"George" wrote in message
...
We have a roof problem that could most easily be solved by doing
somethign that would lower the pitch from 4:12 to 3:12. I keep hearing
that 4:12 is the "minimum" pitch for a shingled roof. But, that's also
what it was in the Stone Age.

I wonder if that rule still applies, if I underlaid the whole thing with
a bituminous membrane (aka "ice and water shield")?

Thanks,
George

4:12 is the minimum for a "standard installation". The IBC code allows
shingles down to a pitch of 2:12 with restrictions.

At 3:12 I would use 30 pound felt well over lapped and reduce the exposure.
The roof may not last quite as long but it should shed water. It may also
affect your warranty. Never seen one of those pay off any way.

Check for local code restrictions before you start. Some local codes are
more restrictive.


Colbyt