As for the purpose of the trim it protects the fascia board from harsh weather and also makes your roof look better.
How to install vinyl siding fascia.
How to install vinyl soffit fascia step 1.
Install lengths of j channel along the inner edge of the fascia.
The first step you should take involves removing the gutter from the fascia where you plan to install the trim.
Vinyl soffit and fascia installation guide open eave installation.
Measure and cut the soffit.
J channel on inside wall and behind fascia board fig.
Nail j channel pieces under the fascia.
Remove any existing soffit and f or j channel and fascia.
Cut your soffit.
If the soffit on your house wraps around a corner you will need to.
Lift the fascia trim into position over the fascia board.
Hook the curled edge along the bottom of the fascia trim into the channel of the f channel and tuck the top edge of the fascia trim into.
Measure the area to be covered by the fascia.
To install the fascia.
Understand how to deal with wrap around soffit.
Set your j channel along the wall and nail the long side of the channel up to the underside of the soffit.
Cut the fascia to size if necessary.
Punch a hole every 6 to 12 inches 15 2 to 30 5 centimeters along the top surface of the fascia using a snaplock punch.
Siding the soffit and fascia area 1.
If you have an older house chances are these.