Step 1: Remove the Siding

Remove the siding on the house in the area you will be working -- from the top down to right above the door. You need to use scaffolding because it is the safest way to work. Remove the nails and then pry each piece of siding out all the way to below where you want the portico to tie in.

Expert Tip: It's a good idea to mark the back sides of the siding with a grease pencil as you take them off so you can replace them in their exact spot later.

Step 2: Pry Out the Sheathing

Identify where the top plate is (usually the sheathing will break right at the top plate). Cut out the section of sheathing around where the base of the roof will meet the top plate. Use a circular saw to cut through the sheathing; then pry it out with a hammer or a wonderbar. Do this on both sides.

Step 3: Attach the Joist Hangers

Measure up eight feet from the bottom, and attach the 2x6 joist hangers to the studs using joist hanger nails. Then slide the 2x6's into the joist hangers. This creates a place to tie-in to the house.

Step 4: Mark for the Column Bases

Figure out the exact length of the portico frame. Mark where the column bases will go (about 1/1-2" from the edge of the step).

Step 5: Find the Center of Each Square

Identify the center of each square. Measure from the tie-in beam out. Use a chalk line as a plumb bob to find the measurement.

Step 6: Nail the Pieces at an Angle

To build the three-sided framework for the roof to sit on, cut four pieces of 2x6 -- two to the measurement you just took and two 1-1/2" shorter so you can stagger the joints of the frame. Nail them together at an angle for a better hold using 16-penny nails.

Step 7: Determine the Length of the Short Board

Determine the length of the short board by measuring the distance between the posts. Cut one 2x6 to that length and cut another 3" longer for the staggered joint.

Step 8: Lay Out the Frame

Add some construction adhesive to the ends and fit the frame together (figure D). Use a nail gun and 16-penny nails. Add the long board to the front rim and attach it.

Step 9: Add a Temporary Back Board

Put up a temporary back board to help keep the frame steady. This board will be removed later.

Step 10: Place the Box

Set the box into place. With help, set the two return boards onto the top plate and fasten the other ends to temporary posts. They will be replaced later with the columns.

Step 11: Place Joist Hangers

Put joist hangers on 2x6 braces on joist hangers using measurements from front rim.

Step 12: Attach Two Temporary Posts

Build two temporary posts from 2x6's and set the frame on these posts and nail it in. This will hold the frame in place while you work, and then you'll set the return boards into their joist hangers.

Step 13: Level the Box

Level the box so that the end is totally level or slightly higher than the house side so that you can easily replace the temporary posts with real ones later.

Step 14: Attach the Return Boards

Attach the return boards with hanger nails. Put both temporary posts into place and remove the temporary brace.

Step 15: Replace the Insulation and Sheathing

Once the box is in place, replace the insulation and sheathing. Notch to allow for the 2x6's and nail it back on.