Are foundation drains present in every older Ottawa house?

No, foundation drains are not present in every older Ottawa house. The City of Ottawa says that in some older homes they may not be present at all, and in others they may exist but be connected to the sanitary or combined sewer rather than the storm sewer.

Ontario's Building Code (clause 9.14.2.1) requires drainage at the bottom of every foundation wall that encloses the building interior, unless it can be shown to be unnecessary. Where drain tile is used, it is at least 100 mm in diameter, laid with its top below the bottom of the floor slab and covered on the top and sides with at least 150 mm of crushed stone or other clean coarse granular material (9.14.3.2, 9.14.3.3). It drains to a sewer, a drainage ditch or a dry well, or to a sump with a pump where gravity drainage is not practical (9.14.5).

The City notes that foundation drains collect groundwater from around the foundation and carry it to the storm sewer by a storm lateral. Where a drain exists but runs to the sanitary sewer, the City says that connection should not be there. The City lists failed foundation drains as one of the things a backwater valve or sump pump will not fix on its own.

Ask any contractor quoting interior or exterior drainage work how they will find out what drains your house has and where they go, and have that written into the quote.

If you want to hear from local contractors who work on foundation drainage in Ottawa, the request form on this site sends your details to contractors listed in the Ottawa Construction Network directory.