How Much Slope Does Metal Roof Need Over A Deck

The minimum slope for lapped non soldered seam metal roofs without applied lap sealant shall be three units vertical in 12 units horizontal 25 percent slope.

How much slope does metal roof need over a deck.

I ve built many of those patio covers over the years it rains a lot in oregon and they ve been fine. If the span under your deck is 12 ft for example the purlin at the outer end of the deck should be 3 in. Minimum metal roof slope depends on the roof profile building design climate and site location. Minimum slope over deck.

Most metal roofs will have minimum pitches of three in twelve but this might sometimes go down depending on whether there are special installation procedures issued by the manufacturer regarding that particular roofing material. Low slope roofs are not totally flat their roof slope generally ranges from 1 4 12 to 3 12. The pitch is measured in inches of vertical rise per foot of horizontal run and the 5v crimp profile shown above requires a minimum slope of three in twelve or 3 12 3 inches vertically per 12 inches horizontally. Standing seam metal roofs with mechanical lock systems to ward off leaks can be successfully and attractively installed on roofs with at least a slope of 1 in 12.

The minimum pitch for a standing seam metal roof is 1 4 or 3 inches rise to 12 inches run. The minimum pitch for roll roofing is 2 12 or 2 inches rise to 12 inches run. To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope. Profile in the context of metal roofing means the shape that the sheet of metal is bent into to form the panels.

According to the 2012 international building code 1507 4 2 deck slope minimum slopes for roof panels need to comply with the following. Low slope metal roofs have simple geometries and are easier and less expensive to install that medium to steep slope roofs. Metal should never be set up on a completely flat roof since they were not designed to handle pooling water which will lead to premature rusting and deterioration. To provide drainage the panels should slope toward the outside edge of the deck about 1 4 in.

I will be attaching it to the house and the roof is 12 x20 with the 12 being the direction the water will be flowing. Low slope metal roofs require less material which reduces the overall load on the building s structure. Minimum slope for metal roof realistically any more than 1 4 per foot would okay at all but the most windy times. Lower than the purlin along the house 12 x 1 4 3.

Since it s just over a deck if it had at least that much i probably wouldn t comment. A roof with a 6 rise for every 12 run has a 6. First mark all the purlin locations on the deck joists. Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot.