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N1101.3 (R101.4.3) Additions, alterations, renovations or repairs.

steveray

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West of the river CT
N1101.3 (R101.4.3) Additions, alterations, renovations or repairs.
Additions, alterations, renovations or repairs to an existing building, building system or portion thereof shall conform to the provisions of this code as they relate to new construction without requiring the unaltered portion(s) of the existing building or building system to comply with this code. Additions, alterations, renovations or repairs shall not create an unsafe or hazardous condition or overload existing building systems. An addition shall be deemed to comply with this code if the addition alone complies or if the existing building and addition comply with this code as a single building.

Exception:
The following need not comply provided the energy use of the building is not increased:

5. Reroofing for roofs where neither the sheathing nor the insulation is exposed. Roofs without insulation in the cavity and where the sheathing or insulation is exposed during reroofing shall be insulated either above or below the sheathing.

Does anyone else read this as: You strip your asphalt shingled roof and you insulate the attic (or roof) to current code?
 
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In some areas of the country, only Commercial roofs have insulation
installed between the purlins [ i.e. - cavities ]........Residential [ typically ]
has the thermal insulation installed between the ceiling joists.

But, "Yes, ...that is the way I read it also !"



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I'll agree that it reads that way. I'll also agree that I'm not enforcing it.

If they're doing any deck repair, and therefore already have it open, I'll make them blow in enough to get to an R49. Otherwise, no.
 
Thanks all!....I just have some issues here where we would be held criminally negligent for not enforcing it....This is going to suck....
 
More often than not, by the time an owner gets around to re-roofing the decking is water soaked and/or deteriorated. At that point an un-insulated attic becomes apparent and the insulation will need to be added.
Not enforcing a code provision you don't care for or don't agree with would be dereliction of duty, but who am I to judge... :(
 
(23) The building official may waive minor building code violations that do not constitute an imminent threat to property or to the health, safety, or welfare of any person.

I think I am covered if the insulation upgrade is not done during a re-roof
 
Nor does NYS... Waivers and variances go through the State here, and NYS Energy Law is separate legislation from the Building Code Act. NYS takes Energy Code compliance seriously.
 
my first guess would have been that the roof when exposed, needs to be insulated with the r-3/inch value in the existing cavity, and not necessarily brought up to current insulation requirements. I will look at the commentary when i am at the office tomorrow.
 
Commentary;

"Exception 5 applies to roofs that are part of the building envelope and typically would have below-deck or above-deck insulation. The second sentence of Exception 5 permits the code-required insulation to be above or below the deck. For a typical single-family home (with nonconditioned space), the ceiling is the building thermal envelop and the roof is not; therefore, Exception 5 would not apply. However, if during reroofing the existing ceiling cavities are exposed, then Exception 3 would apply."

"Exception 3 is important for a couple of the limitations that it contains. First of all, the provision only applies when the ceiling, wall or floor cavity is "exposed during construction." If the cavity is not opened up, then there is no requirement to do anything. If the cavity is exposed, the requirement will only be to "fill" it with insulation. Therefore, the level of insulation is not required to comply with the building thermal envelope requirements, but is intead only required to be "filled" with any type of insulation and not to any specific R-value."
 
Thanks Francis!....I think 3 and 5 conflict a bit as 5 specifically references "sheathing or insulation" exposed and upgrading....So now this will apply to cathedrals only? Even worse to retro, or do we ignore it as we would "assume" the cavity is full? And then one could argue (in this part of the world) that almost any roof is part of the envelope (in part) at least near the bearing walls as the R30-38 usually fills the area near the bearing of the rafters for a couple feet.....
 
Michigan rewrote this to read:
5. Reroofing where the roof is part of the thermal envelope, and where neither the roof
sheathing nor the roof insulation is exposed.
6. Reroofing where the roof is not part of the thermal envelope.

Unintended consequence of adding insulation is that the snow won't melt off causing excess loading of the structural components not designed to carry the additional weight which could lead to roof collapse.
 
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