Roof Ridge Board Thickness

For 2 x 6 rafters use a 2 x 8 ridge board and so on.

Roof ridge board thickness.

Roof pitch between 15 and 22 5 degrees with rafter spacing strength class c16 size of rafters in mm 400mm 450mm 600mm. Ridge boards can only be used in roofs with slopes from 3 in 12 up to 12 in 12. Ridge boards shall be at least 1 inch nominal thickness and not less in depth than the cut end of the rafter irc section r802 3. This sizing guide for roof rafters will help determine what you need for your small project.

If your goal is to only calculate the roof height do not enter any numbers in wall height field and only use building width and roof pitch fields. The ridge board s length will be the outside measurement of the building plus the length of the overhang at both ends. Typically 15 32 inch or thicker panels are required in high wind areas. For 2 x 4 rafters use a 2 x 6 ridge board.

Use panels rated as exposure 1 or better. You may splice two boards together to achieve this length if necessary using a 14 and 1 2 inch block of the same material. There are several variables to consider when determining the proper rafter size.