Valley Between Two Pitched Roofs

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.

Valley between two pitched roofs.

At the low end of the valley the subfascias of the two roofs are mitered with a block filling in the roof framing. 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. They can only be used when the pitches of the two roofs are identical. The materials they use in valleys are inferior.

Sheathing blocking is added along the valley and the sheathing pieced in for both roof planes. We may not know how to spell but roofing we know best. Valleys on between two slanted roofs causes leaks very often. 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.

Explore framing complexities that result when roofs of two different pitches intersect. Most roofers know how to install shingles but many have no clue how to do a valley. A sketchup model helps clarify how various rafters and framing components are assembled in an off angle hip and valley configuration. A valley gutter is where two main roofs meet or where there is a change in roof direction.

The valley gutter problem areas can be made worse where there are surrounding trees and associated leaves and branches that can block the valley gutters up. This slope and skew calculator makes it easy by performing all of the necessary trigonometry for each hanger condition in the roof. Valley tiles which allow the roof to be continued round corners they are special tiles which are the opposite of a hip tile really. In a hip roof with equal pitches the unit run of a hip or valley rafter is 17 inches for every 12 inches of run in the main roof.

Repairing a valley area on a shingle roof. An open valley often 100mm or 150mm wide with a metal normally lead or sometimes a grp lining. Valley gutters are generally considered to be a problem area. For example in an equal hip roof with an 8 12 pitch the pitch of the hip rafter would be 8 17.