approval letter SFH 2012-06-11
James Locke June 11, 2012
26 South Street
Williamsburg, MA 01096
Subject Location/Project: 27 Fort Street / SFH
Map Block: 38B - 183
Mr. Locke
The following items are code requirements
which need to be addressed as part of this project:
Fireplace requires 2” side/front and 4” rear clearance, make-up air, 20” fire box depth and 20” hearth extension.
All non-prescriptive
materials require stamped drawings.
Air barriers before tubs or showers go against exterior walls.
Air barriers are required at band joist.
All point loads must continue to foundation
bearing points.
An initial and final HERS rating is required.
As of August 4th 2011 the 8th Edition MA code is the 2009 IRC with MA amendments.
In the following are some generic requirements
which seem to be problematic.
This is not a substitute for purchasing and reading the MA codes. 780CMR 2009 IRC with MA amendments.
Structures shall conform to 780 CMR 8th Edition 1
and 2 family building codes with MA amendments.
Grading plan for structures being constructed required. 780 CMR R401.3 for drainage requirements.
A basement drainage system is required
in all basements 780 CMR R405.2.3. except those in group I soils (table R405.1)
Foundations that retain earth and enclose interior space require damp proofing 780 CMR R406.1.
Foundation
anchor bolts must be ½” and be embedded a minimum of 7” into the concrete. 10” bolts! 780 CMR R403.1.6
Ceiling joist are intended to prevent spread, once raised above the wall plate
they become rafters ties and may require up sizing of rafters and increased nailing for example with a 4” slope 8-16nd common are required at each connection. 780 CMR R802.3.1. When
there is not one of these two a structural ridge is required with a load path to the foundation.
Steel straps over the ridge or 1x4 minimum collar ties are required 4’ OC in the upper
1/3rd 780 CMR R802.3.1
Ridge boards must be the full depth of the cut. 780 CMR R802.3.
A complete window and header schedule is required. 780 CMR Table R502.5 for header sizing and number
of jack studs required.
All framing materials which are not code prescriptive must have stamped engineering.
LVLs
I-joist and or Floor Truss
Roof truss
A braced wall plan identifying
appropriate braced wall areas and braced wall method being used. 780 CMR 602.10.
Garage corners and large corner window/door layout may require special solutions.
All corners must be appropriately attached to the foundation.
Ceiling heights minimum 7’ for habitable spaces, 6’8” for bathrooms includes tub/shower area if a shower head is used, 6’8”
for basements, 6’4” at beams/ducts. 780 CMR R305.1. MA amended
Hazardous glazing locations, within 24” of a door, or within 60” of a stair, or across from hot tubs, spas, bathtubs within
60” if not 60” above the walking surface, and other locations. 780 CMR R308.4
Windows over 72” above grade with the opening less than 24 above the finished floor shall meet the 4” sphere
rule. Order restrictors. 780 CMR R612.2
Egress and emergency escape requirements shall be strictly met.
Basements, habitable attics, and all sleeping rooms require emergency escape.
780 CMR R310
Windows within 44” of floor, DH 3.3 sqft min window size, Casement 20”x41” exception 5 sqft at 1st floor. Minimum clear opening 20”x24” or 24”x20”. 780 CMR R310.1.1
Two
doors remote as possible at the normal level of travel, opening measured from the face of the slab to the stop with door at 90 degrees, one 32” and one 28” minimum 78” high. 780 CMR
R311.2
Landing at each door 36” out and the width of the door minimum 36”, maximum step 7 ¾” from the top of the threshold and only in-swinging doors. 780 CMR R311.3
Stairs have critical
standards, make sure you know the floor finishes when planning. Minimum tread 9”, maximum riser 8 ¼”, maximum overall variance for the run is 3/8”, 4” sphere rule on risers except where
the total rise is 30” or less 780 CMR R311.7.4.3 Exception, 4 3/8” on balustrade, 6” in the triangle. Graspable rail 1 ¼” minimum and 2” maximum rail, height minimum 34” maximum 38”,
required for 4 or more risers. Landing to landing constitutes a new run. Minimum 6’8” ceiling height from nosing. 780 CMR R311.7.
Guards 36” minimum height above walking surface, a bench
is a walking surface, required for more than 30” above floor or grade within 36”, 4” sphere rule. 780 CMR R312.1.
Educate the plumber and electrician about maximum notch and hole sizes,
and placement. 780 CMR R502.8 and R602.6. In bearing studs holes not larger than 40% of a stud no closer than 5/8 to the edge, In interior non-bearing studs holes not larger than 60%
of a stud no closer than 5/8 to the edge, in bearing walls if more than 50% of a plate is cut or notched a 1 ½” 16ga. strap must extend a minimum of 6” past the cut both directions and
be nailed with 8-10d per side, or holes in joist are a maximum 1/3 the depth not closer than 2” from the top or bottom. Notches are different.
Dryer duct transition is limited to 8’
of aluminum flex and must be exposed. 780 CMR M1502.4.3
Dryer duct maximum equivalent length is 25’ including the transition section or per manufacturer’s specs. 780 CMR M1502.4.4.1,
no screwed connections.
Concealed dryer ducts are required to have a label within 6’ of the dryer connection stating the equivalent length and risk of fire. See CMR 780 M1502.4.5
Markup
air is required for any exhaust hood of 400 CFM or more. 780 CMR M1503.4
Fireplaces require all combustion air be provided from the exterior and below the firebox, duct work maintaining
1” clearance for 5’ from the duct outlet for all fireplaces
Fire and draft stopping shall be completed before rough inspection. 780 CMR R302.
Ignition barriers in place before final.
780 CMR R316.
Energy aspects shall comply with the stretch energy code. 780 CMR Appendix 115AA or 2009 IECC.
An initial HERS evaluation is required including insulation levels anticipated.
A
final HERS evaluation confirming code requirements have been met including duct testing.
Energy information including mechanical equipment posted on the electric panel.
Remodeling and
Additions can be completed in accordance with IECC 2009 with Energy Star Building Option Package.
Vapor retarders. Although these are still in the code have exceptions, one must understand that there is a difference between a vapor retarder or barrier and an air barrier. An air barrier
is intended to stop air flow (convection) a vapor retarder or barrier is intended to stop molecular moisture transfer (diffusion). A vapor retarder or barrier is effective even if there
are some holes or gaps, however an air barrier has to be absolute and complete. If air can leak through an electrical device or through a crack it follows the path of least resistance
and carries 99% of the moisture in a structure. This is evident every time one exposes fiberglass insulation and finds black insulation, which is dirt filter out of the air moving through
the insulation. 780 CMR R601.2 for vapor retarders and Table N1102.4.2 for air sealing requirements.
Unvented attic assemblies. Hot roofs are allowed, but have specific requirements
780 CMR R806.4.
Deck ledgers and post must be appropriately attached, bolts or lags. 780 CMR R502.2.2.1 Note: ThruLoks are engineered for post attachment supporting a railing.
Smoke
and CO detectors as required. 780 CMR R314 and R315.
Closets beneath stair which have doors must be drywalled with ½”. 780 CMR R302.7
Relevant items must be submitted to the building
department for approvals before inspections and or CO can be signed. Other items are intended to avoid costly issues at inspections.
Feel free to call if you have any questions. My telephone
number is 587-1240 and office hours are Monday through Friday, 8:30 am to 4:30 pm, excepting we close for walk-ins at 12:00 noon on Wednesdays. My email address is: cmiller@northamptonma.gov
Thank you for your cooperation on these matters.
Chuck Miller
City of Northampton
Assistant Commissioner and Zoning Enforcement