Size Tolerances for Installation of Fan-Tastic Vent Roof Vent FV802250

Question:

I have a 14inch X 14inch vent with a white plastic dome cover. The existing opening is a 14inch between beams X 14¾inch Spacing between sides. All the vents ask for a 14¼inch X 14¼inch rough opening. I expect that has tolerance for setting the unit squarely in the opening. The tight dimension is one which I am reluctant to trim. Will the FV802250 work in the width? It looks like a small flange I should have at least 16inch between screw centers to catch both side supports, is this possible? You can see the original installation was sloppy and one side was missed. This however is relatively easy to pack-out. My main question is what tolerance is allowed for the rough opening size versus physical dimensions of the outside of the fan housing?

asked by: Bill K

Expert Reply:

The 14-1/4 x 14-1/4-inch rough roof opening required for most trailer roof vents like # FV802250 does allow for a bit of leeway in most installations. I have not heard of an existing trailer vent opening not allowing for installation of a replacement fan/vent unit. Certainly if a particular trailer was produced with looser tolerances it could happen that a "correct" vent might not fit ideally right out of the box. However, since your original vent appears to be an industry-standard type I expect you will not have an issue installing a replacement like the Fan-Tastic Vent Roof Vent # FV802250.

To install this on a metal roof use kit # CAM25003.

expert reply by: Adam R