in my 20+ years of living in the boston area, the only times the landlord was ever responsible for property maintenance was when it was a large (4+ unit) building. these smaller 2- and 3-family houses in somerville, it's mostly up to the tenants by default, since the landlords are out in the 'burbs, or in another state.

in all cases, check the rental agreement, then double-check with your landlord if you're not sure.