On Friday, September 18, 2009 4:13:47 PM UTC+1, Steve wrote:
'Non-setting mastic' is sometimes recommended for pointing ridge tiles as an alternative to sand/cement, to allow for slight movement.. However, I don't know where to find it - the only non-setting mastic I can find is Plumbers' Mate - obviously unsuitable!There are plenty of low modulus building mastics but they are not 'non-setting'. Can anyone suggest where I can get a suitable non-setting mastic?Thanks

It comes in a plastic bag and it looks like a mass of small white polystyrene balls the size of pin heads mixed with some form of pink adhesive, texture is like putty density or similar to plasterseen. It never took on to expensive and not very practical.
Never seen it use and when asked at the merchants if they had sold any they just laughed.