01 May 1999
be discussed (if called for). The membrane and flashing must be completed in decent weather.
Installation of insulation, filter fabric, and ballast may be done in inclement weather.
c. Shop Drawing Submittals. Drawings for the membrane and flashing system should be
provided with special attention to base-of-walls and curbs. If interlocking pavers are used, show
details of strapping/ballasting where interlock is missing. Filter fabric should cover insulation and
be turned up the raised curb at least 25 mm (1-in.). A certification should be furnished indicating
the supplied insulation, filter fabric, and membrane meet the supplier's specifications for a
warranted PMR system.
d. Field Review and Observation.
(1) Insulation Storage.
Verify the insulation is protected against sunlight and open
(2) Insulation Installation. Insure the installed insulation remains unadhered. Use
slipsheets if the substrate is tacky or contains coal tar pitch. Drainage channels shall run parallel
e. Design Submittal Requirements and Checklist. The PMR system should be provided by
the contractor as a complete system. The same manufacturer should supply the membrane and
3-5. MAINTENANCE CONSIDERATIONS.
a. General. Unprotected flashings are as vulnerable to damage as any other system. Wind
scour or membrane lifting can cause displacement of ballast. Heavier ballast may be needed at
the perimeter and corners (ANSI/SPRI RP-4).
b. Repair or Replace. Since insulation, filter fabric, and ballast are not adhered, they are
reusable. To lift interlocking lightweight pavers it may be necessary to use a saw to cut off the
tongue of a few pavers. Upon replacement such pavers can be strapped together with non-
rusting sheet metal and fasteners or held in place with an overlying layer of heavy pavers.
Repairs: Emergency, Temporary, and Permanent.
(1) Emergency repairs would involve removing ballast, effecting repairs and replacing
the system. Do not reinstall XEPS over fresh solvent-containing mastic until all solvent has
(2) Temporary repairs might involve sandbags or dunnage to keep a wind disturbed roof
in place until permanent repairs can be made.
(3) Permanent repairs--See ANSI/SPRI RP-4 for ballasting guidelines.
d. Repair Work by User. Repairs to the membrane and flashing would follow what is
appropriate for that particular membrane system. Broken corners of interlocking cement-topped
insulation can be repaired by filling in with latex-modified cement or by coating exposed XEPS
with latex paint to retard UV degradation. Replacing damaged units may be better.
e. Maintenance Checklists.
(1) Visual Observation. Inspect the roof surface after precipitation to verify that the roof