I have an old house in Montreal, close to an old quarry. Back then, building code did not require putting gravel under the slab. There is not sump pit or french drain.
I have a finished basement with an equipment room (that wasn,t renovated and that I don't care aboutthe looks of) where I'd like to install a sump pit + sump pump. It's right next to my fron yard. On the opposite side of the basement, next to my backyard, is a bathroom where I had a tiny bit of water coming from the floor after torrential rains. I also have access to a trap in the middle of the basement that alloes me to see the concrete slab, there was some water there too after heavy rain, not much, but still some water, it wasn't just humid.
The house is pretty small, it's a victory house/ post ww2 house. Thanks to the proximity to the quarry, they may have put a small but rather unequal amount of gravel under the slab, but nowhere near enough to allow good draining like a modern house (4-6'' thick). The soil is most likely made of glacial till (aka clay that doesn't drain) on top of a bedrock of limestone. I am hoping we can reach the limestone as we dig the clay. It'll be done by basement professionnals, I am terrible at DIY.
Would that sump pit+pump help or be mostly usless? Would water drain between the clay/gacial till it reaches the sump pit?
6k$ was quoted for a sealed sump pit+battery backup pumps which seems somewhat reasonable, 15-20k for a french drain system or interior drain one is out of our budget even though that would solve the problem for sure.
Some things I read say it's pointless, others that it might work, or it may not, including our new AI overlords, finally, some posts of homeowners with similar basements on reddit suggest it may help and be worth it. I am at a lost.