Roof Ridge Different Heights

The top of the ridge beam m y.

Roof ridge different heights.

I am trying to create the roof for a complex house with 10 and 12 walls. The only way to eliminate that is to block off each level of attic area. Rafters are nailed to the ridge board and run down to overhang the exterior wall. To scribe the roof angle on the ridge a length of stock is leveled over from the common rafters and a 2 by scrap is set against the sleepers.

Unless its separated from the main attic space. Another by product of this roof configuration is varying soffit heights and widths which require further design decisions. Because the level cut on the jacks would be so long we added 2x4 sleepers inside the 2x8s for a more complete bearing surface. My roof guy said ridge vents shouldn t be installed at different heights.

I cannot seem to make this work. I have attached pictures of an example of one of the sections i am trying to create the roof for. In a typical saltbox house one side of the roof covers the top floor of the house while the other side slopes all the way down to the ground floor. For example along the long peak and then on the gables that blend into the roof at a lower level than the highest long peak.

This roof is used in asymmetrical houses where the upper floor doesn t completely overlay the lower. Carpenters measure roof pitch as inches of rise per 12 inches of run. Air is like water. 3 difference is our rule of thumb.

The house has multiple rooms with differing wall heights. The roof with the lower eave height would require a roof slope pitch greater that the roof with the higher eave height. Roof pitch calculator results explained. A 1 in 12 roof pitch roof rises 1 inch for every 12 inches of run.

Since the beam height is 1 taller then the 8 wall height that gives you a triangle with a 7 12 pitch with a 1 rise and a run of 20 9 16 and a rafter length of 23 13 16. The saltbox roof has two sides of different lengths which slope outwards from a central ridge. To determine the finished height of the ridge beam add the rise m and the y height. The pitch of a roof determines the height of the ridge board that runs the length of the house.

To determine the y height measure from the bird s mouth up the calculated slope x in 12 to the top of the rafter. Therefore that will move your ridge from the center of the 40 3 1 2 span. To keep the ridge line centered on the structure and have 2 eaves at different heights with identical overhangs you would have to have 2 different roof slopes. The reason being is the the higher long peak ridge vent end up drawing air through the lower smaller ridge vents on the peak.

Even at a 3 difference in height the ends of the lower ridge vent will become intakes for the higher vents.