47.5 MB - The Whole Building Design Guide

E 2112 provides guidance on the design ofsealant joints, as well as other informationpertaining to the installation of windows, includingthe use of sill pan flashings with enddams and rear legs (see Figure 3-39). Windowsthat do not have nailing flanges shouldtypically be installed over a pan flashing. Itis recommended that designers use ASTM E2112 as a design resource.Sealant joints can be protected with a removablestop, as illustrated in Figure 3-40.The stop protects the sealant from directexposure to the weather and reduces thepossibility of wind-driven rain penetration.Where water infiltration protection is particularlydemanding and important, it is recommended that onsitewater infiltration testing in accordance with ASTM E 1105 bespecified.Figure 3-39:View of a typical window sill pan flashing withend dams and rear legsSource: ASTM E 2112Figure 3-40:Protecting sealant with astop retards weatheringand reduces the exposureto wind-driven rain.MAKING CRITICAL FACILITIES SAFE FROM High Wind3-55