(Spec. ID)-C2 Squeegee Method. CSI 3-Part Specifications. Large file (>500kB).

Squeegee Method

Two-Part Cold Adhesive SBS Modified Bitumen Roofing System (Refer to the hot mopped membrane specification for diagram.) For use as an alternative application method to hot asphalt applied SBS modified bitumen membrane specifications.

For Regions 1, 2 and 3

The adhesive is applied at a rate of approximately 1 to 2 gallons per square over non-porous substrates, e.g., primed concrete or fiber glass base felts. If over porous materials, such as insulations, the application rate will increase to approximately 2 to 3 gallons per square or more depending on the absorbency of the material.

General

This specification employs a cold adhesive, JM MBR Bonding Cement, as a direct substitute for the Type III and IV asphalts used in hot application of modified bitumen roofing specifications. JM does not recommend the use of traditional asphalt cutback cements and mastics to bond SBS products to any substrate. MBR Bonding Cement is a two component, elastomeric adhesive, consisting of a base material and an activator. It is ideal for applications where hot asphalt is undesirable or prohibited.

This specification is intended to be used over JM roof insulations or other approved roof insulations which are not nailable and which provide a suitable surface to receive the roof. Specific written approval is required for any roof insulation that is not supplied by JM. This  specification may also be used over any type of approved structural deck which provides a suitable surface to receive the roof. Poured and pre-cast concrete decks require priming with JM Concrete Primer. The primer must be completely dry before adhesive application begins.

Note: All general instructions contained in the current JM Commercial/Industrial Roofing Systems Manual shall be considered part of this specification.

Design and installation of the deck and/or membrane substrate must result in the roof draining freely, to outlets numerous enough and so located as to remove water promptly and completely. Areas where water ponds for more than 24 hours are unacceptable and will not be eligible for a JM Roofing System Guarantee.

Flashings

Flashing details can be found in the "Bituminous Flashings" section of the JM Commercial/Industrial Roofing Systems Manual.

Application

On roof decks with slopes up to 1/2" per foot (41.6 mm/m), the roofing felts and modified bitumen sheets may be installed either perpendicular or parallel to the roof incline. Follow the specific felt lay-up prescribed in the hot asphalt version of the desired specification. 

JM MBR cement products are significantly different from the adhesive materials used for built-up roofing. The mechanic must use a great deal more care since these adhesives are prepared on the job site. Roofing contractors must advise their crews to precisely follow all  storage, handling, preparation, application, and health/ safety instructions. JM will not accept responsibility for any use of these products that does not comply with the instructions printed on the cement base container.

For specific and detailed information on the mixing and application of MBR Bonding Cement, and the construction of this specification, refer to Paragraphs 7A.14 - 7A.25 in the current JM Commercial/Industrial Roofing Systems Manual.

Surfacing

Refer to the appropriate hot application specification.

A heavy coating of adhesive may be applied over smooth surfaced products. Roofing gravel or granules may then be embedded in this coating.

If reflective coatings are to be applied to smooth surfaced, modified bitumen sheets, make certain that any residual adhesive bleedout at the laps has been removed and the area is completely dry. Bleedout material may impede adhesion or cause staining of the reflective coating. The coating is to be applied in accordance with the manufacturer�s application instructions.