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Installing a sump pump

My question is regarding how usefull a sump pump installation would be regarding the situation below.

A crack in the wall has been epoxied, and the entire wall has had a "tar membrane" according to the previous owner. The guttering, downspouts, and grade are all good to go, but with a couple weekends of steady rain, we still get water in our finished basement. Curiously, the previous owner said he never had leak/water problems in the basement... hmmmmm.... anyways....

We would only have the pit dug, the sump pump installed, and the outgoing water will be sent to the downspout outside.

Would this be a waste of time/money if we don't dig around the house to pipe in water from the sides of the walls? Would the sump pump help relieve the water pressure from the sides of the walls, and the same for future rains? Or would it still come in through the wall/floor joint since the sump pump would only be for what is below the floor? The basement wall is cinder block.


Timothy Miller
Re: Installing a sump pump

Howdy where do you see the water coming in threw the crack in the wall? If there is one isolated area that the floor gets wet then breaking threw the slab and installing a pump pit and pump might resolve the problem. If a general water to the floor then breaking out along the wall and installing a peripheral drain and pump pit and pump would be needed.

Re: Installing a sump pump

I'm not sure whether or not the water is ocming through the wall, the floor, or the joint between the floor and the wall.

This may sound like a stupid question, but I have an area that I wouldn't mind if I made a hole in the drywall. When people finish a basement, do they typically leave enough room between the frame, and the basement wall, to take a peak through a hole in the drywall to check out any leaks? Or is the wood frame typically flush against the basement wall (providing no room to take a look at the leak)?

Re: Installing a sump pump

The ideal here is to install a sump pump with proper drainage to collect all the water around the foundation walls and divert it properly to the sump pit.
Other than that, even if you install the sump pump in the lowest corner you will be relying of the gravity and at the mercy of whatever terrain conditions are already in place.

Thus, I'd suggest that you look into internal perimeter drainage systems, assuming that, you have already external drain tiles which were probably installed when the tar membrane was applied, and the drain tiles are failing, as they usually do overtime.

Internal drainage systems can be installed with less mess and disruptions than replacing the french drain, for a fraction of the cost and they do a great job in relieving the hydrostatic pressure. Thy are also serviceable throughout the years, so that you will never have to dig them out again.

If you are going through the expense of installing a sump pump you might as well add the drainage system and get the basement dry once and for all.

It is also quite possible that the previous homeowners did not experience any problems. Tar membranes are usually not called waterproof, but damp proof because they are usually not completely impervious to water, and studies show that they tend to deteriorate overtime. So that might just be the case with your home.

Re: Installing a sump pump

The above method is the cheapest method but isn't the best way.
We have block foundation walls and had the exterior of the foundation dug down to the footings. Perimeter drains were replaced and the walls were patched and covered with a waterproof coating. Overtop of the waterproof coating a drain membrane was installed before backfilling. The perimeter drains run into a sump pit and pumped outside.
We chose this method after reading up here on the forum and it works great. Yes, it was expensive but our basement is perfectly dry and we noticed less problems with any cracking or shifting with the foundation.

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