Induni Conservation Ltd. Registered in England, No.:6124875

Dr. Bruce Induni,  consultant on stone and mortar

07971 194454 : induni_conservation@yahoo.co.uk

 

Pitstone font : Understanding materials

The most difficult part of the repair at Pitstone was determining the cause of the problem. Close examination of the extent of expansion damage eventually ruled out all possibilities except mortar expansion. This is not unknown where gypsum has been used as a retardant in Roman cement based mortars.

 

The problem is an excellent example of how background knowledge of historic materials is a vital tool for solving conservation problems.

 

The font as whole is an excellent example of how most stone structures are really composites. The font is (or was) built with a combination of stone, wood, metal, mortar and adhesive. Successful conservation usually depends not only on understanding all these materials, but also on being able to predict their presence.

The font stripped of all its loose and broken fragments. The reddish stain is caused by shellac used as a adhesive in earlier repairs. The black mortar at the foot of the font is Roman cement.