BEFORE THE ARCHITECT – HOME DESIGNING BACKGROUND – UNIQUE HOME DESIGNING ARTICLES
HOME DESIGN SAFETY - FASTENING
By Before The Architect Copyright 2005-2009 Before The Architect
'tis an odd take on the subject of fastening, 'tisn't it . . .
INTRODUCTION
1) Toe-nailing shall not be a method for permanently fastening anything to anything else
2) Toe-nailing for permanent fastening in each application requires additional metal strap, tie, brace, connector, or equivalent
3) Framing members shall be spaced not greater than 16 linear inches on center
4) A framing member shall be not less than a 2 linear inches
5) Fastening anything to anything else shall be by not less than 2 face nails, two screws or bolts at 90° to fastened material, or Simpson Strong-Tie connectors, fasteners, hangers, etc.
6) Carriages bolts shall be applied as fasteners for ledgers
a) galvanized – bolt, washers, and nut
b) at not less than 5/8 linear inch diameter
c) at not greater than 16 linear inches on center
d) into pre-drilled holes not less than 1/32 linear inch and not greater than 1/16 linear inch larger than bolt diameter and
e) when lag screws must be used instead of carriage bolt, then
i) no 2 such screws shall be applied sequentially
ii) such screw shall penetrate
(1) not less than the depth of the in-lieu carriage bolt
(2) not less than 1/2 linear inch clear-through where applicable
(3) in a hole predrilled to unthreaded depth and in diameter not less than 1/32 linear inch and not greater than 1/16 linear inch larger than the unthreaded shank’s diameter
(4) in a hole predrilled for the threaded depth in diameter not less than 1/32 linear inch and not greater than 1/16 linear inch narrower than the threaded shank’s root diameter
(i) such screw shall be run home by wrenching and not by hammering
(ii) not more than 1 such screw shall be applied in a 4 linear feet span
iii) in any case – whether screw or bolt – shall be in conformance with not less than applicable standards in the Fastening Design Standards, section head below, GENERAL SPECIFICATIONS FOR FASTENERS TO MEMBERS PRESERVATIVE-TREATED W/ ALKALINE COPPER QUAT (ACQ Types A and B), COPPER AZOLE (CBA-A & CA-B). etc. applicable to wood deck members, mudsills and other members in contact with concrete, e.g., pocketed beams, floor joists, floor trusses, etc. or subject to atmospheric exposure, e.g., porch posts, framing lumber, plywood, furring strips, mouldings, etc.
(1) adaptation to which newer preservatives shall include
(a) prohibition of aluminum flashing
(b) application optionally of either stainless steel or copper flashing
(c) Note that if borate (a/k/a DOT, or disodium octaborate tetrahydrate) is the wood preservative
(i) the wood so preservative-treated shall be applied only in persistently dry areas, e.g., most mudsills or sill plates, unless otherwise noted and
1. no special materials are required either to coat or comprise the fasteners, flashings, etc.
2. beyond those applied either to untreated lumber or CCA (chromated copper arsenate)-treated lumber
iv) in any case – whether screw or bolt – shall not be offset to structure by stacked washers or any other material, except moisture impermeable barrier material
9) Joist and beam hangers to deck ledger shall not be less than in full-depth specification in conformance to joist and beam nominal depth, absolutely
10)A rim board shall be a prohibited material for fastening a ledger without express compensations to structure as developed by a qualified engineer or, in some cases, a master carpenter
11) Metal hangers
a) shall be fastened
i) with not less than 10d nails when more than 1 member is hung, and
ii) with not less than 16d nails when more than 1 member hung (except that Simpson Strong-Tie SDS screws may be applied with Simpson Strong-Tie connectors in accord with manufacturer’s specifications, or where ductile strength is a significant structural issue, e.g., seismic applications)
iii) failing which, nails applied shall be in diameter not less than a 10d common galvanized nail
b) nails applied shall not be less than 1 1/2 linear inch in length overall
c) for single-member hangers, allowable spans shall be reduced by not less than 77%
d) for double-member hangers, allowable spans shall be reduced by not less than 64%
e) shall be applied only to full depth of supported member
12) Narrow return, or weak returns (e.g., short walls at corners on one or both sides of a garage or garage vehicle doors)
a) shall be defined as
i) an exterior wall at a corner (usually next to a garage door)
ii) less than 3 linear feet wide
b) shall be braced and fastened to code, except that
i) nailing shall be with not less than 16d sinkers
ii) anchor bolts
(1) shall not be less than 2 per braced wall segment and
(2) shall not be greater than 2 linear feet apart on center
(3) shall not be less than 5/8 linear inch in diameter and
(4) shall be not less than 15 diameters embed (about 10 linear inches)
(a) nailing patterns shall be at 4 linear inches on center
(i) on both vertical and
(ii) horizontal
(iii) through sheathing
(iv) to EACH MEMBER
(v) including header and
(vi) EACH stud
(b) tight to top plates in a braced wall segment or cripple studs set in common spacing and flush to both jack, or trimmer, or jamb studs
(c) steel-strapped securely fastened to both top plates, header, and not less than 18 linear inches of jamb, or jack, or trimmer stud(s) at each end
(d) holdowns shall be at both cornered faces and not just the short face
(e) braced interiors' walls at L1 and L2 and above shall be
(i) membered and
(ii) fastened as in immediately above
(iii) except that let-in braces may be applied in lieu of ply sheathing and
(iv) wall board shall be fastened with screws at relaxed patterns
(f) braced exterior walls on levels above L1
(i) shall be membered and
(ii) fastened as in immediately above
(iii) except that not less than 5/8 linear inch carriage bolts may be applied
(iv) in lieu of anchor bolts
c) steel strap may be omitted for lack of depth in the crossing angle
d) solid, full-depth blocking shall be at thirds
e) the proximate header
i) shall be extended tight to the 4-stud corner and
ii) supported at its terminus by not less than 1 jack stud
f) the preservative-treated sill plate or mudsill shall be tripled
i) therewith requiring a longer pair of anchor bolts
ii) therewith requiring a longer hold-down
iii) which extra two members shall be set BETWEEN studs and NOT BELOW them
g) plywood sheathing shall extend not less than 4 linear feet from the weak return’s interior jack stud
i) with not less than 16d deformed, galvanized nails
ii) at not greater than 6 linear inches on center both ways
Comment: Consider relaxing fastening patterns in seismic zones over 2B, consulting with seismic-qualified engineer
13) Exterior wall bracing on L1 shall be fastened to code, except that
a) nailing shall be with not less than 16d sinkers
b) anchor bolts
i) shall not be less than 2 per braced wall segment and
ii) shall not be greater than 2 linear feet apart on center
iii) shall not be less than 5/8 linear inch in diameter and
iv) not less than 15 diameters embed (about 10 linear inches)
c) nailing patterns shall be at 4 linear inches on center
i) on both vertical and
ii) horizontal
iii) through sheathing
iv) to EACH MEMBER
v) including header and
vi) EACH stud
vii) tight to top plates in a braced wall segment or cripple studs set in common spacing and flush to both jack, or trimmer, or jamb studs
viii) steel-strapped securely fastened to both top plates, header, and not less than 18 linear inches of jamb, or jack, or trimmer stud(s) at each end
d) holdowns shall be at both cornered faces and not just the short face
e) interior wall bracing at L1 and L2 and above shall be
i) membered and
ii) fastened as in immediately above
iii) except that
(1) let-in braces may be applied in lieu of ply sheathing and
(2) wall board shall be fastened with screws at relaxed patterns.
14) Exterior wall bracing on levels above L1
a) shall be membered and
b) fastened as in immediately above
c) except that not less than 5/8 linear inch carriage bolts may be applied
in lieu of anchor bolts
. . . . . . .
About Us ◊ jrp2h2000@yahoo.com ◊ 770-889-6964 ◊ Site Map • Privacy Policy
· · · · · · ·
(If this is your first visit to Before The Architect, please consider spending a few moments looking over the Site Map, in design of a custom home, plans, the home designers, about builders and building. Before The Architect E-mail: jrp2h2000@yahoo.com.)