With the a major section of the deck completed and having the railed section finished, it’s now on to the expansion of the screened in porch. I wanted to do something a bit different with this part of the project. I had first planned to just extend the roof line of the existing porch with a “roof” made of screen rather than the standard shingles most often used in Midwestern porch construction, But as I’ve written in the past, sometimes ideas just seem to present themselves. And as a result of having dinner under a restaurant’s pergola one evening, I decided that a pergola roof would look much nicer, be easier to build even being a bit more expensive.
We started with the floor joists. In the picture below note that the joists are doubled up and have upside down joist hangers attaching them to the ledger board (on the left). Due to the fact that my support beam in this section was just 44 inches from the ledger board, standard building code would have limited my cantilever past the support beam to just 11 inches. So I retained a certified professional engineer to design the construction method in this area. The upside down hangers are designed to prevent up lift forces from the longer cantilever.
Before the center porch roof supports on the outside wall can be removed, the roof structure would need to be re-enforced. I did this by “simply” installing additional header supports. Added were two 2×6′s above the existing ones and an additional 2×12 outboard of the existing headers. In the picture below, you can see the installed 2×12 below the 2×8 cedar board.
With the decking installed and roof re-enforced, it was time to start the porch framing expansion. I am using the same cedar posts that were used in the existing porch. I planned for only the corner posts to be attached to the main deck construction. I did this by cutting a hole in the deck to match the size of a section cut from the bottom of the post. Once inserted into this pocket the bottom of the post would be screwed to the main deck structure.
Each of the two corners were installed in this manner and then the outside posts were tied back to the porch with horizontal beams. The top beams were attached to the vertical posts using a simple but yet strong lap joint. They were screwed together using 6 inch construction screws using impact driver drill.
Once the outside posts and top beams were installed, I simply filled in the other vertical posts screwing them to the top beam and bottom deck. The horizontal members are 2×4. All of this section is constructed from rough cedar which will be later stained. The next step was to install the pergola roofing members with pre cut ends and installed to the top beams with 3 inch deck screws.
At this point I was ready to install the screens using the tried and true method of staples to be later covered by 1×4 batten boards.
inside view of the bigger porch space.
View from the outside of the finished expansion (other than the planned wrapping of the lower section of the deck in matching cedar)
In the end, the porch expansion turned out better than I expected. With the completely different roof lines, I decided rather than paint the cedar gray to match the existing porch, I would stain it to give this new area its own character and style.