Should I hire a commercial roofer for a flat roof on my house?

Often, yes. Low-slope membranes such as EPDM, TPO, PVC, modified bitumen and built-up roofing are the bread and butter of commercial roofers, while many residential roofers spend most of their time on shingles. A company that installs your type of membrane every week can be the better choice for a porch, addition or low-slope house. The catch in Virginia is the licence: "commercial" on the truck tells you nothing, and one kind of commercial licence does not allow work on houses at all.

The licence decides whether they can do it

Virginia's Board for Contractors licenses roofing as its own specialty. The roofing contractor (ROC) specialty covers installing, repairing, removing or improving the materials that form a watertight, weather-resistant surface for roofs and decks, including roof insulation above the deck.^[1] It is not limited to one type of building. The commercial building (CBC) and residential building (RBC) classifications and the home improvement (HIC) and commercial improvement (CIC) specialties also provide for this function,^[1] but each of those has its own limits.

The one to watch is the commercial building classification. Its definition says that it "does not allow construction, repair, or improvement of dwellings and townhouses."^[2] The commercial improvement (CIC) specialty is likewise limited to structures that are not dwellings or townhouses.^[1] The home improvement (HIC) specialty and the residential building (RBC) class are the ones written for houses.^[1][2]

So a "commercial roofer" with the ROC specialty can work on your house. A company whose only licence is CBC or CIC cannot, however good its commercial work is. DPOR's lookup shows each licence's class and specialties; check it using DPOR's License Lookup or by calling (804) 367-8511.^[6] Make sure the licence class fits the size of the quote. How to check a contractor's licence walks through the lookup.

The Recovery Fund has limits

Virginia's Contractor Transaction Recovery Fund is a backstop when a licensed contractor's improper or dishonest conduct leaves you with a court judgment you cannot collect. The Contractor Transaction Recovery Fund may pay claims up to $20,000^[4] to qualifying consumers, and it pays only to someone with an unsatisfied judgment involving residential construction.^[3] The statute also leaves out one group by name: its definition of a covered contractor "shall not include contractors holding only the commercial building contractor classification."^[3] Hiring a company licensed for residential work keeps that protection.

Residential contract rules still apply

Virginia's rules for residential contracting require a legible written contract signed by both sides before work starts or any payment is accepted.^[5] The minimum terms include start and estimated completion dates, the total cost, the payment schedule and down payment, the materials and work, a promise to comply with local permit, inspection and zoning requirements, the contractor's licence number, class and specialty, and a notice about the Recovery Fund.^[5] A commercial firm used to bid documents and purchase orders may not have a residential contract ready. Ask to see it before you sign anything.

What to ask any roofer, commercial or residential

Experience with your membrane. DPOR's own advice is that for roofing-only work you may want to hire a contractor licensed in that particular specialty.^[4] Beyond the licence, ask how many roofs of your type they installed in the last year and for addresses you can look at. Workmanship decides how flat roofs perform: federal roofing guidance stresses that the success of a built-up roof depends on sound installation technique and quality control.^[7] The same is true of seams and flashings on every membrane.

How they will apply it. Some modified bitumen sheets are torched on. On a wood-framed house that deserves a direct question. The Defense Department's roofing criteria put it plainly: If materials or structures are combustible, torch application is prohibited and another method must be used,^[7] and where torching is used, the contractor must keep a two-hour fire watch after the last torch is out.^[7] Self-adhered and cold-applied systems avoid open flame.

The warranty. Ask which manufacturer's warranty is included, by name, whether that warranty requires an approved installer, and whether this roofer is approved to register it. Ask, too, who will come back for inspections; one membrane maker's maintenance guide recommends at least one inspection per year be done by the contractor that installed the roof.^[8]

Living in the house during the job. A commercial crew may be used to empty buildings. Ask how they protect the interior, gutters, siding and landscaping, how they keep the roof watertight overnight, and how loud and long the job will be.

Whether the job fits them. Some commercial firms do not take small residential jobs, or price them high to cover crew and equipment moves. That is not a reason to hire someone less qualified, but it is a reason to get more than one quote. Get at least three estimates whenever possible.^[6]

When to call a licensed pro

Any work on a flat roof is a job for a licensed roofer, not a homeowner on a ladder. Once you have a shortlist, compare itemized quotes on the same specification, and keep the deposit small: DPOR's advice is "Pay 10 percent down or $1,000, whichever amount is less."^[6] Read what drives the cost of a flat roof replacement and the main kinds of flat roof systems before you meet roofers, so you can ask the right questions.

More exterior answers cover steep roofs and gutters. To compare licensed roofers near you, browse flat roofing on Loclis or exterior contractors in Blacksburg. Loclis lists businesses from Virginia's DPOR register with each one's licence number and class.

Describe your flat roof once and licensed local roofers send a price or offer an estimate visit; any paid visit fee comes off the final price.