Proper Flat Roof Installation

Model building codes and good roofing practice have established a minimum slope for roofs at 1 4 12 running inches.

Proper flat roof installation. Codes also recognize the challenges to meet this criterion in reroofing of existing buildings. Work up from the initial row starting at the lower corner in a diagonal pattern staggering the shingles to prevent gaps. To keep water from pooling at these inside corners tom rips 2x4s lengthwise on a 45 degree bevel with a table saw. If you come across any large nails that are sticking out either remove them and put them in your debris container or.

If your home already has a built up roof then replacing it with another built up roof is a good idea. 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. Trusses or rafters should be shimmed as necessary to provide a level nailing surface. Lay the starter row of metal shingles at the drip edge and affix to the roof with metal roofing nails.

Then remove the rest of the roof including all the shingles. 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. On two sides the roof abuts a parapet a short wall common around flat roofs as well as a wall for the third floor. If you need to reposition your gutters do so at this.

The basic construction of a flat roof starts with roofing timber that is laid across two upright items usually two walls. Built up flat roofs are very sturdy because they have so many layers. Remove any nails sticking out and reposition any metal gutters so that water flows properly off the roof. However those layers make the roof very heavy.

This can be done with a straight piece of lumber 6 feet to 10 feet long or a long carpenter s level. 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. Here the rubber roof will need to run up the walls and glue to the sheathing.

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. Most metal shingles will be attached to the roof using metal shingle. All roof areas shall be designed and installed to drain without holding water on the roof surface. This will give additional stability to the roof structure.

Use a tin snips to cut the drip edge to size. Start at the highest point and the furthest point from the trash container and take off all the old shingles flashing.