Pitch For Under Deck 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.

Pitch for under deck roof.

The most common styles are gable hip and shed. This is for metal roofs that have a sealant between their lapped seams. If the span under your deck is 12 ft for example the purlin at the outer end of the deck should be 3 in. The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.

The primary reason roof pitch exists in the first place is to redirect water. 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. Adding a roof to your deck is best done as the deck is being built. 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. As a result most decks have inadequate footings to support a new porch roof. 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. If you consider it as similar to a roof than according to code.

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. 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. The footings for porch decks must be larger than deck footings.

Consider including an ice and water barrier too. Thermoset and thermoplastic single ply roofing requires a minimum roof pitch of 1 4 12 or greater. Then stretch a string between them. Liquid applied roofing requires a minimum roof pitch of 1 4 12 or greater.

Many porches use 22 diameter corner and intermediate footings. The slope or pitch of the under panels can be at any degree that will shed the water. Minimum slope is 1 4 inch vertical in 12 units 2 slope and ideally 1 2 vertical in 12 units 4 slope. Typical decks are designed to support 55 psf lbs per square foot.

First mark all the purlin locations on the deck joists. 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. However you can only use this pitch with built up roofing or specialized synthetic roofing.

Install the purlin along the house and the outer purlin.