text.skipToContent text.skipToNavigation

PAI/MPAI Purlin Anchors

PAI/MPAI

On This Page

Misc. Connectors for Engineered Wood

This product's information may differ depending on the category of use. You are currently viewing details related to Misc. Connectors for Engineered Wood. You can also view product information related to the category: Purlin Anchors

Purlin anchors offer solutions for wood-to-concrete and concrete-block connections which satisfy code requirements. The dual-embedment line allows installation in concrete or concrete block.

Material

  • PAI — 12 gauge; MPAI — 14 gauge

Finish

  • Galvanized.

Installation

  • Use all specified fasteners; some models have extra fastener holes. See General Notes.
  • Purlin anchor must hook around rebar.
  • Allowable loads are for a horizontal installation into the side of a concrete or masonry wall.
  • Strap may be bent one full cycle. (Bent vertical 90° then bent horizontal.)

Edge Distance — minimum concrete edge distance is 5". Minimum concrete block left-to-right edge distance is 20".

Concrete Block Wall — the minimum wall specifications are:

A — one # 4 vertical rebar, 32" long, 16" each side of anchor
B — two courses of grout-filled block above and below the anchor (no cold joints allowed)
C — a horizontal bond beam with two #4 rebars, 40" long, a maximum of two courses above or below the anchor
D — minimum masonry compressive strength, f'm = 1,500 psi

Options

  • See LTT and HTT tension ties for alternate retrofit solutions.

Related Literature

Load Tables

Wind and SDC A&B — Allowable Tension Loads (160)
Max. Ledger Size Model No. Strap Length, L (in.) Embed Length, le (in.) Uncracked Concrete Cracked Concrete GFCMU Wall Max. Allowable Strap Tension Deflection at Allowable Load (in.)
Concrete GFCMU Required Nails (in.) Tension Required Nails (in.) Tension Required Nails (in.) Tension
4x Ledger PAI18 18 1/2 4 6 (9) 0.148 x 1 1/2 1,820 (9) 0.148 x 1 1/2 1,820 (9) 0.148 x 1 1/2 1,055 NA 0.1
PAI23 23 3/4 4 6 (14) 0.148 x 1 1/2 2,835 (14) 0.148 x 1 1/2 2,260 (14) 0.148 x 1 1/2 1,805 NA 0.158
PAI28 29 4 6 (16) 0.148 x 1 1/2 3,330 (16) 0.148 x 1 1/2 2,260 (16) 0.148 x 1 1/2 2,705 NA 0.167
PAI35 35 4 6 (18) 0.148 x 1 1/2 3,330 (18) 0.148 x 1 1/2 2,260 (18) 0.148 x 1 1/2 2,815 NA 0.13
MPAI32 32 5 1/2 (16) 0.148 x 1 1/2 2,355 (16) 0.148 x 1 1/2 2,355 NA 0.167
MPAI44 44 5 1/2 (24) 0.148 x 1 1/2 2,865 (24) 0.148 x 1 1/2 2,865 NA 0.167

See Footnotes1 below

SDC C-F — Allowable Tension Loads (160)
Max. Ledger Size Model No. Strap Length, L (in.) Embed Length, le (in.) Uncracked Concrete Cracked Concrete GFCMU Wall Max. Allowable Strap Tension Deflection at Allowable Load (in.)
Concrete GFCMU Required Nails (in.) Tension Required Nails (in.) Tension Required Nails (in.) Tension
4x Ledger PAI18 18 1/2 4 6 (9) 0.148 x 1 1/2 1,820 (9) 0.148 x 1 1/2 1,820 (9) 0.148 x 1 1/2 1,055 4,180 0.1
PAI23 23 3/4 4 6 (14) 0.148 x 1 1/2 2,830 (14) 0.148 x 1 1/2 1,980 (14) 0.148 x 1 1/2 1,805 4,180 0.158
PAI28 29 4 6 (20) 0.148 x 1 1/2 2,830 (16) 0.148 x 1 1/2 1,980 (16) 0.148 x 1 1/2 2,705 5,070 0.167
PAI35 35 4 6 (20) 0.148 x 1 1/2 2,830 (18) 0.148 x 1 1/2 1,980 (18) 0.148 x 1 1/2 2,815 5,070 0.13
MPAI32 32 5 1/2 (16) 0.148 x 1 1/2 2,355 3,205 0.167
MPAI44 44 5 1/2 (24) 0.148 x 1 1/2 2,865 3,205 0.167

Footnotes1

  1. Allowable loads have been increased for wind or earthquake loading with no further increase allowed. Reduce where other loads govern.
  2. Deflection listed is at the highest allowable load.
  3. To obtain LRFD values, multiply ASD seismic load values by 1.4 and wind load values by 1.67 (1.6 for 2012 IBC).
  4. Nail quantities are based on Douglas fir (DF) or equivalent specific gravity of 0.50 or better. For use in spruce-pine-fir (SPF) or hem fir (HF), nails quantities shall be increased by 1.15 to achieve loads listed.
  5. For wall anchorage systems in SDC C-F, the maximum strap allowable load shall not be less than 1.4 times the ASD anchor design load.
  6. Minimum center-to-center spacing is 3x the required embedment — i.e., standard installation is based on a minimum 5" end distance.
  7. Structural composite lumber beams have sides that show either the wide face or the lumber strands/veneers. Values in the tables reflect installation into the wide face.
  8. Concrete shall have a minimum compressive strength of f'c = 3,000 psi.
  9. Grout-filled CMU (GFCMU) shall have a minimum compressive strength of f'm = 1,500 psi.
  10. For PAI/MPAI models, 0.148" x 1 1/2" nails shall be used directly onto framing member. For installation over sheathing, use 2 1/8"-long nails minimum.
  11. Fasteners: Nail dimensions in the table are listed diameter by length. For additional information, see Fastener Types and Sizes Specified for Simpson Strong-Tie Connectors.

Code Reports

Part IAPMO UES ER ICC-ES ESR City of Los Angeles State of Florida
MPAI32No evaluation report listing.
MPAI44No evaluation report listing.
PAI18 ESR-2920 ESR-2523 FL13326
PAI23 ESR-2920 ESR-2523 FL13326
PAI28 ESR-2920 ESR-2523 FL13326
PAI35 ESR-2920 ESR-2523 FL13326

ESR-2523 is an Index of many of Simpson Strong-Tie Stamped and Welded Cold-formed Steel Products for Wood or Cold-formed Steel Construction

Drawings

Part Orthographic Perspective
MPAI32None None
MPAI44None None
PAI18
PAI18 Front View
DWG DXF
PAI18 Left View
DWG DXF
PAI18 Right View
DWG DXF
PAI18 Installed Perspective View
DWG DXF
PAI23
PAI23 Front View
DWG DXF
PAI23 Left View
DWG DXF
PAI23 Right View
DWG DXF
PAI18 Installed Perspective View
DWG DXF
PAI28
PAI28 Front View
DWG DXF
PAI28 Left View
DWG DXF
PAI28 Right View
DWG DXF
PAI18 Installed Perspective View
DWG DXF
PAI35
PAI35 Front View
DWG DXF
PAI35 Left View
DWG DXF
PAI35 Right View
DWG DXF
PAI18 Installed Perspective View
DWG DXF