Roof replacement
Replacing a roof on housing this old is mostly a question of what is underneath, and on a building with more than one household it is also a question of where the heat comes from. Neither of those is the covering, and both of them are where two honest quotes separate by thousands.
What the tear-off is going to find
Boards laid with gaps are normal on anything built before the war here, sized for a material that was hung rather than nailed flat. A modern covering needs a continuous surface, so putting a new deck down is frequently part of the job rather than an exception. It belongs in the price before the roof is opened.
Layers are the second unknown. Re-covering was normal for decades, and these houses can be carrying two or three generations of material. A tape measure at the rake edge settles it in a minute, and any bidder can do that before quoting.
The eave, and who is heating the top floor
On a building with a heated top flat, the eave is the part that decides how the roof ages. Warm air under the deck melts snow mid-slope; the water reaches an overhang that sits over outside air and refreezes there.
That means the useful lines in the quote are the membrane at the eave — how far past the wall line does it run — and what happens to the intake and exhaust. On a building like this the code minimum was written for a different house.
A quote that prices only the covering is quoting a symptom. It is not dishonest; it is simply answering a smaller question than the one you have.
Access, on lots that have none
Across much of this market the houses touch or nearly touch. Where the container goes, how material gets up, how debris comes down and how the neighbours on both sides are protected are real hours, and they belong in the number rather than in the surprise.
Ask about it plainly. A contractor who prices access openly is one who has planned to do the awkward parts properly.
Reading two quotes on the same house
The spread is rarely the shingle brand. It is whether a new deck is priced, whether the membrane at the eave is specified by distance rather than by name, whether intake and exhaust are corrected or reinstalled as found, whether flashings are rebuilt or re-used, and whether access has been accounted for.
The comparison tool on this site walks those points one at a time.
What to ask every bidder
- What happens if the boards are spaced rather than solid?
- On pre-war housing here that is likely rather than possible. Ask for the price per sheet of new decking, with an assumed count, before the roof is opened.
- How far past the wall line does the eave membrane run?
- Not whether it is there — how far. On a building with a heated top floor, the heated space reaches further up the slope than the code minimum assumes.
- Is the intake at the soffit being corrected, or left as found?
- A ridge vent with no intake pulls heated air out of the house and into the roof, which is exactly what causes the ice. Half a system is worse than none.
- Is the flashing at the chimney let into the brick, or fastened to the face?
- Two different prices and roughly a decade apart in service. On a disused chimney it is worth asking whether it needs to stay at all.
- Where does the container go, and who protects the neighbours?
- On a lot with no side yard this is real labour and real risk. A bidder who has an answer has walked the property.
- 1 The ridge. One ridge over two households, and one of them pays to replace it.
- 2 The field. The part everyone looks at, and rarely the part that actually failed.
- 3 Valleys. Most of them were cut in later, when the house was divided into flats.
- 4 The chimney. Often two of them, and often neither one carries anything any more.
- 5 Penetrations. Two kitchens and two bathrooms mean twice the holes on the same roof.
- 6 The overhang. Where heat from a flat you do not control comes back down as ice.