Thanks to CuriousCat for this guest post :
“If I were to buy a home today, I would walk around the home to see if there are visible plastic drain clean outs that can be accessed and have the drains checked before buying. If they are not present then I would think that eventually new drainage will have to be installed. The cost of excavating, removing concrete walks around the home’s perimeter and installing new drainage is enormous and I think a rip-off of consumers.” – John Dollar
When we bought our 1940 house, there were white PVC clean-outs around the perimeter of the home and the inspector told us that the drainage system was updated within the last 5 years. The owners stated that they had never had any moisture in the home during the 3 years they’d owned it. The house is on a slope atop of clay. They indicated on the disclosure statement that there were no moisture issues.
Two years later during a major rainfall in December it was as if someone turned on a tap behind the foundation wall. The basement was unfinished but we still had carpets, furniture, TV, and computers in the southern half, and the water was coming in through the northern wall so there was a bit of a buffer and a chance to “save” our possessions. A lot of water was running along these channels on the perimeter of the foundation (like a concrete moat) but it was overflowing. It was about 10pm when we saw the water and using a shopvac we battled the deluge all night, getting up every 20 mins to empty the vacuum. The water didn’t stop coming until it stopped raining, at about 8am the next morning. That same night a neighbour had her entire basement flooded and had to go through insurance to have her furnace replaced. We hoped it was a one-time thing, but then it happened again two years later.
Things that should have tipped us off:
- The concrete foundation walls and floor were painted, likely in an effort to hide water damage.
- The rubber interlocking tiles that the previous homeowner had left behind and we had just put our stuff over top, had this white chalky mineral under them, covering signs of efflorescence.
- The old carpet that had been put over a carpet pad, directly over the concrete, was moldy. We hadn’t checked under these when we had moved in.
When we had Drainscope scope our drains, they informed us that the system had all the right size pipes and that they were clear, but were in fact 6 feet away from the foundation of the house! He told us this was likely due to the homeowner not wanting to rip up the concrete sidewalk that wrapped around the house. He said, “Yeah nice system you got there, but it’s not going to stop the water coming into your house. It’s acting like a curtain drain, so it’s probably helping somewhat?”
I spent a lot of time researching all the options from curtain drains to perimeter drains to sump pumps and got multiple quotes with everyone telling me something different and providing me a different “solution”. Finally, after all this research, I settled on an interior French drain with a sump pump. It was not the cheapest option, but it wasn’t the most expensive either. At this point, we didn’t want to have to pay to break up the brand new concrete patio, the concrete sidewalk, or move the oil tank and heat pump from the side of the house. I decided I would try the cheaper/easier option first and that the external option would still be available if that failed.
Island Basement Systems came and dug a trench in the basement along the north wall. It took two people one day to break up 35 feet of concrete, dig a deep sump pit, and haul away the rubble. The next day they installed a vapor barrier over the foundation wall that directs water into the drain towards the sump pump. The water is allowed to come through the walls, flows down into the drains and into the pit. The sump then pumps the water up through a pipe, through the wall, and ties into my drainage system. The only outside work required was to cut a small section out of the sidewalk and dig a bit of dirt for them to run the PVC pipe from the basement to the clean-out. Two days and $3800 later I was left wondering why I hadn’t done it years earlier! (Honestly, I thought it would be a much more expensive fix!)
The benefit of this solution is that I have physical evidence that it is working. I can hear the pump when it kicks in, which is just 5-10 seconds of whooshing. It goes off so rarely, sometimes I pour water in the pit just to reassure myself it’s still operational! It is covered by a 25 year warranty with the company that installed it. And finally, because it is mechanical, if it fails, my home insurance will cover the damage, much like it would if your indoor plumbing burst. I did not get a battery backup because there usually isn’t a worry of power outages during heavy rains, so I didn’t think it was worth the extra cost. Even if the pump was not working, the system works by gravity, so the water would fill up the sump pit, which is quite deep and large, before harmlessly overflowing into the garage where it’s already sloped to flow out the garage door and down the driveway.
Just for our own peace of mind, we waited two more years before finishing the basement so we could monitor that the system worked. We removed all the rubber mats, allowed the concrete floor to dry out and laid recycled PVC garage floor tiles as a subfloor. This allows the concrete floor to breathe and has no wood to rot. We then laid a water-resistant vinyl floor tile on top. All the walls we built we used gaskets between the pressure-treated lumber and the concrete. In some sections, we even used plywood instead of drywall, because plywood will dry out as long as it has access to air around it.
In the end, this was another challenge of buying an old house in Victoria that I hope we met successfully, but only time will tell. As long as I own this house, the memories of those two long nights vacuuming water will make me forever vigilant. Though 3 years later, a heavy rainfall warning no longer gives me anxiety, so looks like I did buy myself some peace of mind after all.