|
Introduction |
1.4.6 Study all plans to determine whether different roof areas have different requirements (thickness or type of insulation, changes in roof
membrane, vapor retarder, etc.).
1.4.7 Designate which areas on the site will be available for use as storage areas and working areas. Roofing materials must be properly
protected. Consideration should be given to the effects of the roofing operation on the occupants of the building. These include placing the
asphalt kettles away from windows, doors, and air intakes, closing of building air intakes in the construction area, and advising the occupants.
1.4.8 Review the procedures to be followed to provide proper protection of the roofing system during and after construction of the roof. This
should include protection procedures to be followed by any construction trades that have access to the roof.
1.4.9 The pre-roofing conference and inspection shall serve to clarify all specifications, details, application requirements and any work that
should be completed before the roofing operation can begin.
1.5 JM Approved Roofing Contractors
1.5.1 JM does not construct commercial/industrial roofs, nor do we own an interest in any firm that does. Thus, except under the terms of a
Guarantee, we cannot be responsible for any roofing contractor’s workmanship.
1.5.2 We do maintain a list of contractors, called JM Approved Roofing Contractors, who are eligible to construct and to repair JM guaranteed
roofs. THE NAME "JM APPROVED ROOFING CONTRACTOR" MERELY IDENTIFIES AN INDEPENDENT CONTRACTOR CONSIDERED
ELIGIBLE TO APPLY FOR A JM ROOF GUARANTEE AND IN NO WAY DESIGNATES HIM AS AN AGENT FOR JM.
1.6 Test Cuts
1.6.1 JM opposes judging a roof's compliance with specifications solely by analyzing a test cut. Failure of small samples to exactly meet a
specific property standard could require rejecting the entire roof regardless of extenuating circumstances. Such a judgment ignores variables
that the roofing mechanic, using generally accepted techniques and equipment, cannot control.
1.6.2 Good distribution of asphalt in a continuous layer, firmly bonding the felts, is far more important to serviceability of roofing membranes
than total weight of asphalt. Roofers who fear that a test cut may show too little asphalt may use excessive asphalt and produce a roof prone to
sliding even on low slopes.
1.7 Conditions of Test Cuts
1.7.1 When it is determined that a test cut is necessary to confirm construction details, analyze unexplainable situations, or satisfy other
demands not readily apparent by surface observations, for JM Guaranteed roofs, JM should be notified prior to cutting into the membrane, in
order to identify any specific procedures or limitations which might be relevant to the particular installation.
1.7.2 When test cuts are taken from either an old or a new BUR or modified bitumen roof, they shall be 6" x 45" (152 mm x 1143 mm), at right
angles to the length of the felts, if the roof membrane construction is of interest. Such samples are more meaningful than 12" x 12" (305 mm x
305 mm) samples because they reveal whether the base felt (if present) was properly lapped, and the ply felts laid with the proper exposure.
For a 6" x 45" (152 mm x 1143 mm) roof cut, the average weight of the test cut components should be within ±20% of specified values except
for interply asphalt which is ±25% (these ranges are consistent with those outlined by NRCA). A 12" x 12" (305 mm x 305 mm) roof cut can be
useful for determining the amount of asphalt used on a BUR or modified bitumen roof, if proper consideration is made for the small sample
size.
1.7.3 Repair all test cuts with the same materials and techniques used to construct the original roofing membrane.
1.7.4 JM reserves the right to cancel a Roof Guarantee if test cuts are taken without prior written approval.
1.7.5 JM believes visual inspection of the roofing system during its construction is a much more valid way to evaluate the quality of a roof than
by taking roof cuts.
1.7.6 This visual inspection shall be conducted by a knowledgeable person to determine that the roof was installed according to specifications
and good roofing practice, as given below and on the next page.
1.8 General System Recommendations
1.8.1 For All Roofing Systems:
A. |
The deck is installed in accordance with the architect’s and deck manufacturer’s specifications, and the guidelines outlined in the
deck section of this manual. |
B. |
All roofing materials comply with the project specifications and approvals. |
C. |
The insulation is properly secured to the substrate. |
D. |
The proper number and type of mechanical fasteners are used to secure the roofing membrane, if required. |
E. |
All flashing materials are installed according to the approved specification. This includes proper nailing, stripping and
counterflashing. |
F. |
All components of the roofing system, including expansion joints, metal flashings, gravel stops, etc., are installed according to the
approved specifications. |
G. |
The roof system is installed in compliance with the proper insurance and/or code requirements. |
H. |
Proper water cutoffs are installed at the end of each day’s work and removed before the start of the next day’s work. |
