(Curb Mount Base)
SDF-20CM (Curb Mount Base) is designed for curb mount installations. Generally a 2"x4" or 2"x6" curb box is built and flashing is attached to the perimeter of the curb box. Curb mount installations should be used on flat or very low slope roofs. Curb mount installations are also recommended for higher profile roofs, such as ceramic or concrete tile, certain metal roofs, thick wood shake, etc. The flashing materials are generally metal, but can be made of certain types of roofing materials. Care should be taken to isolate dissimilar metals and to properly waterproof the curb box to the roof.
MAXIMUM OUTSIDE CURB DIMENSION SHOULD BE NO LARGER THAN 16" X 19-1/4" TO ALLOW FOR PROPER FLASHING. IF MORE CLEARANCE IS NEEDED REDUCE CURB SIZE ACCORDINGLY.
CIRCULAR OPENING AT BASE--13-3/8"
On top of the curb box, attach weather stripping or two sided foam tape. Place the SDF-20CM base on top of the curb box and fasten at least two screws on each side into the curb box.