basement issues...

Steve_DIY

Before I begin my story I would like to thank everyone ahead of time as I am a new user but have browsed DIYChatroom many times as a nonregistered user. Your wealth of information has been useful more times than I can count since I purchased my home

My question concerns the house I purchased around 18 months ago. The previous owner had heaving walls in the attached garage of my cape cod style home. Before my wife and I moved in, an interior French drain with a sump pump was installed in the garage along with 4 wall anchors in the wall that was heaving. I am guessing they didn't want to spring for full excavation and waterproof/drain tile installation of said wall.

When I moved in, I noticed that the downspouts were still tied into the original 50's style terracotta drain that ran along the foundation of homes like mine. I guessed that this may have caused the water issues with the wall as one of the downspouts led right into the corner of the problem wall. I disconnected the downspouts and ran them around 5 feet from the house downhill so water penetration should not be an issue from the downspouts.

I now come to my problem. Above the interior French drain along the basement wall we have started to grow mold. It seems to limit itself to around 2 to 3 feet above the drain tile itself. It is most noticeable above the sump pump in the corner. In heavy rains I check and there is no water penetration through the wall itself. But there is definitely water penetration through the foundation as the pump runs on about 45 minute cycles in heavy rains and melting in the spring.

Now I assume that when the interior French drain was installed, there were holes drilled in the base of the block wall to allow water to enter the drain tile and out of the block itself. I have not verified this with the company but from what I know of these types of installations, that is common practice. I have removed sump pump and pit and cleaned them thinking this have caused the mold issue but to no avail. The relative humidity in the garage typically does not rise about 50%; it averages around 40% and lower. Now since I have dry walls, no water in the block, and a pump that is working in a low humidity environment, where in the sam hell is this moisture coming from!?

My residential contractor friends have said the only way to fix it for sure is to excavate and properly seal the foundation along with installing a proper exterior French drain. With the wall anchors already there I know this will be an issue that I would rather not tackle myself. If I can remedy the water issue I know the wall would be ok as it has almost been pulled plumb over the last 18 months.

In any respect I was hoping anyone had thoughts with my issue. Thank you ahead of time and I hope to become a helpful member of the DIYChatroom family. Cheers!

Steve_DIY

I suppose I answered part of my question when I asked where the water is coming from. Obviously the moisture is from the interior drain tile itself. My curiosity is in the fact that even though water is being removed there is still a real moisture issue even with the system running properly. If all the interior French drain systems bred mold growth, then they wouldn't be so commonplace. I've seen many of these systems installed without any issues whatsoever. Why do you guys think that mine is contributing to mold on the walls?

Sorry for the confusion. Any thoughts, comments, or questions are appreciated.

Cheers!

jomama45

I can only guess, but I wouldn't be suprised if the holes weren't drilled, aren't effective, etc....

When drilling each core at the base of the wall, it's imperitive to also drill a whole higher up in the wall (usually in a bed joint, about 4-6 courses from the floor) and flush water through the upper holeto ensure that the weeps actually function. Mortar damming on the footing can be a large problem on concrete block foundation walls, and a few different methods evolved through the years to address at construction. The fact remains, if there's a few inches of excess mortar dropping over the footing, water will never be able to weep through to the holes........

Steve_DIY

Thank you for the reply! Looks like I will be drilling to verify that the weep holes exist/are working. If I have to take out the whole drain and redo it myself I will not be a happy camper. I will keep you posted...