Buying The House
A roof is one of the largest single items on a house and one of the least examined during a purchase, because the general inspection rarely goes that far.
Short answer
A general home inspection typically looks at the roof from the ground or from a ladder at the eave, and rarely assesses the attic in detail. In Toronto the attic is where the answer is. A separate roof inspection, with the attic included, tells you the remaining life and the ventilation position — which is the number that matters.
What the general inspection misses
A walked roof, which many inspectors will not do for liability and insurance reasons.
A detailed attic assessment, which is where previous leaks, frost history and blocked venting show.
Flashing condition at the chimney and the sidewalls, which is the most common leak source and needs looking at closely.
Valleys, which need to be seen rather than inferred.
The difference in age between slopes, which affects how long you have.
And whether a previous repair was done properly or cemented over, which a close look reveals immediately.
What you are buying with it
A remaining-life range with reasoning, a defect list with locations and photographs, and an explicit ventilation assessment. On a Toronto house that last one predicts both the ice dam trouble and how long the next roof will last, and it is the thing nobody else will tell you.
The specific Toronto things to establish
Ice dam history, which shows in the attic as staining and frost evidence at the eave even if the vendor says nothing.
Whether there is ice and water shield, which on an older roof there may not be, and which cannot be added without opening the roof.
How many layers are on the roof, because two means a tear-off and a higher future cost.
Whether the bath fans vent outside or into the attic, which is extremely common and is both a moisture and a code issue.
Insulation depth and whether it is blocking the soffits.
And the chimney, including the flashing and the masonry, because on an older Toronto house that is frequently a bigger item than the roof.
Using the result
A roof at the end of its life is a price negotiation with a real number behind it, which is far stronger than a general comment in an inspection report.
A ventilation defect is a cheap fix you can plan for, and knowing about it is worth more than the fee.
An active leak is a different conversation and may be a condition of closing.
Attic mould is a disclosure and remediation question, and it is worth knowing before rather than after.
Keep the report, because it is also the pre-storm documentation if you ever make a wind claim.
And budget from it, because a roof you know is five years from replacement is a plan rather than a surprise.
Common questions
Is a home inspection enough for the roof?
Rarely. Most do not walk the roof or assess the attic in detail.
What should I establish in Toronto specifically?
Ice dam history, whether there is ice and water shield, layer count, and the bath fan terminations.
Is it worth the fee?
On the largest single item on the house, generally yes — and the report is useful later for a wind claim.