Proper Flat Roof Installation

Start at the highest point and the furthest point from the trash container and take off all the old shingles flashing.

Proper flat roof installation.

Start at the bottom side of the gable and overlap the sections of drip edge a few inches as you work your way up the roof see figure a. Built up flat roofs are very sturdy because they have so many layers. Here the rubber roof will need to run up the walls and glue to the sheathing. On two sides the roof abuts a parapet a short wall common around flat roofs as well as a wall for the third floor.

However if you have a different type of flat roof then talk with a licensed roof contractor because you may need to add extra roof support. This will give additional stability to the roof structure. First focus on removing the oldest shingles that are sticking out as well as any flashing or vents. If you come across any large nails that are sticking out either remove them and put them in your debris container or.

Underneath the basics flat roofs are usually constructed with a ceiling nailed to joists which support a deck usually wood in residential construction a vapor barrier insulation and a roof board. Model building codes and good roofing practice have established a minimum slope for roofs at 1 4 12 running inches. This can be done with a straight piece of lumber 6 feet to 10 feet long or a long carpenter s level. Use a tin snips to cut the drip edge to size.

Trusses or rafters should be shimmed as necessary to provide a level nailing surface. All roof areas shall be designed and installed to drain without holding water on the roof surface. Work up from the initial row starting at the lower corner in a diagonal pattern staggering the shingles to prevent gaps. The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls.

If you need to reposition your gutters do so at this. From there the flat roof system you choose will determine the materials you apply. Lay the starter row of metal shingles at the drip edge and affix to the roof with metal roofing nails. Install the drip edge on the gable ends of the roof after you finish installing your underlayment.

If the top chords of trusses or rafters are warped or bowed install blocking to straighten. Remove any nails sticking out and reposition any metal gutters so that water flows properly off the roof. For additional stability you can also use steel joists that are built into one or both of the walls. To keep water from pooling at these inside corners tom rips 2x4s lengthwise on a 45 degree bevel with a table saw.

Codes also recognize the challenges to meet this criterion in reroofing of existing buildings. However those layers make the roof very heavy.