When you think of a sub-contractor, you envision a General Contractor calling "Bob's Roofing" or "Tito's Electric" to come out and do the work under his supervision. This decision is often motivated by bottom-line dollars and cents. No one wants to take that gamble with their roof. After all, you're researching and vetting the roofer, not some guy he's hiring because they gave him a dirt-cheap bid.
Our crews only work for us and do nothing else; everyone is a specialist. We do pay them per job and based on the square and pitch of your roof so their compensation can vary weekly. For this reason, we pay them as 1099 contractors, but that's only for tax purposes. They all carry their own Worker's Compensation / Liability insurance and we have an additional umbrella policy on every job site.