MIL-HDBK-1001/SA
d) Expansion joints and/or control joints;
e) Structural adequacy or load-bearing capacity in conformance to current design criteria;
f) Deterioration of parapet walls and/or adjacent step-up walls.
10.3.2 Interior Space Conditions. Psychrometric factors to be considered include the following:
a) Building occupancy (current and proposed);
b) Existing building heating, ventilating, air conditioning, and humidification systems;
c) Maximum hour location of dew point within the roof composite;
d) Vapor retarder requirements. Be aware of vapor pressure direction in humid climates which is usually downward.
10.3.3 Topside Deficiencies
a) Design;
b) Materials;
c) Workmanship.
10.4 Design Considerations. The most basic design decision in reroofing is to either recover or replace. Always use nondestructive testing before designing. A leaking roof which is classified as a premature failure must be evaluated for potential contributions to the failure (refer to par. 10.3). Never recover even a partially water-saturated insulation-membrane system. If the roof has been recovered once, a second recovering is not allowed. Design options are either recovery or replacement. Consider all options for best choice.
10.4.1 Drainage. Adding slope will eliminate the major cause of premature roofing failure. However, on some existing low slope decks it is costly or impractical to create a 1/2-inch per foot (4 percent) slope with tapered insulation. Where existing low slope or near level roofs have failed due to old age and not
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