Step 1: Attach the Plywood

Attach 4x8 plywood with a nail gun with 8-penny nails about every 6". Close the peak with plywood cut to whatever size you need.

Step 2: Attach the Shadow Board

Attach the shadow board where the sheathing meets the fascia, and cut at an angle on the front to fit it into place.

Step 3: Attach the Ice and Water Shield

To shingle the roof, put up the drip edge with roofing nails. Attach the ice and water shield. It is self-sticking, but use a hammer tacker as well.

Note: A roofing gun can be rented for approximately $25 a day.

Step 4: Begin to Shingle

Start shingles on the bottom and double up the first row of shingles in order to totally cover the surface.

Expert Tip: Use stepflashing as roofing to prevent water from running between the portico and house.

Step 5: Attach the Beadboard

Attach the beadboard on the inside of the portico with finishing nails. You need to keep cutting pieces of beadboard and fitting them into place.

Step 6: Wrap the Box

Wrap the box with 1x pre-primed pine. Not only is it visually pleasing, it will add weight to the structure and cover the edges where the beadboard ends.

Step 7: Cut the Columns

It is time to install the columns. Move the temporary bracing. Cut the columns to size, set them in place and plumb. Make sure the load is centered right over the column shaft and evenly distributed.

Note: You can choose square or round columns and there are a number of different options for the caps.

Expert Tip: When installing columns, it's important that you anchor the columns to the subfloor that you're working with, and in this particular case the subflooring was concrete. In this case use two L-brackets and pre-drill holes both into the subflooring and columns.

Step 8: Anchor the Columns

Anchor the columns to the surface. Mark and drill holes in the floor and the column shaft of the corner irons. Attach the corner irons to the column shaft using deck screws, concrete anchors or toggle bolts.

Step 9: Apply the Construction Adhesive

Put construction adhesive on the bottom of the column base and slide it into place.

Note: Use high quality, exterior-grade, non-acetone based construction adhesive.

Step 10: Secure the Caps

After the two bases are set, set the portico down on top of the columns. You'll need three people for this part. Apply the adhesive and slide the caps into place. Secure them with a finish nailer.

Step 11: Reattach the Siding

Reattach the siding by trimming pieces of "J" molding to fit around the portico where the siding meets. Use tin snips to trim the pieces, then nail them on with roofing nails.

Step 12: Fit the Pieces Around the Portico

Trim the siding pieces to fit around the portico and measure using sliding "T" bevel to match the angles. The "J" molding will cover the edges of the siding.