Typical decks are designed to support 55 psf lbs per square foot.
Pitch for under deck roof.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
As a result most decks have inadequate footings to support a new porch roof.
Then stretch a string between them.
Among the newest is the raintight system introduced at deck expo 2014.
Lower than the purlin along the house 12 x 1 4 3.
Liquid applied roofing requires a minimum roof pitch of 1 4 12 or greater.
That is to say the roof pitch expressed as a ratio tells you how many inches the roof rises for every 12 inches of depth.
The footings for porch decks must be larger than deck footings.
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.
This is for metal roofs that have a sealant between their lapped seams.
If you consider it as similar to a roof than according to code.
Consider including an ice and water barrier too.
Many porches use 22 diameter corner and intermediate footings.
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.
Modified bitumen roofing requires a minimum roof pitch of 1 4 12 or greater.
Thermoset and thermoplastic single ply 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.
So let s say a roof rises 6 inches for every 12 inches in depth towards the peak.
Sprayed polyurethane foam roofing requires a minimum roof pitch of 1 4 12 or greater.
If the span under your deck is 12 ft for example the purlin at the outer end of the deck should be 3 in.
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.
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.
Minimum slope is 1 4 inch vertical in 12 units 2 slope and ideally 1 2 vertical in 12 units 4 slope.
The primary reason roof pitch exists in the first place is to redirect water.
The slope or pitch of the under panels can be at any degree that will shed the water.
The roof pitch would be described as a 6 12 pitch.
Convert the space under a second story deck into a dry spacious patio by installing this simple under deck ceiling and gutter system.
The most common styles are gable hip and shed.
However you can only use this pitch with built up roofing or specialized synthetic roofing.
