I have spalding of sandstone walls in my basement and was wondering how to identify if the parging is old lime based or was portland cement added later.
The basement was painted so I'm thinking the spalding was caused by moisture trapped by the paint. My wife thinks the parging is lime mortar because it crumbles and looks like very rough agregrate sand was used.
If the old parging is lime based I plan on repairing with lime mortar. If the parging is cement than it will have to removed.
Anyone out there have an answer?
Last edited by Fishdaddy; 08-26-2010 at 10:49 AM.
its ' spalling ' & the cause is usually moisture penetrating the sandstone - even if granite had been used for walls, water/water vapor would still have penetrated,,, there wouldn't have been any significant spalling as the granite is strong enough to resist the damaging effects.
my suggestion's to remove the coating & let the walls breathe but we only do this work for a living