rafter ridge board

[s14598a]

I am trying to find out what would be the best practice to fix a problem with a Ridge board that is a inch higher than the rafters.  Should I add a 2x4 to the bottom of the ridge board to cover the rafters or install a rafter tie  right below the ridge board.  Any help! Thanks Dave

[MountainDon]

Hi Dave,   

Yes, by all force a 2x4 into that space to provide a surface for the rafter tips to be fully supported. It is possible that a split could form in the rafter at that point where the rafter angle face is not supported.

BTW, what you called rafter ties just below the ridge board would be called collar ties. You should have them anyhow. Their purpose is to prevent the rafter tips and the roof sheathing from separating under conditions of high winds. Collar ties must be placed in the upper third of the rafter span. They should be no more than 48" apart and can be 1x4, or larger. Three 10D nails at each end. An alternative is a steel strap over the top, spacing the same, same nails.

A rafter tie, OTOH must be placed in the lower third of the rafter span. They are to restrain the spread of the side walls. Their nailing schedule varies with span and whether or not they are at wall tops or higher in the lower third.

See this page   http://publicecodes.cyberregs.com/icod/irc/2012/icod_irc_2012_8_par027.htm
and scroll down to section TABLE R802.5.1(9)  right near the bottom.

[s14598a]

Thank-You MountainDon for the reply and information. It was very helpful!
                                                                                                Dave