[MassHistPres] Cleaning Sandstone

[Brian Badrigian]

We are trying to clean the sandstone window jambs, sills, headers and water tables on a granite gothic style church which is 100 years old.  The building is on a corner and is close to 2 busy streets and hence it has accumulated a lot of exhaust emissions and street dirt.  I would appreciate some advice about cleaning products and methods and/or who may be contacted as an expert in stone cleaning and restoration.

Thank you for your time with my request.

Brian Badrigian