Question for Worthy on Seattle 1920's Basement Waterproofing
I have thoroughly enjoyed reading and researching all the prior posts on this question of which system to go with- interior vs exterior waterproofing and it seems quite clear to me that exterior waterproofing is the clear winner in terms of actual "water-proofing".
The biggest disadvantage of course is cost so that is why I am even remotely considering an interior system as an option. I have a couple of questions for Worthy and for others.
I have a 1920's Seattle home that has poured concrete foundation walls. The east wall of the basement tends to have water leaking through the walls about 4 feet from the floor. I can see salt marks left over. Last winter after a terrible thunderstorm (more than usual for Seattle), our basement literally flooded with 5 inches of water. The East wall also has a Landscape Grade problem- The backyard SLOPES down towards the East wall. Additionally, our neighbor's garage does not have any gutters and all that rain literally just falls right into our lawn and down the slope. The slope differential height is about 18 inches. We have gutters that all drain into the main sewer line and have been inspected recently.
Would Re-Sloping the backyard and doing proper drainage planning be sufficient to avoid any exterior drainage system? Is it worth it to do this first and wait and see what happens before investing into an expensive exterior system?
Does an exterior waterproofing retrofit properly done prevent water from seeping up from the floor (assuming no cracks in the floor foundation)? If not, would an interior waterproofing system prevent water from seeping up from the floor?
On the East wall, the wall/floor junction is not a straight 90 degree angle but curved. One of the bidders told me that this may be a "monolithic" pour. If so, wouldn't it be a bad idea to cut through the concrete floor to install an interior french drain system since it may compromise the structural integrity of the foundation system?
Is it common for homes built in the 1920's to have Concrete footers that were poured separately from the walls and floors? Does it matter when choosing between an exterior vs internal system?
Is it legal to drain the sump-pump into my sewer line (where my rain gutters also tie into)?
I'm leaning towards an exterior system but the cost is killing me. One guy gave me an estimate that was the cost of a new honda civic. It blew me away. Another guy however gave me an estimate for an exterior system for the cost of a used 2003 honda civic. Makes me wonder and very frustrated.
Thanks for any tips and sorry for the long post!