Use underlayment to compensate for low pitch???

[PostFrameSE]

Is it possible to design a house addition with a cedar-shake-roofed that is below the code-prescribed 4/12 roof pitch? I'm needing to get down to a 2.25/12 pitch for a small 16' x 16' section of roof. Is using Ice-and-water shield or similar products under the entire section a viable alternative? I'm planning on specifying Cedar Breather so that the shakes are not right down on the roof deck.

Thanks.

 

[MiketheEngineer]

Check w/ the mfg. If you go below their pitch or the code recommendations - you own the roof.

 

[diarmud]

The state building code probably has a specific requirement for anything under 4/12. There are products designed for this.

Good luck,
Dermott