Ventilation of Attic Spaces

[north star]

$ ~ $ ~ $

I have 6 existing buildings that are undergoing a full
renovation, with only a very minor reconfiguring of a
small space for mechanicals ( in 5 of the 6 ).

In all 6 bldgs., the RDP's are showing installing blanket
type thermal insulation over all areas of the underside of
new metal framed roofing and in between the rafters.
The thermal insulation extends over the full length of the
beams down over the vertical walls to include the top
side of the soffit areas........The bottom side of all soffits
indicate metal vented soffits installed [ I hope that
description is clear to you all ].

In all 6 bldgs., the spaces above the ceilings have sloped,
metal roofs & framing, with metal louvers installed [ for
ventilation ]........According to the definition of Attics [ in
the `15 IBC ], I consider these spaces to be Attics.

QUESTION # 1: Are the attic spaces "required" to be
ventilated ?

QUESTION # 2: If you answer Yes to Q # 1, do the
proposed louvers satisfy the requirement of ventilation ?

QUESTION # 3: Are the soffitt areas the only thing being
vented proposed design ?

QUESTION # 4: If the design indicates a "metal vented soffit",
is the air suppose to flow in to the attic space and out the
louvers [ i.e. - a chimney effect ] ?

As always, please support your statements with cited
references............We are using the 2015 I-Codes.

Thanks for your input !

$ ~ $ ~ $

 

[RLGA]

Q #1 - Yes (Section 1203.2)
Q #2 - Maybe. At least 40% but not more than 50% of the required ventilation area can be louvers in the upper portion of the attic (Section 1203.2, Exception 2); the remaining required ventilation area must be at the eaves
Q #3 - I don't really understand the question. Soffits need to be vented, too (Section 1203.2)
Q #4 - If the soffits are part of the roof eaves, then yes, there should be means for air circulation from the eave/soffit vents to the louvers (Section 1203.2, Exception 2)

 

[north star]

& = & = &

Thanks Ron for your quick reply !......You confirmed
what I suspected........The design submitted is not
compliant, plus there is no mention of any type of
rafter cavity baffles, similar to Residential type venting.

I will add this "faulty design" to the Comments I send
back to the RDP.

& = & = &