pvc dryer vent in slab

[codeworks]

anybody got contractors using pvc (sdr 35 or sched 40) for dryer vents in slabs ? mechanical code says they have to be metal, how about as an :"alternative method". the question was posed to me today, i told the contractor to pass it by the BO.

 

[ICE]

http://www.thebuildingcodeforum.com/forum/residential-mechanical-codes/9662-dwv-under-slab-dryer-duct.html

 

[mtlogcabin]

603.8 Underground ducts.

Ducts shall be approved for underground installation. Metallic ducts not having an approved protective coating shall be completely encased in a minimum of 2 inches (51 mm) of concrete.

603.8.1 Slope.

Ducts shall have a minimum slope of 1/8 inch per foot (10.4 mm/m) to allow drainage to a point provided with access.

603.8.2 Sealing.

Ducts shall be sealed and secured prior to pouring the concrete encasement.

603.8.3 Plastic ducts and fittings.

Plastic ducts shall be constructed of PVC having a minimum pipe stiffness of 8 psi (55 kPa) at 5-percent deflection when tested in accordance with ASTM D 2412. Plastic duct fittings shall be constructed of either PVC or high-density polyethylene. Plastic duct and fittings shall be utilized in underground installations only. The maximum design temperature for systems utilizing plastic duct and fittings shall be 150°F (66°C).

Whirlpool

　

　

　

Consider moisture, lint and air temperature in the design of the central duct system. Maximum exhaust temperature of the dryer will not exceed 200°F (93.3°C) when the dryer is operated according to the instructions provided with the dryer.

We do not allow PVC dryer exhaust at all

 

[Francis Vineyard]

Not approved for dryers but okay to kitchen downdraft ducting.

http://www.thebuildingcodeforum.com/forum/residential-mechanical-codes/9200-under-slab-dryer-vent-2.html

Francis