Where are you located? Does the home have good attic ventilation, both intake and exhaust?
I personally do not feel the insulation would be cost effective but, if your ventilation was limited (which sound like it is not), the insulation could help with avoiding condensation. Make sure that the metal roof manufacturer approves whatever your final assembly is.
Depends on what is costs and as Todd was getting at, in a vented assembly it is far less important.
If this roof were a non-vented assembly, above deck insulation and ventilation is absolutely critical.
Does adding the insulation (especially with a radiant barrier and air space) hurt you here...definitely not. Is it worth they investment? That is more the question.
is it a cost effective benefit of installing insulation (1/2 in iso board rmax) between titanium udl 50 and 1x4 wood perlins when installing r panel metal roof over asphalt shingles
new orleans, exhaust should be fine, install in cor a vent 400 under drip edge and cutting 1x2 wide by 3/8 deep groves on bottom of perlins, also installing lomanco heavy duty alum. ridgevent, soffiet vents are continuous and have 20 more percent air flow than ridge. top of r panel is also vented to ridge vent
which place do you want to process this installation?
