FEMA 453 Design Guidance for Shelters and Safe Rooms

m Penetrations. Measures for reducing air leakage through
penetrations are as follows:
m Seal penetrations for pipes, conduits, ducts, and cables
using caulk, foam sealants, or duct seal.
m Place weather-stripping (including a door sweep) on
the door(s) of the safe room. If the selected room is a
bathroom, and there is a supply duct but no exhaust
duct, the door sweep may be omitted because it would
reduce the supply flow rate in normal use. In this case,
duct tape can be used to seal the gap beneath the door
temporarily in an emergency. If there is carpeting in
the safe room, a door sweep may be more effective
than tape. There may be louvers in the door for return
airflow, but they should not be modified to ensure
proper ventilation can be maintained in normal
conditions. Door louvers should be expediently sealed
as described in Section 3.4.1.2.
m Windows that are old and/or in poor condition
can allow substantial leakage; however, newer,
non-operable windows are not likely to require
any sealing. Window leakage can be measured
using a blower door to determine whether window
replacement or sealing measures are necessary. In
some cases, the leakage of windows, such as poorly
maintained sliders, can be reduced only by replacing
them or by using expedient sealing measures such as
taping plastic sheeting over them.
m Expanding foam can be used to seal electrical outlets
and switches. Also, ready-made outlet sealers can be
used to seal gaps behind switches and outlets.
3.4.1.2 Preparing for Rapidly Sealing the Room. The selected safe
room may have one or all of the following intentional openings,
which are necessary for normal operation. The openings must be
CBR ThReaT pRoTeCTion
3-