01 May 1999
l. Penetrations. Periodic inspections and repairs are required for penetrations. Pitch pockets
must be periodically refilled to function properly.
m. Historical Roof Restoration. Buildings of historical significance should be repaired with matching
(not necessarily identical) materials to maintain their original appearance.
n. Aesthetics. When the appearance of a built-up roof system is not an issue it is sometimes best
not to reapply aggregate to patches for at least a year or so. On future inspections the patch can be
easily found and examined for integrity.
o. Gaps, Flashings, Joints, and Sealants
(1) Sealants. Exposed sealants such as at termination bars and laps of some single-ply systems
may need rework due to deterioration. Protected sealants, such as the butyl, used where two metal
sheets lap deteriorate very slowly.
(2) Joint Covers. Splices of elastomeric expansion joint covers may disbond with aging. Where
shrinkage or movement has caused a joint cover to collapse, crack, or tear consider installing a wider
p. Drainage, Valley and Intersection Details.
(1) Maintaining Proper Drainage. Roof drainage systems are discussed in detail in Chapter 1 of
the SMACNA Architectural Sheet Metal Manual. Roof drains must be kept free of debris in order to
function. Overflow provisions are essential since the primary drains may become blocked.
(2) Pressure Washing. On steep roofing systems such as wood shakes, periodic pressure
washing to remove silt and pine needles from between individual shakes and at flashings is beneficial.
(3) Rusting. Galvanized sheet metal will rust when the zinc coating erodes. Recoat exposed
12-3. DESIGN CONSIDERATIONS FOR ROOF MAINTENANCE.
a. Roof Traffic. Provide access, railings and traffic-ways as needed.
b. Low Maintenance Details. Avoid pitch pockets and other details that require periodic service to
perform properly. Avoid embedded metal gravel stops at membrane level in bituminous systems. (See
NRCA recommendations and construction details.)
c. Periodic Inspection. Establish inspection and maintenance protocols. Use ROOFER or a similar
system to record inspections and repairs and to program future work.
12-4. CONSTRUCTION CONSIDERATIONS.
a. General. Roof membranes are relatively fragile elements and are easily damaged by other
construction trades. Controlled access to the roof is extremely important.
b. Pre-roofing Conference (new construction or reroofing). An agenda item should include
protection of adjacent roofing and the newly constructed roofing from damage by other trades.