The primary reason roof pitch exists in the first place is to redirect water.
Pitch for under deck roof.
Among the newest is the raintight system introduced at deck expo 2014.
Modified bitumen roofing requires a minimum roof pitch of 1 4 12 or greater.
Porch decks require 25 additional psf for roof loads for a total of 80 psf.
The footings for porch decks must be larger than deck footings.
Liquid applied roofing requires a minimum roof pitch of 1 4 12 or greater.
Step 2 install a wood support structure for your panels screwing a row of 2 by 4s running parallel to your wall every 2 feet along the underside of your deck.
Convert the space under a second story deck into a dry spacious patio by installing this simple under deck ceiling and gutter system.
Thermoset and thermoplastic single ply roofing requires a minimum roof pitch of 1 4 12 or greater.
Many porches use 22 diameter corner and intermediate footings.
The most common styles are gable hip and shed.
So let s say a roof rises 6 inches for every 12 inches in depth towards the peak.
Minimum slope is 1 4 inch vertical in 12 units 2 slope and ideally 1 2 vertical in 12 units 4 slope.
For a house roof the recommended minimum slope is 2 5 vertical inches for every horizontal foot but a nearly flat roof is fine for under deck installations.
Consider including an ice and water barrier too.
Then stretch a string between them.
The slope or pitch of the under panels can be at any degree that will shed the water.
This is for metal roofs that have a sealant between their lapped seams.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
If you choose to add a roof to an existing deck you may need to add additional supports so it can hold the weight of the roof.
A number of recently introduced under deck ceiling systems use corrugated aluminum or plastic panels designed to catch water that drains through decking and channel it away from the area below.
As a result most decks have inadequate footings to support a new porch roof.
Typical decks are designed to support 55 psf lbs per square foot.
Adding a roof to your deck is best done as the deck is being built.
The roof pitch would be described as a 6 12 pitch.
If the span under your deck is 12 ft for example the purlin at the outer end of the deck should be 3 in.
First mark all the purlin locations on the deck joists.
However you can only use this pitch with built up roofing or specialized synthetic roofing.
If you consider it as similar to a roof than according to code.
Sprayed polyurethane foam roofing requires a minimum roof pitch of 1 4 12 or greater.
