Chris Plastow
This is more difficult than one would expect. If you want a proper job done , you must use sand and cement . Tiny quantities are unavailanle from hardware shops as far as I know , do not buy 'filler'. Your local builder might like to give you half a bucket full, ready mixed . A small quantity of wet cement should placed on a postcard sized plate that you can hold against the wall at the hole level. Using a broomstick shaped tool, this can be anything you can find that will easily fit down the hole, push some cement into the hole , right down to the back and repeat until the hole is tightly full . Allow to dry for a week before drilling into. The main trick is the wetness of the cement, add water slowly until it is like thick cream .
