How is a roof replacement priced?
By the square, which is one hundred square feet of roof surface rather than of floor area. From there the number moves on five things: the pitch, how many existing layers come off, the condition of the decking underneath, the amount of flashing and detail work, and the material you choose. Two honest quotes on the same house can differ because they scope those differently.
A square is not a square foot
The trade prices in squares, and one square is one hundred square feet of roof surface. A house with two thousand square feet of floor area does not have twenty squares of roof, because the roof is pitched and its surface is larger than the footprint, and because of overhangs, dormers and garage roofs.
This is the first reason online estimates are so unreliable. Anything working from floor area or from a satellite outline is approximating the number that matters.
The five variables
Pitch. A roof a crew can walk on is faster and safer than one that needs staging and harnesses, and steep roofs carry a real labor premium.
Layers. Tearing off one layer and tearing off three are different jobs with different disposal costs. The code limits how many layers are permitted in the first place.
Decking. Nobody can price this from the ground, because the deck is under the roof. Soft, rotted or delaminated sheets have to be replaced, and a quote that pretends this will never happen is either optimistic or planning to raise the price later. A good quote states the per-sheet rate up front.
Detail. Valleys, chimneys, dormers, skylights, wall terminations and pipe penetrations are where the labor is and where the leaks come from. A simple gable roof and a complicated roof of the same area are not the same job.
Material. Three-tab, architectural, impact-resistant and designer shingles cover a wide range, and impact-resistant products can attract an insurance discount in a hail region, which is worth asking your carrier about.
What to compare between two quotes
Not the totals. Compare the scope line by line: how much underlayment and what type, whether ice and water shield goes in the valleys, whether the flashing is new or reused, how many nails per shingle, what ventilation is being installed, what the decking replacement rate is, and what warranty is attached.
Reused flashing is the most common invisible saving. It looks identical from the curb on the day the job finishes and it is the part most likely to be leaking in four years.
Where insurance changes the arithmetic
On a claim the number is usually set by the carrier’s scope rather than by a contractor’s quote, and the conversation shifts from price to whether the scope covers what the roof actually needs. Missing line items are common, and getting them added is a documentation exercise.
Your deductible is yours. Any contractor offering to absorb it is proposing insurance fraud, which is a criminal matter in Texas.
Related questions
Can I get a price over the phone?
You can get a range. You cannot get a price, because nobody has seen the pitch, the layers, the detail or the decking. Anyone quoting a firm number without looking is guessing or planning to revise it.
Are impact-resistant shingles worth it?
In a hail region they resist bruising better and many carriers offer a premium discount for a Class 4 product. Ask your insurer what the discount would be and weigh it against the extra cost over the life of the roof.
What happens if you find bad decking?
It gets replaced, because a new roof over a soft deck is a waste of both. The rate should be in the estimate before the job starts so it is a known number rather than a surprise.
