mortar disintegrating in church walls

wombosi

hi all.
i've been asked by a church around the corner to come in and make a repair, but there is a larger problem going on.

the church was built in the mid 1800s and has various additions. the walls are solid structural block about 2' thick.

in the basement room i looked at, there are 2X4s on the flat carrying drywall. these are newer studs, probably done 40 years ago.

anyway, what's happening is mortar is crumbling and accumulating in large piles at the bottom of the walls, and blowing apart the drywall that's there.
this is happening in various areas all over the church.

there is another church in town apparently built in the same period, with the same stone, presumably by the same masons, and it has recently been condemned and will be torn down because of massive structural issues with the stone falling apart.

here are some pics:
outside:


other side of wall:




my thinking is that basically nothing can be done about this unless they gut the entire church and remortar everything.
i think the best bet is to clean up the stuff, and patch the wall.
maybe stop the drywall short of the floor and put in a removable baseboard. or use a piece of plywood instead of drywall.
at some point someone installed those two "panels," which originally had a wire grille, and someone had covered it up.

a baseboard heater has been removed along this wall. i'm not sure what the design reason of the panels was, but they're underneath the windows, and in my mind serve as neither cleanouts no ventilation.

should i be looking at installing some sort of plastic behind whatever i use to patch? or maybe use durock? or build some sort of hinged panel so at least they can clean it out periodically?

patching is pretty straightforward. i just want to be sure about the bigger picture of what is going on and whether there is more i can do about it or not.

thanks guys.

Tscarborough

It is a common problem and the fix is pretty easy, although not cheap. Google "historical masonry repairs" and "lime mortars".

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