The addition my friend had put on has caused even worse basement flooding problems than ever. It's perpendicular to the old foundation and the sloppy backfill, poor exterior foundation waterproofing, and less than ideal grading has caused rainwater to find its way into the little 15 x 15 basement. I just barely saved the basement from Irene. The walls are block, prolly 60 years old. In the past , I painted the floor dark grey then light grey as you can see.
I think if this basement floor is like the sidewalks somebody put around the property, they're very thin. Maybe 2" on top of rubble.
During the record rain, I saw water under hydraulic pressure literally geysering up out of cracks in the basement floor, and I could see the groundwater table by where water was running in through small cracks in the block walls! It started at 23" above the floor. And this was the block wall I had just put 2 coats of UGL drylok on. I've seen UGL Drylok fail more than once. I'm trying to keep the cost down on this and now that the walls are drying out, I want to put like 5 coats of Drylok on the walls.
There is a sump pit, it saved us this time, but only because we were browned out for most of Irene. The sump pump continuously operated.
Anyway, I went down there today and was seeing if I could scrape off any of the old loose floor paint (latex). I ran my Alto sander into a corner and didn't see it still had water standing there!
Mopped it all up and now drying my machine bottom and the floor.
I want to use a 2 part epoxy basement floor paint. I see there are a lot of industrial epoxy floor coating places out there, but way expensive- like $750 to do this 225 sq./ft. I think there are some flexible rubber-like waterproofing products out there too.
Also thought of skim-coating the floor with sand-mix, but I think the cracks would just come through. To top off the problem, parts of the floor are soaked in 40 years of fuel oil drips from the tank that used to be there...
also thought of West System epoxy and fiberglass cloth. I think I have enough cloth, but the epoxy is mad expensive, and if I fiberglass the floor, I wonder if hydraulic pressure would break its bond and push up the fiberglass job, unless I made it boat-hull thick, again, mad expensive.
I did a 4 car garage once with Griot's Garage floor epoxy, it came out thick and very durable. Expensive though.
Just lookin for feedback; I want to rest easy the next time the water table comes up.