Fieldstone Foundation Trouble - Any "Free Mason" advice available??

dtreger

I live in a house Circa 1850's. One half of the house sits atop of a field stone foundation that is below grade - the fieldstone makes up 1/2 of the basement walls.

The mortar in the wall was dry and crumbling, so I hired the guy who rebuilt my chimney to do something about it. He advised me that most of the mortar, though dry, was stable and strong, and he just needed to smear a coat of mortar on top if it. I disagreed, and told him to be as aggressive as possible removing mortar before applying new mortar. He said he used a wire brush to remove as much mortar as necessary before applying new mortar on top.

I have found large sections where the mortar is still dry and powdery. It is stable if you touch it with your fingers, but if you poke it with a tool, you can get it out. I have removed mortar in some places that have revealed holes leading to the exterior.

The other significant issue is that in one corner where the foundation is wet, the new mortar never set, and it appears that there is soil, not mortar behind it, because large fungus began growing through the new mortar almost immediately, as well as some roots.

SO . . .

I am loath to call this guy back - I've almost would prefer to do it badly myself than get ripped off again. - my questions.

1. Should I aggressively remove crumbing mortar and repack the joints, or simply remove the surface of the crumbling mortar as my guy said, and apply new mortar on top.

2. where there are large gaps in the wall (the wall is very stable, and does not seem to be moving), should I fill those with concrete mix instead of mortar?

3. Should I attempt to dig out the soil and organic matter in the wet corner and fill it with mortar or cement, or is there a cement product that can be spread over the soil and organic matter that will neutralize/waterproof the area?

4. When I apply new mortar, how long do I need to keep in moist to allow it to cure. Should I sponge it once after it has hardened, or should I wet it and cover it with plastic to allow a slow cure?