More in Outdoors
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.
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.
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.
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).
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.
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.
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.
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.
Put up a temporary back board to help keep the frame steady. This board will be removed later.
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.
Put joist hangers on 2x6 braces on joist hangers using measurements from front rim.
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.
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.
Attach the return boards with hanger nails. Put both temporary posts into place and remove the temporary brace.