I have a question about older foundations. I have a 1915 house in Boston with a rubble stone foundation. In the basement, the foundation is parged (like stucco) with …. what? mortar? There are large areas where the material is disintegrating. I want to remove it and re-parge it. What is the best material to use? Thanks
I'd use a sand-lime-portland mix. By volume, something like: Six parts fine sand, one-and-a-half parts hydrated lime (agricultural lime is fine for this), one part portland cement. Knock all the loose parging off, and wet the wall so that it is damp before parging. The high lime content will make the mix easy to work with, as it will adhere very well to the wall (with little slumping or weeping).
Actually, I'd probably use more lime and less portland. For above-grade work, I don't use any portland at all ... just 3 parts sand to one part hydrated lime as mortar for stone masonry. A light spray of water (before the mortar sets) exposes the aggregate, and looks very lovely. Tinting the lime and matching the original sand for color and coarseness makes it possible to exactly match any old (pre-Civil War) mortar. The downside to lime mortar is the long "setting" time. It may take a day before you can add another course of stone ... and months before it reaches its maximum strength. On the plus side, you can mix a job's entire volume of mortar at once, and as long as it's kept moist and covered, it will stay workable. I've used a single batch of "pre-mixed" mortar over the span of a couple years.
Also check the recent "stucco" thread in the constuction techniques area. Stucco is basically what you're applying, and some the responses are applicable to your situation.
If you care about your lungs and life and you are doing repair too, good chance you will run into asbestos in the mortar
yeah maybe they didnt in the year your house was built, but maybe, and definatelywhen any repairs or re-sealing or re-ticking was done
masks, fans etc.....what ever , even if no questin keep it clean
my bro and I grew up in DC and are 3rd generation builders ( and we both have 4th generation behind us) actually 5 of us grew up the re only 2 of us sticked with dads trade
luckily, why, my dad was alwyas protective and we wore dust masks just to keep sh&t out of our lungs, maybe because his bro was a black rocker (coaler', black man, coal man in W.VA to you city slickers) and he saw what dust and carp did to lungs long before cancer was a concern
but If you are going to do any repair etc, please protect yourself
Good advice to use dust masks, but silicosis is more likely from masonry than asbestosis is.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
remove anything loose... tap it with a hammer if it sounds off it is... i've seen and read on alot of "self leveling products" never used any but it might be a choice... or if you have the inches to spare... maybe insulate 1/2 foam board... vapor barrier, and cap with 1.5" to 2" fiber concrete... maybe score & stain it and you have a finished floor...