Support Block (SB)


A multi-purpose engineered wood structural blocking component designed to conform to the side profile of a wood I-joist... that provides numerous functions with engineered value ratings.











  • Provides consistent vertical load performance ratings.
  • Substitutes as a pre-cut “squash block”.
  • Functions as a quick and accurate means of “stiffening” the web.
  • Protects I-joist flanges with nailing through the web only…fewer callbacks and “Red Tags”.
  • Helps protect I-joists from vertical point loads at floor perimeter inside Rim Board or mid-span. 
  • Creates a “solid-end” nailing platform to secure sub-fascia and/or Rim Board to I-joist rafter tails and cantilevered floor joists.
  • Available in 12’ lengths to CTS on site to customize special needs for retrofitting existing structures.
  • And much more… (see Product Bulletin under LITERATURE section for installation details)


Installation Tips:


#1 -- SB's are not orientation specific... and can be flipped either way.


#2 -- Once the SB is secured to the I-joist web, additional 8d nails can be used to secure the RB to the edge of the SB.  This is very useful for cantilevered floors and roof sub-fascias... where the RB needs more attachment than just one 8d nail into each of the top and bottom flanges.


#3 -- Standard sub-floor adhesive may also be utilized on contact surfaces when attaching/nailing SB's to the side of an I-joist.


In contrast to conventional field-cut 2x4 "squash blocks", the I CHOICE Support Block (SB) is secured with nails through the I-joist web... not the flanges.  The integrity of the I-joist flange is maintained, without violating the manufacturer's nailing schedule.  The SB itself also does not split when nailed... as often does a conventional 2x4 squash block.

(NOTE:  Most I-joist manufacturers prohibit sideways nailing into the flange laminations within 4-6" of the end of the I-joist... where the horizontal shear of the member is most critical.)