When I say " Historic", that usually means homes built 1920 or before. But some of this applies to any stone home. Recently a lady asked about stopping water that runs into her stone cellar when it rains hard. She wanted to stop the leaks. The general contractor who claimed to have knowledge of historic restoration actually doesn't have that knowledge, or just doesn't care.
We have many homes like this in Loudoun county VA. Stone cellars with dirt floors. A bricklayer I know met with the contractor, then called me later to explain what the lady wanted done. He had advised her to parge the stone with portland cement, then the contractor was going to pour a concrete floor.
I explained to him why parging with portland cement was the worse thing you could do. In short, that will create water to build up behing the wall, which causes pressure against the wall, which can eventually cause the wall to bulge out into the cellar. It can also cause mold, mildew, must, smell, and rot. Where do they think the water is going to go?
Bricklayer runs that by contractor, and he says not to worry about it, just give him an estimate on parging. What, don't worry about possibly seriously damaging someones house with improper repairs?
Anyway, some basic do's and don'ts of stone masonry are: (1) If you need stone work or repair, Do hire an experienced stone mason. (2) Do consider installing a chimney top damper (3) Don't use portland cement to parge or point up stone (4) Don't do what you see a homeowner did in bottom right photo. He had a laborer basically smear type S mortar overtop of what appeared to be good lime mortar joints. The white lime mortar with larger sand is good, the gray mortar that is smeared over the lime mortar and stone is bad. (5) Don't have anyone parge the interior of your stone cellar or basement. Ask yourself where the water is going to go? This causes all kinds of problems over time. (6) Don't hire a bricklayer that doesn't have experience in stone restoration and preservation, and lime mortars. Lime mortars and stone work together to allow walls to breathe, and water to penetrate, escape, and evaporate. It also allows some walls to move which is normal in many historic buildings.
Jeff Pearl / Lic in VA
Remax Distinctive - Reston VA
703-727-4876
Homes / Land / Farms / Historic
www.jeffpearlhomes.com
Equal Housing Opportunity Provider
Comments(9)