dryer vent through fire rated wall

Is there any way to get a dryer vent through a one hour rated wall?  This is a Type VB, sprinklered building, the wall is one hour rated due to distance to property line. 2 story building, first floor dryer, the vent wants to be just above the concrete slab.

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A few questions:

1. Residential? If so, single family or apartment or condo?

2. Distance to property line?

3. Wall construction assembly? i.e. int gyp bd, studs w/insulation, sheathing, ext plaster.

4. Is there a plan view & section detail to look at for clarification on conditions?


It is possible if dryer duct termination conditions are:

A. at least 3ft from property line (504.5 Ca Mech Code)

B. duct termination penetration through wall is protected by appropriately listed fire damper. Will require the closing mechanism and shutter to be out of the airstream. CMC prohibits duct items that will catch lint.

C. Somehow you will need to fit a backdraft damper (Ca Energy Code)


Good luck.

When you get this solved, please post details and how you did it.

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