16D-026 (2) City of Northampton Mail - 116 North Main Street Florence MA 01062 https://mail.goo-le.com/mail/u/0/?ui=2&ik--39211afc3d&view=pt&se...
,r Charles Miller<cmiller @northamptonma.gov>
116 North Main Street Florence MA 01062
1 message
Charles Miller <cmiller @northamptonma.gov> Fri, Feb 27, 2015 at 10:38 AM
To: lcraver@hanover.com
Dear Sir,
In regards to the repairs required at the 116 North Main Street Florence MA I have viewed the existing
conditions exposed after demo was completed. The ceiling structure is substantially under sized by building
code requirements and collar ties are missing from the existing roof structure above. The current attic insulation
level in "Stretch Code Communities" requires R38 and non-stretch code communities R49.
With the a ceiling span of about 16' and with light storage the ceiling joist must be 2x8 minimum. Collar ties are
required at a minimum of every 48" to tie opposing rafters together.
Because 2x8 ceiling joist will be used and a plywood deck placed on top for storage the cavity space is limited
to 7 1/4". To insulate this will require a high density cavity insulation R-30 and that will be a 8 114" batt placed in
a 7 1/4" cavity and rigid polyisocyanurate insulation to make up the difference or a medium density foam within
the cavity. Compressing the 8 1/4" batt into a 7 1/4" space ends up being R26 + 1 1/2 " of polyisocyanurate
R10.5 = R36.5 which is reasonable.
Please pass this information on to the contractor I don't have his email on file.
Thank You,
Chuck Miller
Assistant Building Commissioner
City of Northampton
Town of Williamsburg
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