Basement waterproofing - which way to go

Hey everyone,

We bought a house and ended up getting a bit of unexpected project at our hands. To make long story short. Shortly after taking the possession of the house we found cracks in the foundation (quite many) that were hidden behind tons of stuff that the previous owner had.

When we inspected the house, we saw efflorescence and we knew that it will need work, it just appears that there is going to be more work

Anyway,
so the house is 49 years old and it sits on the block foundation. The back wall has a bunch of horizontal cracks and is bowed at about 1/4 inch in a couple of places. There is no real water in the basement but there is a lot of efflorescence on the block at the footing and on the floor. There is not efflorescence above the footing.









Unfortunately, only one wall in the basement is not finished, so we don't know what is going on with the rest of the foundation yet.

To make things worse, the foundation is covered with the polystyrene boards on the inside and together with the moisture they create a fantastic environment for mold




I called a structural engineer who told me that the issue we have is due to the high water table as it's common in this neighborhood. Our house sits higher than the land around it. We have a sump pump but the sump pump pit stays dry even after the long and heavy rains.




It appears that we probably don't have French drain as I don't see any piping coming to the sump pump.

The proposed solution is to excavate the foundation ~ 7-8 ft deep, put a membrane and install French drain. Unfortunately, the quote hurts - we got $60k quote to do this. (We live in Canada). It's a bungalow with the large footprint and on top of that, our porch is made out of the concrete slab that needs to be broken for the workers to be able to get to the foundation and bumps the cost.

I am interested to know if we can get away with internal weeping tile. I plan on removing the drywall and polystyrene boards in the basement to find out what we got but it might be the case that we are only getting the water from underneath, so putting the drain internally under the slab should do the job.

As for the wall cracks, we have a stone patio recently installed by the previous owner and the installation was done improperly. And it might be contributing to the cracking of the back walls. We'll take it apart and rebuild it maintaining the proper grading. Also the previous owner let the gutters completely dirty to the point that the gutters got plants growing inside, so the rain water didn't go away properly.

We cleaned the gutters, we'll regrade the land on the back but my main question is whether internal weeping tile under the footing would be a good solution. It's significantly cheaper than external solution, especially if I add the cost to rebuild the landscaping in front of the house to the $60k project.

If anyone has similar experience, please share!

Thank you so much!

I've attached a few photos around the house:

 

You speak about waterproofing the basement yet I don't see anything in your post that states an actual water problem.

Your sump pit is dry, efference is water vapor escaping, not water, the cracks are not leaking water so why the jump to the high cost solution before completing all the simple low cost fixes like gutters and grading to see what they have done to improve the situation?

 

Your basement looks good to me. My understanding of efflorescence is that it normal and not necessarily indicative of a problem. The cracks in the wall look clean and not leaking.
The only concern I'd have with your situation is moisture level. I'd put a crawl space dehumidifier in there and set it to 51%.

 

While none of your pictures show obvious signs of serious water problems. Water is best kept outside the home. That means that any treatment is best done on the outside of your basement walls. Obviously this means digging so it's generally a pretty major job with a price tag to match.

I tend to think of basements like boats. If the hull has some leaks the proper fix is pull the boat out of the water and repair the hull from the outside (excavate & waterproof outside). The cheaper sorta temporary fix is bigger bilge pumps (interior treatments). One prevents the water from ever entering the envelop of the home while the other only deals with the water after it's inside.

 

FWIW, water PROOFING is done outside the home with gutters, downspout extensions, grading, .... Anything done on the inside is water MITIGATION.