Solid Foundations

There have been several occasions in my 20+ years of service plumbing that I have found water leaks from an unexpected source. I was on a call in Bremerton during the end of a 5-day rain. I went to a house with a daylight basement that said the drain line for the washing machine was baking up. When I got there the basement floor was covered in water several inches deep. I cabled the drain in front of the washing machine and got it clear. As the water began to drain away, I noticed that there was still water coming in and flowing to the drain. I searched for the source and found water flowing past the bottom of the foundation walls at the seal point between the wall and the concrete slab. I remembered back about 5 years before that when I had been working at a feed store in Poulsbo. There had been a real demand for perforated black corrugated pipe that we stocked. It came in 50 or 100’ rolls and was used as a drain around foundations. A curtain drain is perforated pipe buried around the outside of a home foundation to redirect stormwater saturating the ground around the foundation. The pipe allows the water to enter through the perforations and be directed to point off the property and into a storm system or drainage ditch. These were being installed to keep homes in place and prevent slippage that can happen when the ground becomes saturated, and the water has no place to go. There had been several cases in the area of homes slipping off their foundations. This home had been built with no curtain drain and the ground around it directed all the water towards the foundation. That was worst case I ever saw, however I have come across other instances of this same problem. In these cases, there was degradation of the concrete wall in places. This was where the wall had spots on it where the surface coating of the concrete had crumbled away and the ground water pushed through the porous layer below and was seeping into the house. One case was caused not by pouring rain but a deep snow melting and saturating the ground. The water was again coming up from the foundation connection to the slab in a basement. The other case was recent and happened when a friend of mine called me to his rental house to investigate a water leak. I noted that the water was squishing up from the flooring covering the concrete floor. After locating the water line coming through the concrete wall and verifying that it was dry, I started to remove the sheetrock from the lower wall by the floor. The sheet rock was wet, as were the sill plate 2X4’s on the floor. After removing the sheet rock and the insulation, I found spots on the concrete wall that were” weeping”. The water intrusion was so slow and insidious that it took about 3 years to make itself known by finally getting under the flooring so when it was stepped on the water squished through the spaced in the flooring. When the location of the foundation is not very accessible (think 2’from garden shed to side of house). He had the foundation wall removed and the concrete wall resealed. He then re-did the sheetrock and insulation. When possible, if you are living in an area that gets appreciable levels of rain in a season, it may benefit you to spend a summer digging close to your foundation down to the footing and install perforated pipe along the foundation wall to direct water away from the house and into a French drain or some other drain system, you may save yourself a bit of worry when it rains.