Published on February 20th, 2015 | by Henri0
Waterproofing of basement attracts centipedes
Q. I live in central New Jersey and had a water problem in my basement. I had a waterproofing company install the type of system where they jackhammer out the concrete along the walls, pierce the foundation block to let the water out, create a pitched trench, use blue stone as a base, and perforated pipe on top of that to catch the water, add a plastic sheet on the wall which goes into the trench and fill the trench with concrete.
The pitched trench leads to a sump pump in the corner and the water is pumped to the outside. The system works fine and we have not had any water problems since. However, we do have something else, which I am not so sure is worth the trade-off of the water.
Since the system was put in, we see centipedes in the basement and some of them make their way to my first-floor kitchen and occasionally to my second floor. These centipedes are extremely unnerving to me. They are about 2 inches, sometimes 3 inches in length, with a thick body, lots of legs and move quite rapidly.
I feel very certain that they are coming from the area of the sump pump, which has a cover, or perhaps up the wall of the trench behind the hard plastic piece. We have pets, so I am hesitant about using an exterminator, although I’m not sure even that will help.
Please let me know your suggestions. These creatures have made living in my home much more unpleasant than the water in the basement.
A. Centipedes are fond of damp areas. It follows that when the plastic was applied to the walls, it created a damp environment between the plastic and the foundation. I have always questioned the use of lining foundation walls with plastic sheets for that very reason. It is fine to dig a trench in the concrete along the walls and install a drain leading to a sump pump, but why bother with the plastic?
Although I always warn against waterproofing block walls, it is OK if there is a way for the blocks to drain, as they would with the system you had installed. Waterproofing the block walls would not have created the damp environment the plastic lining provides.
To control the centipedes, you have the choice of using residual sprays better applied by a pest management professional who will know where it will be most effective, or drying the basement by removing the plastic, something you may be reluctant to do, understandably, considering what you paid for it. Keep in mind that the best control for many predator insects is the removal of their food supply found in damp environments.by