A house starts falling apart as soon as it's put together... and it keeps falling it apart, and you have to keep putting it back together. The distribution of expenses is lumpier with a house than with a condo, but it's certanly an ongoing cash outflow.
My last house I did, essentially, zero maintenance over a 10-year span except for a drain replacement ($2K). Every other expense was month to month expenses like heating and electrical.
When I finally decided to sell, I replaced the crappy carpet, painted the walls beige and made a 5x profit.
That's true for inner Toronto but not for the suburbs as manishsharan suggested. Newer developer-built-subdivision wood-frame rules out there.