“Where a preservationist might insist that broad expanses of decayed original plaster be repaired or restored with new material mixed and applied according to traditional recipes and finishes, a renovator would more than likely remove the plaster entirely, replacing it with modern materials that would more or less duplicate the original texture”. With one, long, sentence, George Nash* explains the challenge of old homes.
When you’re trying to save them from water damage and make houses comfortable, energy efficient and healthy for our modern times you have to understand the materials that are there, and how they behave. A section of board sheathing replaced with modern OSB can change the drying behavior of a wall in a big way. Add a rubble foundation with a heavy moisture load, and probably radon, and you can turn a house into a nightmare quickly.
With an older home you have to think about source control of water and air as the basic elements of moving a building into the future. If we don’t get the basics right we will lose many of our wonderful older buildings to our own thoughtlessness.
* Renovating Old Homes by George Nash. Published 1992 by The Taunton Press