Home Foundation Design - Anchor Bolt Installation

Introduction

• This e-article is about installing anchor bolts in designing a home foundation
• Guidelines to follow are an accumulation and amalgam of the literature and work at the granite knee of life experience 

Anchor Bolt Installation

• For wood stud wall anchorage, anchor bolts
  • shall be placed in all exterior grade beams and
  • shall be placed in those interior grade beams supporting bearing walls
  • shall be a j-bolt
    • with j-hooks only faced to greater cover

Comment:  L-hooks'll do, but not preferably.  This custom home designer thinks it's preferable not to relatively weaken every other anchor bolt by pointing to lesser cover and it's preferable to run the rebar down through the "j"s than tie-off "l"s to them.

• shall not be less than 5/8 linear inch diameter

Comment:  Forget about 1/2 linear inch diameter anchor bolts by the same token that you can forget about 1/2 linear inch exterior wall sheathing and roof sheathing 

• shall be fortified with a continuous #5 rebar over the short bend
• shall be galvanized or otherwise appropriate to the wood preservative used to treat the mudsill or sill plate, noting that
  • if borate (a/k/a dot, or disodium octaborate tetrahydrate) is the wood preservative, then the wood so preservative-treated shall be applied only in persistently dry areas, e.g.,
    • most mudsills or sill plates, unless otherwise noted and
  • no special materials are required either to coat or comprise the fasteners, flashings, etc. beyond those applied either to untreated lumber or CCA (chromated copper arsenate)-treated lumber
• shall be in embed depth not less than 12 times diameter, or about 7.5 linear inches, unless otherwise noted for deeper embed
• shall be spaced at
  • not greater than 48 linear inches on center commonly and 

• not greater than 16 linear inches on center in
• high wind-resistance area
• seismic zone 2B and up

Comment:  This even tighter spacing is to mitigate agains sills' splitting.

• not greater than 9-12 linear inches from
• either side of any corner
• the interior wall side(s) of any intersection(s)
• any butt
• either side of a beam pocket
• not less than 2 per member
• shall bear using suitable Simpson bearing plate BPS or LBPS 3 linear inches x3 linear inches or not less than equivalent in lieu of flat or other washers
• shall not be less than most recent ASTM a-307 (a/k/a American Society for Testing and Materials, "Carbon steel bolts, studs, 65,000psi pencil straight, externally threaded fasteners")
• shall be specifically, expressly suitable for application with chosen wood preservative
• such bolt shall penetrate
  • 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 and
  • 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
• such bolt's hex nut shall be run home by wrenching
  • which wrenching shall pock but not penetrate sill surface 
• In a Foundation Plan, this custom home designer
  • draws in anchor bolts one at a time in plan view
    • shank, head-on
    • big, square bearing plate
    • hex nut
  • foundation designing-in conformance with precepts herewith 

Foundation Plan, Excerpt, Highlighting Designing-In Anchor Bolts

 Comment:  Takes the guesswork out of figuring about where and how many anchor bolts will do. 

Comment:  Optionally and with the consent of your local building authority having jurisdiction, you may consider Simpson Strong-Tie's mas mudsill anchor as a simple, cheap alternative.  http://www.strongtie.com 

• Other types of anchors
  • shall be acceptable, such as
    • powder-actuated fasteners
    • drilled epoxy anchors and
    • mudsill anchors
  • depending on
    • nature and character of application and
    • subject to local authority having jurisdiction
  • except that extreme care must be taken with applications involving
    • existing substandard, placed concrete, e.g., some WWII residential placements, wherein
    • any CMU, or concrete masonry unit, or brick and block
  • whereby
    • dowels and anchors shall not be driven or expanded but rather drilled and doweled
    • spacing for the alternative anchors shall be determined using the shear capacity and uplift load for 5/8 linear inch diameter anchor bolts
    • specifications may be done by others

• Note that each 5/8 linear inch diameter anchor bolt
  • shall have a shear capacity of not less than 1,500 pounds and
  • shall resist an uplift load of not less than 1,400 pounds
  • spacing for the alternative anchors shall not exceed the spacing for the 5/8 linear inch diameter anchor bolts specified above