Compression Blocks Required?

Does this application of Engineered Floor Joist with aspenite web require compression blocks at the ends?

Typically squash blocks are required where a load bearing was is above…

More info:

Hi Bryce,

From here it doesn’t even look like the bottom of the engineered joist is even touching the Iron…but if it is I wouldn’t think so if the correct Joist Hangers were used, which does not look to be the case either.

Wow - looks like those joists are bring held only by a couple of 8d nail at the top of the joist hangers. Not good!

It’s probably a Top Flange Hanger and the nails are not visible.

the only way too make a determination is by reviewing the engineered truss drawings which would be included with the original construction documents and is required to list the attachments for each member. with that said typically minimum bearing for a joist would be 1.5" over wood or metal and 3" over masonry or by an approved joist hanger.

If these I joists were butted up against another I joist I believe there is a requirement for there to be backer / filler blocks to fill in the voids at the end of the I joists. As this is set up, the bottom of the I joist are just basically hanging; could be flexed / deflected from side to side. Not saying these are “wrong”, just not as right as it could have been. Seems to be a wasted opportunity regarding what with the availability of the steel I beams. A chance to really overbuild and end up with an awesome floor frame. Would be very costly and labor intensive to go back and retrofit now.

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I think the questioner is referring to “web stiffeners”, and whether they are required or not will be found in the joist manufacturer’s literature. My guess is, probably not.

If that is what he is after, it doesn’t look like they are needed there.


…and scroll down to:

Builder Tips: I-Joist Web Stiffeners

Those are top mount hangers which do not require compression blocks…also these type of hangers are nailed from the top therefore they are most likely covered by the sheathing substrate… no comment on what nails were used being that pictures do not clearly show what they are.

Packing out the I-joist and/or I beam is overkill.


Thanks guys. This is what I like about this site.


Bryce Jeffey