Flat roof project

This week we finished up the flat roof extension project off our garage. We mostly used milled wood. However, for the posts we used pine trees. These we notched at the top so that a 4x4 could be placed between the posts.

The top edge of the roof was secured to the garage with two 12 foot sill boards.  The sill boards were connected to the garage with 5/8 inch lag bolts.  The bolts were screwed through the siding and into 2x4 studs on the inside wall.  The studs were not uniform.  The bolts went into the wall about every 18 inches.

Rafters were cut with a birds mouth notch on the high end side.  Each rafter notch fit over the sill and were bolted in place to the wall using metal hardware and screws.  The down hill side of the rafters were cut to slide over top the 4x4.  We used 2x4 studs to connect the rafters one to another and stabilize the roof rafters.

On top of the rafters we screwed 1x6 and 1x4 nailing boards.

We finished the structural pieces with metal roofing panels.  Our roofing material came from Eagle Metals.  The folks there set us up with custom cut pieces of 4x12 metal roof panels.

The connection between our roof and the existing roof was made with transition flashing.  The horizontal piece of the transitional flashing slid underneath the last set of existing roof shingles.  Hopefully, that will function to keep our structure nice and dry.  This link has a good summary of the types of flashing needed for roofing construction projects.

Learn from mistakes.  The following were errors made in this project.  First, we did not achieve a sufficient pitch.  It would have been much better to get at least a three inch drop every foot.  We probably have only 2 at best.

Second, it is important to get your roofing set square on the first piece.  Every piece afterward fits into it.  If you are off a small amount, then your roofing ends up slightly off kilter.  Here are some other pictures:

The project is not completed. Still need to add the facia board.