If you're a general contractor, property owner, or developer hiring a roofing subcontractor, requiring additional insured status on their GL policy isn't a formality — it's one of the most important risk transfer mechanisms in commercial construction. And if you're a roofing contractor wondering why every GC demands it, understanding additional insured endorsements will help you respond faster, avoid project delays, and demonstrate the kind of insurance sophistication that wins repeat business.
What Additional Insured Actually Means
When a roofing contractor adds a general contractor or property owner as an "additional insured" on their general liability policy, they're extending their policy's coverage to protect that third party against claims arising from the roofer's work. If a lawsuit is filed naming both the roofer and the GC (which is standard practice in construction litigation — plaintiff attorneys name everyone), the roofer's GL policy responds to defend and potentially indemnify the GC.
Without additional insured status, the GC would need to rely solely on their own GL policy to defend against claims arising from the roofer's operations. That costs the GC money, affects their loss history, and potentially exhausts their limits for claims they didn't cause.
Additional insured status is created by an endorsement to the roofer's GL policy — a formal amendment that modifies the policy to include the named party. The certificate of insurance references the endorsement, but the endorsement itself is what creates the coverage.
CG 20 10 vs. CG 20 37: Know the Difference
Not all additional insured endorsements are equal. The two most commonly required forms are ISO standard endorsements:
CG 20 10 — Additional Insured – Owners, Lessees or Contractors – Scheduled Person or Organization (Ongoing Operations):
- Provides additional insured coverage for claims arising from the named insured's (roofer's) ongoing operations
- Covers the additional insured while work is in progress
- Does NOT cover claims that arise after the work is completed
- This is the more basic of the two endorsements
CG 20 37 — Additional Insured – Owners, Lessees or Contractors – Completed Operations:
- Provides additional insured coverage for claims arising from the named insured's completed operations
- Covers the additional insured for claims that arise AFTER the work is finished
- This is critical for roofing work where defects may not manifest for months or years after completion
Why GCs require both: Most sophisticated GCs and their risk managers require CG 20 10 AND CG 20 37 together. CG 20 10 covers them during the project; CG 20 37 covers them after the roofer leaves. A roof leak that causes interior damage two years after installation would trigger the completed operations endorsement. Without CG 20 37, the GC would be on their own for that claim.
Some carriers use proprietary endorsement forms that combine both coverages or use slightly different language. When a GC requires specific ISO form numbers, check with your agent to confirm your carrier's endorsement provides equivalent or broader coverage.
Why GCs Require Additional Insured Status
From the GC's perspective, there are several compelling reasons:
Risk transfer: The GC hired the roofer to do roofing work. If that work causes damage or injury, the claim should be handled by the roofer's insurance, not the GC's. Additional insured status makes this happen without the GC needing to file a cross-claim or third-party action against the roofer.
Defense costs: Even frivolous lawsuits cost money to defend. With additional insured status, the GC gets a defense under the roofer's policy for claims arising from roofing operations. Defense costs can easily reach $50,000-$200,000 even for claims that are ultimately dismissed.
Contract compliance: Most commercial construction contracts (AIA, ConsensusDocs, custom forms) include insurance requirements that mandate additional insured status. If you can't provide it, you can't sign the contract. Review the AIA contract insurance requirements to understand how these provisions work.
Project owner requirements flow down: The project owner requires the GC to be named as additional insured on all subcontractor policies. The GC passes this requirement to every sub, including roofers. It's a chain of risk transfer from the top down.
How to Add Additional Insured Endorsements
The process is straightforward but requires coordination with your agent:
1. Blanket vs. scheduled endorsements: A blanket additional insured endorsement automatically extends AI status to any party required by written contract, without needing to specifically name each entity. A scheduled endorsement names specific parties. Blanket endorsements are more convenient and increasingly common — they eliminate the need to add each GC individually.
2. Request timing: Have your agent add the endorsement before you sign the subcontract. GCs review certificates before allowing you on the jobsite. Last-minute certificate requests cause delays, and delay costs everyone money.
3. Cost: Adding additional insured endorsements typically costs $25-$100 per endorsement if scheduled, or a flat annual charge for blanket endorsements (often included in the policy premium or charged as a small percentage). The cost is negligible compared to losing a contract over it.
4. Certificate documentation: Once the endorsement is added, your agent issues a certificate of insurance referencing the additional insured status. The certificate should note the specific endorsement form (CG 20 10, CG 20 37) and identify the additional insured party by their exact legal name.
Common Mistakes Roofers Make With Additional Insured
Listing them on the certificate but not the policy: A certificate of insurance that says "Additional Insured" in the description but isn't backed by an actual endorsement on the policy is meaningless. If a claim occurs, the supposed additional insured has no coverage. This happens more often than it should, usually due to rushed certificate requests.
Using the wrong endorsement form: Providing CG 20 10 (ongoing only) when the contract requires both CG 20 10 and CG 20 37 (ongoing + completed operations). The GC's risk manager will catch this and send the certificate back — costing you time and credibility.
Not understanding what triggers coverage: Additional insured coverage is limited to claims arising from the named insured's (your) operations. If the GC is sued for something unrelated to your roofing work, your policy doesn't respond just because they're an additional insured. The nexus must be your work.
Forgetting about the umbrella: Many contracts require additional insured status on both the GL and the umbrella policy. If your umbrella doesn't follow form with additional insured endorsements, there's a gap between your GL limits and the umbrella coverage for the additional insured.
Not carrying completed operations coverage: Some roofing GL policies sunset completed operations coverage (it ends when the policy expires and isn't available going forward). If a GC requires CG 20 37, your completed operations coverage must be maintained for the duration specified in the contract — sometimes 3-5 years after project completion.
The Bottom Line for Both Sides
For GCs and property owners: requiring additional insured status is standard risk management. Don't skip it, even for small roofing projects. Verify the endorsement forms, confirm they match your contract requirements, and check that the umbrella follows form.
For roofing contractors: treat additional insured requests as a routine cost of doing business, not an inconvenience. Carry a blanket additional insured endorsement on your GL and umbrella, respond to certificate requests promptly, and work with an agent who understands the endorsement forms that commercial construction demands. The roofers who handle this efficiently are the ones who get called back for the next project.