Case Study: A RAIN Home Visit
Main water related concerns:
• Multiple downspouts connected directly to aging storm sewer laterals
• Back and side yard area graded towards the house
• Moisture and effervescence in basement
• Downspouts emptying too close to the house
• Rain barrels often overflowing
• Worn asphalt driveway is graded towards the house
This house was chosen as a case study because it shows many of the issues that are address through the RAIN Home Visit program. I enjoyed my visit at this house, mostly because the homeowner was very friendly and welcomed my suggestions with an open mind. But on top of that – this home was a classic example of how mismanaging water outside can and will lead to issues inside.
This home is built in a neighbourhood where downspouts connect directly into the municipal sewer system. Connected downspouts are concerning from an environmental as well as a safety perspective. The bottom line is that I do not trust what I cannot see and there is no guarantee that those 80 year old sewer laterals are working properly. Over time they get clogged and cracked by things like leaves, soil, animal burrows, and tree roots. Most homeowner assume these underground pipes are doing their job, but moist basements tell a different story.
This homeowner recently had the eaves and downspouts replaced. However, the grading of the eaves and position of the downspouts was not changed and they were connected right back into the municipal system. When replacing eaves and downspouts, take a look at the roof area and consider an ideal drainage method. Downspouts should be positioned 8-10 feet and downhill from the foundation onto a permeable area. Where possible, avoid placing downspouts on driveways and patios. During the tour of the basement I saw exactly what I was expecting to see – moisture. The area where the walls met the floor was damp, and the walls were covered in a white mineral deposit known as efflorescence.
If you have efflorescence in your basement don’t worry, it is not toxic, but, it is a definite sign that there is moisture in the soil surrounding your foundation. Excess moisture in the soil applies pressure against your foundation, which is one of the causes of pressure cracks. Water is always looking to flow where there is less pressure – and over time can force itself through your foundation. Efflorescence is not a toxic concern, but it is a sign that action is needed to keep your foundation safe and dry.
The ground surface in the back and side yard being graded towards the foundation was another concern. The lowest point in the backyard was where the lawn met the foundation – an immediate sign that the area needs regarding. I noticed that about 6 inches away from the house the vegetation had changed sharply from lawn to a low growing yellow flowered ground cover. Sharp changes in vegetation means that the moisture pattern in this area is not what it should be (in this case the area next to the foundation was too wet for lawn to grow).
Main lessons learnt:
• Disconnect downspouts from sewer laterals and direct them onto a permeable surface 8-10 feet and downhill from the foundation.
• Make sure the land surface is always graded away from the house to ensure water is flowing away from the foundation.
• Where possible, try to maintain an 8-10 foot ‘dry perimeter’ around your house where no water is soaking into the ground. Water can be safely absorbed into the ground beyond this 8-10 foot perimeter.
• Fully empty all rain barrels after each rain so the barrel has full capacity for the next rain event.