Pointing Mastic is specially formulated sand. When mixed with double boiled linseed oil it creates a thick putty used for joints between timber window and door frames and masonry or render.
Pointing Mastic hardens slowly, but remains sufficiently flexible to absorb differential movement between the two materials. Adheres well to most surfaces and does not require painting.
If you need to paint it should only be done with a linseed oil based paint.
It has been used traditionally in various forms for more than 200 years.
Covers an area of approx 12.5 m per 1 kg (assuming a 9 mm joint).
Mix with double boiled linseed oil – 2.5 litres per 25 kg bag of mastic sand. Add oil a little at a time mixing until the mastic is worked in to a thick putty.
was last modified: January 20th, 2020 by Admin