Direct Answer
A fastener pull-out test is a field test that measures how much force is required to withdraw a roofing fastener from the roof deck or substrate. Commercial roofing professionals use the results to evaluate whether the deck can adequately hold the fasteners used to secure insulation, cover boards, base sheets, or mechanically attached roofing membranes.
For Florida commercial roofing projects, the number of tests depends on the applicable testing standard, roof area, deck material, roof assembly, and project specifications. Under the commonly referenced Florida TAS 105 schedule, roofs measuring 100 roofing squares or less require 10 withdrawal-resistance tests. Three additional tests are required for every additional 50 squares, with increased sampling for certain deck types. Always verify the requirements applicable to the specific project before testing.
Fastener pull-out testing is particularly important during reroofing, when the existing deck’s holding capacity may be uncertain. The results help the roofing designer determine whether the proposed fastening arrangement can provide the required resistance to wind uplift.
Who This Applies To
- Commercial property owners
- General contractors and roofing contractors
- Developers and construction managers
- Roof consultants and registered roof observers
- Property and facility managers overseeing reroofing
- Owners replacing mechanically attached commercial roofing systems
- Project teams evaluating existing roof decks before installation
Not for: This guidance does not replace project-specific engineering, approved roof-system requirements, or the applicable building code and testing standard.
1. What Does a Fastener Pull-Out Test Measure?
The test measures the withdrawal resistance of a fastener installed into a particular deck or substrate. A calibrated pull tester applies tensile force to the fastener and records the load at the specified failure point.
The test helps establish whether the fastener-and-deck combination can provide sufficient holding strength for the proposed roofing assembly.
Results can vary depending on:
- Deck material and thickness
- Deck age and condition
- Fastener type and diameter
- Installation depth and technique
- Pilot-hole diameter where applicable
- Moisture damage or deterioration
- Variations in the substrate
For additional technical background, review the ANSI/SPRI FX-1 field test procedure.
2. Why Is Pull-Out Testing Important?
Mechanically attached roofing systems depend on fasteners holding securely in the underlying deck. If the deck cannot provide sufficient withdrawal resistance, the completed roof may not achieve its intended attachment performance under wind loading.
Testing is particularly useful when:
- An existing commercial roof is being replaced.
- The existing deck’s specifications are unknown.
- The deck has deteriorated or sustained moisture damage.
- A new roof system requires a different fastener arrangement.
- The project involves high-wind design requirements.
- The roofing manufacturer or design professional requires field verification.
Pull-out testing is one input into the attachment design. It does not, by itself, certify that the entire roof assembly meets all wind-uplift requirements.
3. How Many Fastener Pull-Out Tests Are Required?
The required quantity depends on the applicable standard and project conditions. For Florida projects using the commonly referenced TAS 105 schedule, the following quantities are generally cited for field withdrawal-resistance testing:
| Roof Area | Commonly Cited Minimum |
|---|---|
| Up to 100 roofing squares | 10 tests |
| Each additional 50 squares | 3 additional tests |
| Gypsum, lightweight insulating concrete, or cementitious wood-fiber decks | Increased sampling may be required |
One roofing square equals 100 square feet. Therefore, 100 squares represent 10,000 square feet.
For the commonly cited schedule, a 150-square roof would generally start with 13 tests, while a 200-square roof would generally start with 16 tests, subject to the applicable TAS 105 requirements and any project-specific provisions.
For authoritative project verification, consult the applicable Florida Building Code testing protocols and the testing standard specified for the project. TAS 117(A), for example, addresses laboratory withdrawal-resistance testing of mechanical fasteners and is not interchangeable with every field-testing requirement.
4. Where Should the Tests Be Performed?
Test locations should represent the roof areas and conditions that matter to the proposed attachment design. Under the commonly cited Florida TAS 105 schedule, the initial 10 tests for roofs up to 100 squares are distributed among the roof field, perimeter, and corner areas, with at least three tests in perimeter areas and three in corner areas.
Testing may also need to account for:
- Different roof-deck materials
- Separate roof sections
- Different roof elevations or assemblies
- Areas affected by leaks or suspected deck damage
- Areas with inconsistent or questionable substrate conditions
The applicable standard and project specifications determine the final sampling plan. The tester should record each test location on a roof plan.
5. How Is a Pull-Out Test Conducted?
- Review the roof assembly: Confirm the deck type, proposed fastener, and applicable testing procedure.
- Prepare the test location: Expose the substrate as required by the standard.
- Install the fastener: Use the specified fastener and appropriate installation method.
- Attach the tester: Connect a calibrated withdrawal-resistance testing device.
- Apply tensile force: Load the fastener according to the applicable procedure.
- Record the result: Document the measured withdrawal resistance and test conditions.
- Map the location: Identify the test number and location on the roof plan.
- Review the findings: Provide the results to the responsible roofing designer or qualified professional.
The testing equipment must meet the applicable calibration and accuracy requirements. The test report should document the fastener, substrate, test location, measured load, and other information required by the governing procedure.
6. What Happens If the Test Results Are Too Low?
If the measured withdrawal resistance does not support the proposed attachment design, the roofing team may need to revise the design before installation.
Potential responses include:
- Using an alternative approved fastener
- Increasing fastener density where the engineered design permits
- Changing the attachment pattern
- Repairing or replacing deteriorated deck material
- Evaluating a different approved roofing assembly
- Performing additional tests to understand inconsistent results
The appropriate response depends on the measured values, design loads, deck condition, manufacturer requirements, and engineering review. Do not independently change fastener spacing without approval from the responsible design professional and confirmation that the revised assembly complies with applicable requirements.
7. Do Different Deck Types Require Different Testing?
Yes. Steel, wood, structural concrete, gypsum, lightweight insulating concrete, and cementitious wood-fiber decks can have different testing procedures and sampling requirements.
For example, some deck materials require different loading rates or additional samples because their properties and test variability differ. The governing procedure should be selected for the actual substrate rather than applying one universal test method to every roof.
The Florida Building Code TAS 117(A) protocol illustrates how testing requirements can vary by substrate and laboratory test conditions.
8. What Should the Final Test Report Include?
A useful report should contain enough information for the roofing designer and project team to evaluate the results.
- Project and building identification
- Roof plan with numbered test locations
- Roof-deck type and relevant condition observations
- Fastener type and installation details
- Testing equipment and calibration information
- Individual test results
- Required calculations and statistical information
- Identification of unusual or inconsistent results
- Recommendations or follow-up requirements, where applicable
- Required signatures and approvals
The final report should follow the applicable standard and be provided to the responsible design professional or other designated project representative.
9. When Should Testing Be Scheduled?
Pull-out testing should generally be completed early enough for the results to inform the roof attachment design before installation begins. On reroofing projects, testing can help identify deck limitations before materials and labor are committed to an unsuitable fastening arrangement.
Coordinate the testing schedule with the roofing contractor, manufacturer, consultant, and design professional. If testing reveals insufficient or inconsistent resistance, allow time for additional testing, engineering review, or design changes.
Bottom Line
A fastener pull-out test measures the withdrawal resistance of a roofing fastener installed into a specific deck or substrate. It helps determine whether the proposed mechanical attachment can provide the holding strength required by the roofing design.
For projects using the commonly cited Florida TAS 105 schedule, the initial quantity is 10 tests for up to 100 roofing squares, plus three tests for each additional 50 squares, with increased sampling for certain deck types. However, the exact requirement must be confirmed against the applicable standard, approved roof assembly, manufacturer requirements, and project specifications.
Related Questions
- What Does a Commercial Roof Observation Report Include?
- What Is a Pre-Installation Roofing Conference, and Why Does It Matter?
- What Does a GC Need to Know About Manufacturer Warranty Inspections on a New Commercial Roof?
Sources
- ShieldLine Roofing — What Is a Fastener Pull-Out Test and How Many Tests Are Required?
- ANSI/SPRI FX-1 — Standard Field Test Procedure for Determining the Withdrawal Resistance of Roofing Fasteners
- Florida Building Code — TAS 117(A), Withdrawal Resistance Testing Protocol
- GenFlex — TPO Metal Building Retrofit Guide
Last reviewed: October 2026
Need Commercial Roofing Help?
ShieldLine Roofing can help commercial property owners and project teams evaluate roof attachment requirements, coordinate appropriate testing, and determine the next steps when existing deck conditions affect a proposed roofing system.
Disclaimer: This information is for general educational purposes and is not engineering, building-code, or installation advice. Testing quantities and procedures vary by jurisdiction, substrate, roofing system, and project specifications. Confirm requirements with the applicable building official, testing agency, roofing-system manufacturer, and qualified design professional.
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