Q1: I sometimes specify the use of torch-applied polymer-modified bitumen roof systems. What is CERTA and how does
it apply to me?
A1: CERTA is the roofing industry's certified roofing torch applicator program. It was developed in response to
increasing fire losses in the roofing industry. CERTA is a safety program that establishes best practices in the design
and application of torch-applied roof systems and use of a roofing torch.
CERTA also is a requirement for roofing contractors who use roofing torches as a condition of general liability
coverage by some insurance companies.
Q2: What are the CERTA new industry best practices?
All flashings, curbs and penetrations that incorporate combustible components, such as wood nailers or wood fiber
cant strips, must be encapsulated with multiple base ply sheets before the installation of torch-applied materials.
When applying torch-applied, polymer-modified bitumen sheet products as membrane flashings over combustible flashing
substrates, a two-layer backer shall be incorporated into the detail design and installation. Acceptable two-layer
backers include a layer of a fiberglass base or ply sheet mechanically fastened to the combustible substrate and an
additional layer of a fiberglass ply sheet adhered to the first layer using solid moppings of hot asphalt.
When applying torch-applied, polymer-modified bitumen sheet products over combustible roof deck substrates
without above-deck thermal insulation, a thermal barrier shall be incorporated into the roof system design and be
installed over the roof deck before the installation of the polymer-modified bitumen membrane system. Acceptable
thermal barriers include 3/4-inch-thick perlite board insulation; 3/4-inch-thick fiberglass insulation board; or
1/4-inch-thick glass-faced gypsum board. When a layer of noncombustible insulation is used as the thermal barrier,
the roof system shall be considered an "insulated substrate" and comply with the manufacturer's recommendations and
the specific recommendations for insulated substrates contained in the current edition of the NRCA roofing and
All flashings at penetrations, curbs, walls, parapets, edges, etc. MUST be installed using the torch-and-flop
method. The flashing pieces must be precut; heated on a noncombustible surface away from the area to be flashed; and
flopped into place by hand. An open flame should NEVER come in direct contact with any flashing areas, penetrations
or roof edges.
Q3: Are peel-and-stick products approved as an encapsulating base ply for flashing applications?
A4: Yes, provided they include a base layer of either a nailed fiberglass base ply or additional layer of
Q4: Are base plies that are fully adhered in cold-applied asphalt-based mastics, cements or adhesives approved as an
encapsulating base ply for flashing applications?
A4: No. Asphalt-based mastics, cements or adhesives are not approved for torch-applied flashing materials.
Q5: I have heard using torch-and-flop application techniques for flashing and detail areas is more difficult and
results in a poorer quality installation. Is this true?
A5: No. Great quality applications can be achieved using the torch-and-flop method. This technique is an acquired skill
and requires practice. Many roofing workers are not accustomed to using torch-and-flop exclusively and they will need
to practice and acquire this new skill. Many roofing contractors already use torch -and-flop methods exclusively and
have had good experiences. It is possible to achieve a quality installation using torch-and-flop methods.
Q6: Can I hire roofing contractors whose employees are not CERTA trained?
A6: Roofing contractors whose employees are certified under the NRCA/MRCA CERTA program are your best bet to avoid a
catastrophic fire. You should be aware that some insurance companies, building owners, military bases, general
contractors and local building code authorities require CERTA-certified roofing mechanics as a contract
Q7: Where can I find more information about the NRCA/MRCA CERTA program and the new industry best
A7: Additional information about the NRCA/MRCA CERTA program can be found in a student manual or an authorized
trainer's instructor's guide.
For more information, click here, or contact Janice Davis, NRCA's
manager of education and risk management, at (847) 299-9070, Ext. 7505, or firstname.lastname@example.org.