Basic principles for Triforce® floor sytem installation

Here are some basic principles for Triforce® floor system installation. If you are new to this advanced product, you’ll be happy to know it isn’t complicated at all.

Keep the block end of the joist on the straightest run during floor system installation

Triforce® has a block end and an adjustable end. The adjustable end consists of 34 1/8” of OSB paneling between the upper and lower chords, 24” of which is adjustable. The block end consists of a 2 x 3 connection to the upper and lower chords.


Installing the block end on the straightest run ensures that the joist webs are all lined up. This, in turn, makes the installation of plumbing runs and HVAC ductwork easier. This is because a perfectly straight installation eliminates the need to have jogs (small deviations in direction) within the plumbing or HVAC, which, in the case of plumbing, could create unnecessary impediments to the flow of water, and make the whole system less efficient.

The straightest run can usually be on the inside (on an interior beam), or on the outside walls. The interior bearing wall is best to accommodate the block end.  This way, the adjustable end of the joist will be on the outside wall, making it easier to set and adjust.

Adhere to on-center spacing

More basic principles. Being as consistent as possible with on-center spacing will help the floor system installation and the installation of the sheathing that goes on top of the joists. If the joist spacing isn’t perfectly uniform, the sheathing seams may not match up with the top chords of the joists. If that’s the case, it’ll be necessary to add to the joists in order to have something to nail to, such as ladder blocking. In the example below, the ladder blocking is used for a non-load-bearing interior wall, but it’s the same principle for sheathing.

Screen Shot 2016-11-22 at 12.03.17 PM

You’ll notice that we recommend  using a “Z” bracket to connect the 2 x 4.

Screen Shot 2016-11-22 at 12.11.39 PM

I’ve also seen builders chose an alternative such as nailing a 2×4 under the top chords and then nailing a second 2×4 on top of that. Another alternative would be to affix sections of I-joist nailed into the top and bottom chords. For safety’s sake, I would still go with the bracket.

Establish plumbing penetrations as early as possible in the design process

If you are working with a plan drawn up by an engineer of record then the locations of the toilet, tub, and sinks are quite specific.  And so will the locations of the plumbing penetrations. Plans drawn up by commercial designers, however, sometimes don’t include all the walls or specific locations of plumbing penetrations. If this is the case, we have to recommend that these details be added to the plan before construction starts. This can be done by a structural engineer, or even the manufacturer may be willing to help. The idea is to make sure that the penetrations never interfere with the joists. If possible, make sure they don’t interfere with their spacing either.

That said, it is possible to move one joist over a couple of inches, if necessary. It won’t affect the floor’s performance.

Those are the basic principles for Triforce® floor system installation.  Make sure to keep them in mind if you’re building with Triforce®. If you haven’t yet and would like to find out more about the Triforce® product, then please download our spec guide now!

Triforce Spec Guide

No Comments Yet.

Leave a comment