If the span under your deck is 12 ft for example the purlin at the outer end of the deck should be 3 in.
How much of drop should patio roof with plastic.
Apply front and back panels similarly to side walls.
The slope should be at least 1 inch for each 8 feet of patio.
Some additional considerations for this project.
Plastic patio pergola awning covers polygal roof panels clear patio covers for pergolas multiwall polycarbonate sheets often referred to by the brand name of polygal are a structured sheet product available in double and triple layered configurations and manufactured in various colors and degrees of transparency.
However an ideal roof drop per foot should be at least one eighth to one quarter of an inch per foot.
Roof pitch in layman s language simply refers to the steepness of the roof.
Some building codes start at one quarter of an inch per foot or two percent.
Anything less than one eighth of an inch may pool on the roof.
A 16 foot patio will need 2 inches of slope.
The pitch of a roof is arrived at by dividing the vertical rise and its horizontal span or what people in the roofing industry would refer to as the slope.
To provide drainage the panels should slope toward the outside edge of the deck about 1 4 in.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
For example a 12 foot patio will need 1 inches of slope.
I know the standard is to have 1 4 drop per foot but have you ever been on a patio with a steeper grade and it still get relatively flat.
One contractor said 1 1 4 1 1 2 inch we wouldn t notice but i find that really hard to believe and gave me question as to his integrity.
Cut to fit pitch of roof and around vent.
Fasten aluminum ridge roll flashing to each panel as you proceed.
Nail trim limber to all corners and to front and back where panels meet roof.
However you can only use this pitch with built up roofing or specialized synthetic roofing.
Determine the amount of slope needed for the size of the paver patio.
Lower than the purlin along the house 12 x 1 4 3.
Anything with a slope of some kind will cause water to run off the roof.