Trimming LVL joists

[JAE]

I have an existing wood framed floor that uses 2x10's at 16" o.c. with wood decking above - plans are to use gyp board sheathing on the bottom for a ceiling.

Some of the existing joists were cut sometime in the past to allow a vertical duct to penetrate the floor at one end. Now that we are remodelling - the duct is no longer used and the duct cover-wall that had been used to support the cut joists is removed. So some of these floor joists are hanging (not extending over to the support walls (short by about 1.5 feet).

I had specified some LVL joists to be inserted between the existing joists and extend fulling from bearing wall to bearing wall. These were installed properly - everything is good - EXCEPT - we find out that the LVL's we specified are 14" deep and extend below the existing joists.

I have reviewed the design of these LVL (lamenar veneer lumber) joists and if I cut them to 9.5" deep they still work (I was very conservative in my original calculations). They work in both shear and flexure and deflection.

I'm just checking here with you all as to any concerns there might be to trim off the bottom 4.5 inches of these joists so they line up with the existing joists. Any comments? The cut would be horizontal all the way to the bearing wall (brick multi-wythe wall) and then turn downward such that the joist "in" the wall would still be 14" and the joist beyond the face of the wall (between the faces) would be 9.5".

 

[RARWOOD]

You need to check with the company that made the LVL (laminated veneer lumber).

I believe you should be able to trim LVL down to a smaller size with out effecting the design properties. I think in many cases when they make LVL they make it in larger widths, such as 4', and then use a gang saw to cut it into a number of smaller pieces.

However, all of this type of products are proprietary so you do need to check with the manufacturer.

The one item which might be a problem is the 14" depth at the support. I don't know if you would have stress risers due to the notch.

 

[FSS]

Ripping LVL beams to proper depth is not a problem. Check with manufacturer or supplier and they should point you to their literature where it gives OK. This happens a lot for us with remodels when their standard sizes do not match field depths required.