Roof Ridge Different Heights

To determine the finished height of the ridge beam add the rise m and the y height.

Roof ridge different heights.

The most common parameter is to maintain an equal ridge height over building sections with differing spans. 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. 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. 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.

I cannot seem to make this work. 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. To maintain a consistant ridge height in these situations the roof pitch must be adjusted. The only way to eliminate that is to block off each level of attic area.

The top of the ridge beam m y. Roof pitch calculator results explained. This roof is used in asymmetrical houses where the upper floor doesn t completely overlay the lower. Even at a 3 difference in height the ends of the lower ridge vent will become intakes for the higher vents.

To determine the y height measure from the bird s mouth up the calculated slope x in 12 to the top of the rafter. In certain sections of the house the roof overlaps the high and low sections. 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. Rafters are nailed to the ridge board and run down to overhang the exterior wall.

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. Air is like water. The roof with the lower eave height would require a roof slope pitch greater that the roof with the higher eave height.

The saltbox roof has two sides of different lengths which slope outwards from a central ridge. Therefore that will move your ridge from the center of the 40 3 1 2 span. Carpenters measure roof pitch as inches of rise per 12 inches of run. A 1 in 12 roof pitch roof rises 1 inch for every 12 inches of run.

I have attached pictures of an example of one of the sections i am trying to create the roof for. The house has multiple rooms with differing wall heights. 3 difference is our rule of thumb. The reason being is the the higher long peak ridge vent end up drawing air through the lower smaller ridge vents on the peak.

I am trying to create the roof for a complex house with 10 and 12 walls.