Sooner or later a general contractor hands a roofing sub a contract with a line in it that says the GC must be named as an additional insured on your general liability, paired with a demand for a certificate of insurance proving it. It is one of the most common requirements in commercial roofing — and for a roofing contractor it usually takes two endorsements, not one. This post explains what the demand is really asking for, which real endorsements do the work, and why one of them matters far more to a roofing business than the other.
The short version: additional-insured status is added by a real endorsement to your general liability, not by the certificate that proves it exists. In ISO’s system the two that matter are CG 20 10 for your ongoing operations while your crew is on the roof and CG 20 37 for your completed operations after the roof is done — and for a trade with roofing’s long tail on the work it leaves behind, the completed-operations one is the piece that gets missed. The general liability page owns the coverage architecture; this post is about the contract document that demands it and how the two endorsements answer it.
Certificate-of-insurance season: what the contract is actually demanding
The requirement is almost never a handshake. It is a clause in a subcontract, a master services agreement, or a purchase order, and it comes paired with a demand for a certificate of insurance evidencing it. What a roofing contractor has to understand is that the clause is asking for two related but different things: a real endorsement on the policy that grants additional-insured status, and a certificate that proves the endorsement exists.
The endorsement is the coverage. The certificate is only the evidence. A general contractor who collects a certificate and files it has proof that coverage was represented on a given day — not the coverage itself. The status that actually lets your policy respond on the GC’s behalf lives on the endorsement attached to your policy, which is why the honest first move is always to read what is on your declarations page rather than trust that a certificate settles the question.
CG 20 10 versus CG 20 37: the ongoing / completed-operations split
When a contract asks you to add a general contractor as an additional insured, the coverage is granted by a specific endorsement attached over the standard commercial general liability form — typically the occurrence version known as CG 00 01. In ISO’s system the two endorsements that matter for a roofing sub are:
- CG 20 10 — ongoing operations. Adds the general contractor as an additional insured for your ongoing operations, the protection it wants while your crew is on the roof and the work is in progress.
- CG 20 37 — completed operations. Extends that additional-insured status to your completed operations, the protection the GC wants after the roof is finished and your crew has left.
They are not interchangeable, and they are not a matched set you automatically get together. Older additional-insured forms once folded both windows into a single endorsement; ISO’s modern forms split them apart, so completed-operations status now comes from its own endorsement rather than riding along with the ongoing-operations one. A policy can carry one without the other, which means a general contractor can hold an endorsement that covers it for the wrong window entirely. Editions and exact form language vary by carrier, so the form number written into a contract is a starting point to confirm against your policy, not proof of what is actually attached.
Why the completed-operations endorsement is the one roofing subs miss
The reason the pair matters comes straight from the nature of roofing. Ongoing-operations status protects the general contractor while your crew is on the roof, but it can leave the GC without additional-insured status once you have wrapped up and gone — and the completed-operations tail is precisely when a roofing claim tends to surface. A roof you installed or repaired keeps existing after final payment: shedding water, taking wind uplift, freezing and thawing, aging in the sun. A leak that opens two winters later, a membrane seam that lets water into the building, or a roof that fails and damages the structure and its contents below is the classic completed-operations claim, and it usually shows up long after the crew has left the site.
That is the gap the completed-operations endorsement closes. It extends additional-insured status to your completed operations, so the general contractor is still protected for liability connected to your finished roof after your crew is gone. Requiring only the ongoing-operations endorsement protects the GC during the weeks you are on the roof and leaves it exposed during the years afterward — which is backwards for a trade whose signature exposure is the work it leaves behind. This is the same completed-operations exposure the general liability policy is built around; the additional-insured endorsement simply extends that one piece to the GC, and only if the completed-operations endorsement is actually on the policy.
Real-World Scenario: A roofing sub re-roofs a commercial building under a general contractor, passes final inspection, and demobilizes. More than a year later a section of the roof fails and water ruins the finishes and stock below; the property-damage claim names both the roofer and the general contractor. Because the roofer’s policy carried the completed-operations additional-insured endorsement the contract required, the general contractor had the status it bargained for on the finished roof — not just for the weeks the crew was on site. Had the roofer added only the ongoing-operations endorsement, the GC’s additional-insured status would have run out the day the crew drove away, right before the exposure it cared about actually surfaced.
Blanket versus scheduled additional insured
There are two ways a policy grants additional-insured status, and the difference is practical. Scheduled coverage lists each party by name on the endorsement — every general contractor added one at a time. Blanket coverage grants the status automatically to any party you have agreed in a written contract to add, without naming each one.
For a roofing contractor bidding job after job, blanket wording is usually far more workable than scheduling every general contractor separately, because certificate requests arrive constantly and scheduling each one by hand is slow and easy to miss. But whether your policy actually carries blanket wording — and whether that blanket wording reaches completed operations, not just ongoing operations — depends on the endorsements attached to your specific policy. Terms and forms vary by carrier, so this is another place to read rather than assume the coverage is broad. The commercial and industrial roofing work where general contractors, additional-insured demands, and higher limits concentrate is exactly where this wording earns its keep.
Wrap-ups: when the additional-insured question changes
On some larger commercial and public projects the owner or general contractor provides the liability coverage for everyone on the job through a wrap-up — an owner-controlled or contractor-controlled insurance program that enrolls the subs under one policy. On a wrap-up job the additional-insured conversation shifts, because the GC’s own program is meant to respond, and your own general liability may be carved back for the enrolled work. It does not make your coverage irrelevant: wrap-ups have eligibility rules, exclusions, and off-site or non-enrolled work that still runs on your own policy, and you still carry your completed-operations exposure on everything the wrap-up does not cover. The honest instruction is the same — read what the specific project documents require against what your own policy actually carries, rather than assume the wrap-up handles all of it.
What additional-insured status does not do
Additional-insured status is about who else your general liability protects — not about widening what general liability covers for you, and not about handing anyone a separate bucket of coverage. The claims an additional insured brings share your limits, which is one reason a roofing contractor watches how many additional-insured requirements are stacking against a single set of limits, and why contracts that demand both higher limits and additional-insured status often push a sub toward an umbrella over the primary policy.
It also does not reach your own people or property. Injuries to your own crew — including a fall from the roof, the signature roofing injury — run through workers compensation, a separate line. Your vehicles run through commercial auto, and your tools, harnesses, and staged materials through contractors equipment. Additional-insured endorsements add a general contractor to your general liability for liability connected to your work; they do not turn general liability into a policy that also answers your crew or your trucks.
Read the contract against your endorsements before the certificate request
The takeaway is straightforward: for a roofing contractor working under general contractors, additional-insured status usually takes two endorsements — one for ongoing operations while you build the roof, one for completed operations after you leave — and the completed-operations piece is the one that gets missed on a policy bought on price. Confirm both are attached, check whether your status is blanket or scheduled, and read a general contractor’s insurance requirements against your own endorsements before you sign, not when a certificate request lands mid-job. Coverage depends on the specific policy and the endorsements actually attached, so it is worth reading rather than assuming. When you are ready, start a quote and send us the contracts you are bidding, read the full general liability page to see how the completed-operations coverage the endorsement extends actually works, or browse the coverage overview to see where each line sits.