Technical FAQs
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?
A2:
Click here to view a detailed list
of the new industry best practices. Although you need to be familiar with all of
these new best practices, roof system design professionals specifically need to
be familiar with the following information:
- 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 waterproofing manual.
- 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.
Click here to view the entire list of new best
practices.
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 peel-and-stick material.
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
condition.
Q7: Where can I find more information about the NRCA/MRCA CERTA program and the new
industry best practices?
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
jdavis@nrca.net.