I have my two A/C units sitting on a 8ftx4ft concrete slab. Unfortunately it is sitting up against the house and pitched towards it. The slab is also higher than the basement foundation wall so when it rains my basement gets wet. I need some recommendations on what to do.


1. I can get it mudjacked which costs about $800.
2. I can get it sealed with an external membrane which will costs around $1500. This involves removing one of the A/C units, removing the house trim, and breaking up some of the concrete slab so they can excavate to seal the where the basement wall meets the bottom of the house.
3. Put a small trench in the concrete in the shape of a "T". One line will be parallel to the house and the other trench will be pitched away from the house into the lawn. Not sure how much this will cost.
4. Dig under the concrete and remove some of the dirt to try to pitch it away from the house.

Any other suggestions or recommendations would be appreciated.

Thanks,

Doug

 

I was part of a crew when we did a waterproofing job with an AC unit on a slab. After an AC worker removed the unit, we dug 8 feet down to the footing & sealed the foundation. We didn't have to break the slab at all. We dug under it. You can support it w/ wood, if needed At the same time you can remove some dirt to drop the slab & correct the pitch.

 

Posting a picture may help come up with more ideas.

Those units were suppost to installed out behind the drip line of the roof.

 

Here is a pic of the setup. The leak is coming over the top of the basement wall so it would be right next to the concrete slab which probably would still require part of it to be removed so we could see the crack. I'm thinking about removing the dirt underneath the slab to try to pitch it away from the house but I'm not sure if I'll be able to tilt the slab away from the house.

 

In your case, you could try to remove some dirt on the outside of the units. Let the slab drop a little. Seal the slab where it meets the house, with an exterior calking. Also, check the rain gutters & downspouts. Are they in good shape or clogged? In fact, do that first.

 

The water is coming over the top of the basement wall? The top of the wall should be above ground level. And if so, I don't think the water is coming from run off from those slabs, which are on ground level.

 

Unless I am mistaken, I see some sort of metal or flashing that was put in before the slabs were poured. It looks like it picks up the runoff from the siding and any splashing. The water then could run behind the metal and could leak in at the top of the concrete foundation.

Dick