A second layer of shingles over the first is cheaper, faster, and in much of Minnesota not permitted. The reason is hail, and it is written into how the building code classifies this part of the state.
Where the building code identifies a moderate hail area, asphalt shingles may not be applied over an existing roof covering — so a re-roof is a full tear-off down to the deck. If a quote is noticeably cheaper than the others and says “layover,” “overlay,” or “second layer,” that is the difference, and it is not a difference you want to win.
In a moderate hail area, no. The building code classification does not allow asphalt shingles to be applied over any existing roof covering, which means a re-roof is a tear-off to the deck. Dakota County is published as an example by its own cities; the classification covers much of the metro.
This is one of the few questions where the answer genuinely is settled rather than a matter of professional preference. A contractor offering a layover in an area where it is not permitted is offering you something a building inspector can fail.
City of Burnsville: “Dakota County is in an area that is identified as a moderate hail area in the building code. What this means for you is that the building code will not allow asphalt shingles to be applied over any existing roof covering.” Source: City of Burnsville, Re-Roofing With Asphalt Shingles
Two layers of asphalt behave differently under impact from one. The lower layer is no longer bedded flat on a solid deck — it sits on the texture of the roof underneath it, so an impact that would be absorbed by a supported shingle instead flexes it into a void and cracks the mat.
The second problem is that you cannot see the deck. A tear-off is the only point at which anyone looks at the plywood: rot around a chimney, a soft patch under an old leak, delaminated sheathing. Layover roofs its condition into the dark for another twenty years.
The third is weight, and it is the one people underestimate. A full second layer of asphalt is a meaningful dead load on a structure that was sized for one.
It should say so in words. A tear-off quote names the disposal — a dumpster, a haul-away, a per-square tear-off line, or a stated number of layers being removed. If none of that appears anywhere in the scope, ask directly, in writing.
The tell on price is a quote that is meaningfully below the others for the same roof. Tear-off, disposal and deck inspection are a real share of the job, and a number that leaves them out looks like a better deal right up until the inspection.
If your roof already has two layers on it, there is no version of the work that does not involve removing both. That is worth knowing before you compare numbers.
Where the code requires it, a tear-off is the cost of replacing the roof, not an upgrade on top of it. Carriers differ in how they handle code-driven costs and some policies carry specific ordinance-or-law provisions, so the answer is in your policy rather than in a general rule.
What helps is documentation: the estimate naming the code requirement behind the line, rather than a lump sum that invites a line-by-line argument. We write scopes that way as a matter of course, because a scope that cites the rule is harder to shave than one that does not.
This page quotes Minnesota statutes and the adopted Minnesota building code and links to the official text of each so you can read it yourself. It is general information from a licensed contractor, not legal advice, and it is not a substitute for reading your own policy. Statutes and codes are amended; the linked sources are authoritative, this page is not. Last reviewed 2026-10-27.
Straight answers to the questions Minnesota homeowners ask before they call anyone.
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Read the FAQ →We’ll walk it, photograph it, and give you a written scope that says exactly what is required and why. Retail or insurance.
We’ll walk the roof, photograph what we find, and hand you a written scope that names the code requirement behind every line. Yours to keep, whoever does the work.
We measure the work by how it holds up — and by what clients say once we're gone.