Summary

Hiring the wrong flat roof subcontractor can cost Indiana general contractors thousands of dollars in delays, callbacks, warranty disputes, and lost client trust. This guide outlines the major red flags that reveal when a roofer is inexperienced, unqualified, or incapable of handling commercial flat roof systems. By spotting these warning signs early, contractors can protect job timelines, ensure code compliance, and safeguard their reputation.

Introduction: Why GC’s Must Spot Roofing Red Flags Early

Commercial flat roofing is one of the most failure-prone trades in construction. Bad installation, sloppy flashing, poor drainage design, and weak insulation planning cause the majority of leaks—not defective materials. In Indiana’s climate, where winters, snow loads, and freeze–thaw cycles expose poor workmanship quickly, an inexperienced roofer becomes a liability to your entire project.

The problem isn’t just fixing leaks later. It’s the callbacks, warranty headaches, schedule delays, and damage to the general contractor’s reputation. The good news? Most inexperienced roofers show clear red flags long before they touch your job site.

This guide helps you identify those warning signs immediately—before they cost you time, money, and credibility.

Red Flag #1: Vague or Missing Documentation

Professional commercial roofers have complete documentation ready from day one. Inexperienced subs tend to be disorganized, evasive, or completely unprepared.

Major documentation red flags

• No written scope of work
  
  
  

• Missing insurance certificates
  
  
  

• Cannot provide workers’ compensation proof
  
  
  

• No manufacturer certifications
  
  
  

• Refuses to name brands or membrane thickness
  
  
  

• Cannot show references or completed large commercial projects
  
  
  

Why this matters for contractors

Documentation is the foundation of:

• Warranty compliance
  
  
  

• Liability protection
  
  
  

• Schedule accuracy
  
  
  

• Budget control
  
  
  

If they can’t get paperwork right, they won’t get the roof right.

Red Flag #2: Unrealistically Low Pricing

If a roofer is 20–40% below market rate, they are likely cutting corners in places you cannot afford.

Common cost-cutting tactics of inexperienced roofers

• Using off-brand membranes
  
  
  

• Installing thinner materials (45 mil instead of 60–80 mil)
  
  
  

• Avoiding tapered insulation
  
  
  

• Skipping flashing reinforcements
  
  
  

• Hiring untrained day labor
  
  
  

• Ignoring moisture or deck issues
  
  
  

• Rushing welds or adhesive cures
  
  
  

Why contractors should avoid bargain bids

Cheap roofing always becomes expensive roofing—after leaks, change orders, and rework.

A low bid is a warning, not a bargain.

Red Flag #3: Poor Understanding of Flat Roof Systems

Flat roofing isn’t like shingle roofing. It requires precision, system knowledge, and manufacturer training.

Red flags showing lack of system expertise

• Doesn’t know differences between TPO, EPDM, and PVC
  
  
  

• Claims “all flat roofs install the same”
  
  
  

• Avoids discussing welding parameters
  
  
  

• Doesn’t know adhesive cure times
  
  
  

• Cannot explain fastener patterns
  
  
  

• Avoids questions about flashing or term bars
  
  
  

Why this matters

Commercial roofing has zero margin for error.
If they don’t understand the system, they will not install it correctly.

Red Flag #4: Avoiding Drainage and Tapered Insulation Discussions

Drainage is the #1 reason flat roofs fail—and inexperienced roofers avoid the topic because they lack the skill to design proper slope.

Drainage-related red flags

• Says “drainage won’t be a problem” without measuring slope
  
  
  

• Doesn’t include tapered insulation in the proposal
  
  
  

• No plan for crickets behind HVAC units
  
  
  

• Claims dead-level roofs are acceptable
  
  
  

• Doesn’t know code-required slope (¼ inch per foot)
  
  
  

Why this matters

Bad drainage = ponding
Ponding = membrane breakdown
Membrane breakdown = guaranteed leaks

Any roofer who avoids drainage planning is dangerous.

Red Flag #5: Weak Flashing and Penetration Standards

Flashing is the most technical part of flat roofing—and the most common failure point.

Flashing red flags

• Low flashing height
  
  
  

• No reinforced inside/outside corners
  
  
  

• Sloppy curb flashing
  
  
  

• No termination bars
  
  
  

• No metal edge detail
  
  
  

• Over-reliance on caulking instead of membrane work
  
  
  

Why this matters for GCs

Leaks don’t happen in the middle of the roof.
They happen at:

• Walls
  
  
  

• HVAC units
  
  
  

• Pipes
  
  
  

• Curbs
  
  
  

• Edges
  
  
  

Bad flashing = nonstop callbacks.

Red Flag #6: Lack of Crew Structure or Training

Even a knowledgeable foreman can’t compensate for a weak crew.

Crew-related red flags

• Entire crew is day labor / 1099
  
  
  

• High turnover
  
  
  

• No system-specific training
  
  
  

• Crew size too small for job deadlines
  
  
  

• No clear foreman
  
  
  

• No safety plan
  
  
  

Why this matters

Untrained crews:

• Make mistakes
  
  
  

• Cause OSHA issues
  
  
  

• Miss deadlines
  
  
  

• Install systems incorrectly
  
  
  

Your timelines will suffer.

Red Flag #7: No Moisture Scanning or Deck Inspection Process

Experienced commercial roofers know that hidden moisture destroys roofs from below.

Testing red flags

• Won’t perform core cuts
  
  
  

• Avoids checking for wet insulation
  
  
  

• Doesn’t inspect structural deck
  
  
  

• Pushes for overlay without testing
  
  
  

• Never mentions infrared scanning
  
  
  

Why this matters

Skipping moisture testing leads to:

• Trapped moisture
  
  
  

• Freeze–thaw membrane damage
  
  
  

• Mold
  
  
  

• Wet insulation
  
  
  

• Deck deterioration
  
  
  

A roofer who avoids testing is setting you up for failure.

Red Flag #8: Poor Communication or Disorganized Operations

Great roofing subs are organized. Amateurs are chaotic.

Communication red flags

• Slow replies
  
  
  

• Unclear scheduling
  
  
  

• No project manager
  
  
  

• No daily updates
  
  
  

• No photo documentation
  
  
  

• Frequent excuses
  
  
  

Why this matters

GCs rely on:

• Predictable timelines
  
  
  

• Clean handoffs
  
  
  

• Consistent scheduling
  
  
  

• Documentation
  
  
  

A disorganized roofer becomes a scheduling disaster.

Red Flag #9: Overpromising Timelines or Guarantees

Inexperienced roofers often say whatever is necessary to win the job.

Common overpromises

• “We can start next week”
  
  
  

• “No leaks ever”
  
  
  

• “We can install in any weather”
  
  
  

• “You don’t need a tear-off; an overlay is fine”
  
  
  

• “We offer 20–30 year warranties” without certifications
  
  
  

Why this matters

When they overpromise, you deal with:

• Delays
  
  
  

• Angry clients
  
  
  

• Warranty disputes
  
  
  

• Budget overruns
  
  
  

• Reputation damage
  
  
  

Reliable subs underpromise and overdeliver—not the opposite.

Conclusion: Spotting These Red Flags Saves GCs Time, Money, and Reputation

Indiana general contractors face enough challenges—tight timelines, weather delays, and demanding clients. You don’t need a roofing subcontractor adding to the chaos.

By learning these red flags and applying them before hiring, you greatly reduce your risk of:

• Costly callbacks
  
  
  

• Schedule delays
  
  
  

• Warranty disputes
  
  
  

• Structural failures
  
  
  

• Angry building owners
  
  
  

The right subcontractor strengthens your business.
The wrong one puts it at risk.

Use this checklist to protect every project, every client, and your reputation across Northeast Indiana.