Hi all,
I've read as much as I can about this and no obvious absolute answer. Looking for opinions.
Situation: Full plans building regs application has been accepted (done by me from BuildingRegs4Plans) by LABC. Lean-to extension with low pitch (15deg) double hipped roof. Vaulted ceiling though I may add a small flat ceiling at highest point. Basically two walls to "fill in" a corner of the house.
Internal dimensions 3.23m x 5.26m. Timber sizing for common rafters based on TRADA span tables (significantly over spec due to insulation depth). Doubled up hips of one "size" bigger than commons.
Building control have accepted the spec of the roof without requesting SE calcs (its only a small roof) but I dont want a last minute "prove its ok" type issue.
Roof load is 0.75kN dead and 1kN imposed (South Yorkshire - snow). Interlocking clay tiles on battens.
Im intending 47x175mm C24 @400mm centres for the commons (max span 3.35m) and doubled up 47x200 C24 for the hips. I've attached a roof framing plan. It is assymetric due to centering on existing gable (bonkers house).
Does this sound reasonable or should I increase to doubled up 47x225 for the hips? (225 will likely be visible internally when boarded).
Cheers
Joe
I've read as much as I can about this and no obvious absolute answer. Looking for opinions.
Situation: Full plans building regs application has been accepted (done by me from BuildingRegs4Plans) by LABC. Lean-to extension with low pitch (15deg) double hipped roof. Vaulted ceiling though I may add a small flat ceiling at highest point. Basically two walls to "fill in" a corner of the house.
Internal dimensions 3.23m x 5.26m. Timber sizing for common rafters based on TRADA span tables (significantly over spec due to insulation depth). Doubled up hips of one "size" bigger than commons.
Building control have accepted the spec of the roof without requesting SE calcs (its only a small roof) but I dont want a last minute "prove its ok" type issue.
Roof load is 0.75kN dead and 1kN imposed (South Yorkshire - snow). Interlocking clay tiles on battens.
Im intending 47x175mm C24 @400mm centres for the commons (max span 3.35m) and doubled up 47x200 C24 for the hips. I've attached a roof framing plan. It is assymetric due to centering on existing gable (bonkers house).
Does this sound reasonable or should I increase to doubled up 47x225 for the hips? (225 will likely be visible internally when boarded).
Cheers
Joe
