Coffey - Structural LetterWESTSHORE
DESIGN ENGINEERS, P.C.
6279 JOHNSTON RD.
ALBANY Ϳ NEW YORK Ϳ 12203
WestShore Design Engineers ۅ 6279 Johnston Rd. ۅ Albany, NY 12203
Subject: Coffey Residence
38-40 Vernon St.
Northampton, MA
To Whom It May Concern,
The following references the Coffey Residence in Northampton, MA:
1. Existing roof framing:
Roofs 1,2: Conventional framing is 2x6 at 24”o.c. with a 12’ max. span (horizontal rafter
projection). Roof 2 is capable to support all the loads that are indicated below for this photovoltaic
project. Roof 1 will be capable after installing new collar ties between rafters without existing
collar ties at 1/3 of the rafter length from the ridge below the solar panel array.
2. Roof Loading:
- 4psf dead load (modules plus mounting hardware)
- 40psf ground snow load
- 5.7psf roof materials (1.7psf 2x6, 1.5psf sheathing, 2.5psf asphalt shingles)
- Exposure Category B, 125mph wind (3 sec.)
This installation design will be in general conformance to the manufacturer’s specifications, and complies
with all applicable laws, codes, and ordinances, specifically the International Building Code/IBC 2015
and International Residential Code/IRC 2015 including all MA regulations and amendments. The spacing
and fastening of the mounting brackets is to have a maximum of 48”o.c. span between mounting brackets,
staggered, and secured using 5/16” diameter corrosive resistant steel lag bolts.
Thank you.
Westshore Design Engineers
October 30, 2024
John Eibert Nicolas Nitti, PE
Director of Solar Operations. President
To: Insight Solar
59C North St.
Hatfield, MA 01038
Date: October 30, 2024
Ref.: 24101242