What a roof replacement costs around Boston
Ask three contractors what a roof costs here and the answers can sit thousands of dollars apart without either extreme being dishonest. In this region the first reason is usually simple: one of them priced a shingle roof, and the house has a flat one.
The question that comes before price
What kind of roof is it? On a pitched roof the answer is shingle and the job is familiar: layers off, deck checked, new covering down. On the flat or shallow main roof of a three-decker or a mill-era two-family, the answer is a membrane, the trade is different, and the lifespan is shorter — fifteen to twenty-five years rather than twenty to thirty. Two bidders who answered that question differently are not competing on the same job.
A great many houses in this crown have both: a pitched front section and a flat rear one, or a main roof and a low-slope porch stack behind it. Those need to be priced as two roofs, in two materials, and a single number covering « the roof » is worth a follow-up question.
The lines that move the number
Layers first: code allows two, and on housing built between 1890 and 1930 a third turns up regularly, which turns a recover into a full strip and doubles the disposal weight. Decking second, priced per sheet — and here comes the local wildcard, because anything roofed a century ago sits on spaced boards that modern shingle cannot be nailed to. Sheeting over them is real material and labour, and a quote that never mentions it either has not looked or is planning to raise the price mid-job.
Then the details this housing makes likely. Ventilation, which on a pre-1940 house usually has to be created rather than corrected, and which is the single largest lever on how long the new covering lasts. Drainage, on anything flat: scuppers, internal drains, the parapet. The rear porch roof. And within a mile of the water, corrosion-resistant metal replaced rather than reused, because salt finishes the junctions years before the field.
Why timing changes the quote
The working season here runs roughly April into November, and it is narrower for membrane work than for shingle because flat-roof materials have a minimum application temperature. That is seven usable months in a region with a lot of century-old housing, so the good crews commit early. Quotes gathered in January and February get attention and a choice of dates; a call in September gets whoever has a gap before the cold closes the season.
Before you sign, make every bidder answer
- Is this a shingle roof or a membrane roof — and did you price the right one?
- On this housing the two are different trades with different lifespans, and a bidder who assumed shingle on a flat roof has quoted a job that cannot be done. Where a house has both a pitched and a flat section, ask for two numbers rather than one.
- How many layers come off, and is disposal in the price?
- Two is the code maximum and a third is a regular find on housing from the mill years, which turns a recover into a full strip. Get the count the estimator actually observed, and get the dumpster stated inside the number rather than beside it.
- What is the per-sheet decking rate, and what if the sheathing is spaced?
- Two separate answers. The rate covers soft boards; the second covers the local wildcard, because a house roofed a century ago sits on gapped planks that have to be sheeted over before modern shingle can be nailed down.
- Is the rear porch roof included, and in what material?
- On a three-decker it is a separate roof — smaller, usually older, and out of sight from the street. It is the most commonly omitted line in a local quote, and paying for it afterwards means paying a price nobody competed for.
- Is the attic getting intake and exhaust, or only what it already has?
- Both, balanced to each other, and on a pre-1940 house the honest answer is usually that they have to be created. Ice at the eave is a heat problem before it is a water problem, and replacement day is the only time the correction is inexpensive.
- Near the water: is the metal corrosion-resistant, and replaced or reused?
- Within a mile of the shore, flashings, collars, fasteners and drip edge fail years before the covering they serve. Sealing over the old metal is where a coastal quote gets cheap, and it is why the roof leaks at its joints while the field still looks sound.
Next step: Three-decker roofs: the different job