Polyiso on exterior wall - best practice

[flightcrazed]

Hello,

Anyone with experience putting rigid Polyiso board over sheathing and covering with Metal siding?  Curious if this is a best practice (using the polyiso as WRB) or if better to put a barrier between it and the wood sheathing and/or the metal.

 

Thanks!

Shawn

[Gawdzira]

From the Hammer and Hand best practices

 

https://hammerandhand.com/best-practices/manual/5-envelopes/5-4-exterior-continuous-insulation-ci-at-walls/

[SHCanada2]

Polyiso has different advice. From the link above

 

Foil-Faced Polyisocyanurate (Polyiso)

• Exterior surface may be used as a WRB, with manufacturer approval.
• Install tape at seams per manufacturer specification.

1. Must use J-Roller on tape with good detailing to eliminate ‘Fish-Mouthing.’