SWS Detail: 5.0501.1 Isolate CAZ
Author: Turner
CAZ exposed to interior
CAZ isolated from building envelope
Follow work orders to isolate the CAZ
Use standard stick framing practices to build partitions.
Minimum clearances to combustion appliance in the new space must be maintained. (IRC M1306)
Minimum clearances to combustion appliances in the new space must be maintained (IRC M1306).
A level working space not less than 30 inches deep and 30 inches wide shall be provided in front of the control side to service an appliance with the door open. (IRC M1305).
Use rigid materials and sealants to complete the air barrier on all sides, top and bottom of CAZ.
Finish surfaces only to establish an air barrier.
See Combustion Air (Exterior) to install or repair properly sized combustion air openings.
Follow instructions in Insulation Sections to install or complete the thermal barrier on all walls ceilings and floors that are adjacent to the conditioned space.
A properly isolated CAZ will have an insulated door that is air-tight.
The opening must allow for minimum access to equipment located in the new CAZ. (IRC M1305.1.1)
Follow instructions in Air seal Windows and Doors, or Door Install to seal or replace CAZ door when door is on wall between CAZ and building envelope.
Follow instructions in Air Seal Duct section to seal all duct work inside CAZ both supply and return ducts.
Follow instructions in Duct Insulation section to ensure all duct inside the CAZ is insulated.
Follow instructions in DWH Pipe Insulation to insulate all waterlines inside the CAZ to prevent freezing.
Conduct a Zonal Pressure test to determine how isolated the CAZ is. Complete isolation is not required, but the goal is to separate the CAZ as much as possible.
As a best practice a ZPD of 45pa WRT house while house is decompressed to -50 is recommended.
Conduct a Worst Case draft test to verify Category I, II and III appliances are venting safely before leaving home for the day.
Testing shall be recorded using the Utah WAP Worst Case Draft Test form.
Educate the client on purpose and operation of Isolated CAZ.