8) Do not use sealants that contain materials susceptible to UV light degradation, such as rubber sealants containing chlorinated polymers or acrylates when applied in direct sunlight. If these materials are used, early failure of the EPMB membrane is possible due to premature breakdown of these components under UV exposure.
9) When applying an elastomeric polymer modified bitumen membrane with built-up roof construction, apply a thickened material as the final layer of protection. This will allow a more uniform seal and an added barrier against solar UV degradation.
10) To minimize cracking, increase membrane thickness where low temperatures are expected or in areas prone to high stresses due to wind uplift or mechanically induced forces. The addition of fillers may be required to maintain design thickness above 40°F (-4°C). Fillers should be selected from those recommended by the manufacturer.
11) Any mechanical fasteners used with elastomeric polymer modified bitumen that can cause damage through expansion such as large head screws, stainless steel staples (except clip type), and bolts, should not be used. The expansion force could tear the polymer modified bitumen surface causing premature failure of the entire system. The use of chemically inert fasteners and attachments is recommended, such as fiberglass tape, hot asphalt or modified bitumen fabric underlayment, preformed straps, silicone rubber sealants with a tensile strength exceeding 1,200 psi (8.2 MPa), or heavy duty double-faced tape that can be removed without leaving any adhesive residue on the roof surface.
12) Do not apply an elastomeric polymer modified bitumen membrane to damaged roofs such as those made with asbestos-containing materials unless it has been demonstrated that the damage does not adversely affect either adhesion properties or performance of manufacturing processes specified by the manufacturer.
13) Replace any roof covering portions which become detached from the substrate prior to membrane application. Failure to do so could result in the adhesion system being contaminated by foreign materials which would adversely affect its performance.
14) Do not attempt any repairs to damaged EPMB membranes (e.g., patching holes, fixing rips, etc.) unless it has been specifically recommended by the manufacturer. Repair of minor damage can complicate subsequent field inspection and quality control procedures required for compliance with applicable codes later standards. If removal and impossible, perform a factory-approved repair process on the defective area(s) prior to reinstalling a new layer of EPMB over top of the old material.
15) Ease mold release agents are used when removing cured elastomeric polymer modified bitumen from forming rollers and tools. If these materials are used, the adhesive forces will be reduced resulting in a weakened bond to the substrate.
16) Remove any water that has been absorbed by the elastomeric polymer modified bitumen membrane from storage before application to prevent premature breakdown of the system as well as blistering of the finish coat(s).
17) Elastomeric polymer modified bitumen is not recommended for use in wall panel joint and lap joints or exposure conditions exceeding 140°F (60°C).
18) Do not apply elastomeric polymer modified bitumen on roof surfaces with excessive air movement due to its susceptibility to wind induced loose-laid shingle problems or wrinkling when applied below 40°F (-4°C).
19) Voids (e.g., spalled, shingles, flashings, improper valley installations) which are not properly filled prior to elastomeric polymer modified bitumen application will cause premature and costly membrane failure.
20) Elastomeric polymer modified bitumen cannot be applied over a previously coated surface until all curing has been completed or the coating is otherwise protected from UV degradation. If left exposed it may then adversely affect the adhesive properties of the new layer of EPMB causing cracking or increased susceptibility to weathering. It also may degrade paint coatings resulting in 'bleedthrough' that is visible through the black granular appearance of the surrounding areas of the coating system and often identified as a 'bullseye' effect.
21) Do not use elastomeric polymer modified bitumen membranes on thick (>60 mil [1.52 mm]) roofing underlayment or roofing felt. This is because these materials lack the durability and puncture resistance required to withstand normal environmental challenges (air, moisture, sunlight, etc.) in addition to the stresses placed upon it when walking on them during installation of subsequent layers of membrane system components. Normal maintenance activities will also create voids which will cause premature failure of the EPMB if used below 60 mils (1.52 mm). Thinner underlayments made with a higher density polyethylene such as those specified for use with torch applied coatings are recommended instead.
22) Elastomeric polymer modified bitumen membranes should not be subjected to temperatures above 140°F (60°C), as this temperature can adversely affect membrane properties and cause premature failure. Avoid using this material under conditions that will likely result in excessive air movement or radiant heat exposures of roofing assembly elements, such as asphalt shingles or standing seam metal panels which are difficult to secure properly.
23) Elastomeric polymer modified bitumen membranes should be confined to use on flat or simple sloped roofs with slopes less than 4:12 (2%) where the pitch is not too steep for safe application by hand layering and adequately protected from punctures during subsequent field finishing operations without the use of mechanical equipment. Metallic fasteners such as nails and staples should never be used with EPMB. Nail heads can cause surface indentations/lacunae in the material due to a combination of air pressure forces while the substrate is being installed, UV degradation from sunlight reflecting off of them during service, and secondary exposure to mold release agents. Staples can puncture the membrane and cause premature failure.
24) All mechanically fastened roofing systems must have a water-resistive barrier applied directly above or below, as detailed in Section 301.4 of the 2009 IECC.
25) Elastomeric polymer modified bitumen membranes should not be used on roofs that are subjected to vehicle traffic loads prior to qualified field testing/installation using equipment that is specifically designed for handling and applying elastomeric polymer modified bitumen (e.g., special air/water blowers). These specialized procedures may be required where site conditions or other concerns indicate potential problems with adhesion of mechanically fastened products (e.g., flashing, nail heads, joint and valley details), seaming, mechanical fasteners (e.g., staples), membrane resistance to puncture by UV degradation from sunlight reflections off of the metal surfaces, or where site conditions are beyond the capabilities of a typical roofing installer.
26) Avoid pinchweld areas of standing seam roofing system if possible. If you must use EPMB in this application either try to separate the areas where these seams will go apart or wrap all exposed materials with sheet goods. With proper separation seam sealing is not required but seams can still be sealed if desired.
27) In multi-wythe applications, elastomeric polymer modified bitumen membranes should not be installed over existing eavestroughs until after the membrane covering the adjacent wall area has been applied.
28) Elastomeric polymer modified bitumen membranes for commercial roofing maintenance
should not be used in areas where they will be subjected to continuous direct exposure to sunlight. Exposed membrane edges and seams must be protected from UV degradation using tape or paints that are designed for this purpose.
29) Elastomeric polymer modified bitumen has a limited ability to resist punctures caused by nails and staples, which can compromise the entire roofing assembly and lead to premature failure of the waterproofing layer. Nails with polyethylene inserts instead of external plastic coating are recommended over galvanized roofing nail types for use on EPMB. External plastic coatings should never be applied over sheets containing metallic fasteners, as these will cause damage to the coating during service.
30) To prevent premature membrane failure and damage to the building substrate, EPMB should not be installed over existing roofing materials (except mineral-surfaced roll roofing, or if the existing roof covering is ice barrier material that will be fully covered by EPMB).
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