Roof Valley With Two Different Pitches

Valleys are typically found where gable dormer roofs meet the main roof or when a house has angled wings or additions where two roof sections in different planes meet.

Roof valley with two different pitches. For example on a roof where the two sloping roof planes have different pitches the closed cut valleys can make the entire roof appear as if it s draping over the surface. The valley area of a roof the straight lines formed when two different planes of the roof meet is a critical area that handles a tremendous amount of water run off. Using a pitch measuring tool that i d made we also determined that the exact pitch of the shed roof was 3 1 2 in 12. Joining these two roofs poses two main challenges.

This allows water to flow off the upper panels out over the trim onto the lower panels and exits the roof at the eaves. Learn more about off angle roof framing. As another benefit to the roofing professional open valleys are sometimes used to easily bridge the gap between roof faces of vastly different pitches. One is getting the two differently pitched planes to meet at the hip or valley rafter.

An open valley on the other hand doesn t look as good on valleys where the planes have different slopes. We re going to install it over top of the panels that have already been installed on the lower slope. Blind valleys simplify framing to keep the porch roof framing as simple as possible we installed a structural ridge supported by posts at each end with the common rafters landing on top of the ridge. First we should establish the pitch of both roof planes.

Open metal valleys also lack the aesthetic appeal of closed valleys. The other is to get the fascias to line up. Determining the slope and skew angles related to hip and valley beams can be a challenge made even more difficult when the roof slopes on each side if the hip or valley are different. This slope and skew calculator makes it easy by performing all of the necessary trigonometry for each hanger condition in the roof.

A sketchup model helps clarify how various rafters and framing components are assembled in an off angle hip and valley configuration. The piece that allows us to join the two different slopes is the pitch transition trim.