Step-by-Step on How to Do a Cornice Fascia
While it may have a bit of a strange name, cornice is just the name given to the assembly used to treat the rafter ends, or tails, that protrude from the side of a building. Cornice consists of two main parts, the soffit which is the underside of the joists or rafter tails, and the fascia which covers the actual end of the rafter tails. Does this Spark an idea?
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Things You'll Need
- Table or circular saw
- Miter saw
- Hammer
- Nails
- 1/4-inch plywood
- 3/4-inch thick boards
Instructions
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Determine the width of the soffit by measuring from the face of the house to the edge of the rafter tails and add 1/4 inch.
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Cut the soffit to the desired width using a table saw or circular saw. Make the soffit out of 1/4-inch plywood.
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Nail the soffit to the underside of the rafter tails. The soffit should butt the face of the house and extend past the end of the rafters by 1/4 inch and it should break on the middle of a rafter tail, so cutting may be required.
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4
Choose the width of the fascia by measuring from the top of the roof deck to the bottom of the soffit and add 1/2 inch to the measurement.
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5
Rip the fascia to the desired width out of standard 3/4-inch thick boards.
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Create a 5/16-inch wide by 5/16-inch deep dado in the back side of the fascia that starts 1/2 inch from the bottom edge. This dado will receive the soffit that extends past the rafter ends. Make the dado by setting the table saw blade 5/16 inch above the saw table and set the fence 1/2 inch from the blade and make one pass. Measure the width of the cut and subtract it from 5/16 inch. Move the fence away from the blade that distance and make a second pass. The dado should now be 5/16 inch wide and deep.
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Install the fascia by starting at one end of the roof and work your way around. Place the dado over the soffit that extends past the rafter edge and nail the fascia to the rafters. All joints should cut on a 45 degree bevel and should be glued and nailed together, using an exterior glue and galvanized nails.
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Cover the soffit-wall joint with a decorative moulding such as bed moulding, and nail it in place.
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Nail the shingle, also known as rake, moulding to the face of the fascia. The top of the moulding should be flush with the top of the fascia. Shingle moulding typically is placed only along the gable ends as it would interfere with gutter installation along the bottom of the roof. Cut the shingle moulding flush with the bottom end of the gable fascia.
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Tips & Warnings
Pressure treated lumber isn't needed as the water contact for the cornice is minimal and it will usually be protected by paint. Also, pressure treated lumber is usually full of knots and may shrink dramatically as the lumber dries out. Fir makes for a good fascia choice as it is straight-grained with few knots. For maximum durability, use a cement-based product such as Hardie-plank or a recycled plastic product such as Azek trim boards. Stainless steel nails, while costly, won't rust over time like galvanized nails may. Precut soffit panels are available at most home improvement centers and may be a time saving option.
