Roofing Code: Chapter 15

Roofs and Roof Structures

Section 1507.2, Steep-Slope Roof Coverings:
Steep-slope roof covering materials and installations shall comply with Section 1507.2.1 through 1507.2.9. In areas where the average daily temperature in January is 25 degrees F (-4 degrees C) or less or where there is a possibility of ice forming along the eaves causing a backup of water, an ice shield that consists of at least two layers of underlayment cemented together or of a waterproofing membrane shall extend from the eave’s edge to a point at least 24 inches (610 mm) inside the exterior wall line of the building.

Code Interpretation:
This code implies that eaves flashing (ice and water shield) is required on all steep-slope structures in temperate climates. Eaves application should be designed in the following manner:

a. Install a single layer of eaves flashing (ice and water shield) over the wood deck.
b. The eaves flashing shall be applied shingle fashion parallel to the eaves and overhang the drip edge by ¼ to ⅜ inches. Apply the eaves flashing a minimum of 3 feet above the interior wall with enough nails to securely hold it in place. The flashing shall be fastened with galvanized roofing nails; staples will not be accepted.
c. All additional layers shall overlap the underlying flashings at least 2 inches. Apply adhesive to the horizontal joint over the entire length of the flashing.
d. Install eaves flashing at all vertical surfaces a minimum of 8 inches up the vertical surface.

Waterproofing Code: Chapter 18

Foundations and Retaining Walls

Section 1813.0, Waterproofing and Dampproofing

Section 1813.4.1, Floors: Floors required to be waterproofed shall be of concrete, designed and constructed to withstand the hydrostatic pressures to which the floors will be subjected.

Code Interpretation:

In buildings subjected to hydrostatic pressure and having a water table that is within 6 inches of the bottom slab, the floors must be constructed of standard concrete. Waterproofing of the slab is completed by application of an approved waterproofing membrane at the bottom of the slab. Joints in the waterproofing membrane shall be lapped and sealed in accordance with the manufacturer’s installation instructions.