THERE ARE NEW PRODUCTS COMING OUT ALL THE TIME .I DONT THINK 2 PACK CELLULOSE FILLER WOULD DO IT WOULD NOT ADHERE PROPERLY TO THE CILL

ALEX FALKIK, September 2008