Vinyl Siding Soffit

The popular use of the word “soffit” most often refers to the material from the top, exterior, house wall to the outer edge of the roof, otherwise known as the eaves. Soffit exposure profile on a structure can range from 2 or 3 inches to beyond 3 or 4 feet depending on the structure. It can be vented for cooling unfinished attic space or no venting. Any homeowner with basic skills can install a vinyl siding soffit, typically in conjunction with covering the entire structure. Vinyl is one of the most popular exterior building materials with new construction and with existing structure renovations because it’s relatively inexpensive, convenient and very attractive.

Vinyl siding soffit material is a different product than other siding but installation is basically the same. The first step is installing the trim. If framing already exists, you use J-channel to hold the ends of the soffit along the structure as well as along the short sides of the soffit. If there is no framing you use F-channel along the structure. The soffit panels slip into the trim and are nailed into the sub fascia with short trim nails. The end along the structure will sit loosely in the F or J channel. If the soffit is too wide, it may be necessary to add additional support pieces down the middle and nail the soffit panels into those to avoid sagging.

Once the soffit is in place, you finish the job by installing fascia to cover the outside edge and to protect the sub fascia. The top edge of the fascia is held in place with a piece of under sill trim, or hidden behind a piece of drip edge or other flashing. The top of the fascia may need to be trimmed in order to fit between roof and soffit.