I was looking at using TJI Joists to join roof panels to improve roof long term rigidity and run longer spans.  However my roof panels will have a foam depth of only 9-3/8-inch while the closest TJI joist I find is 9-1/2.  Can anyone comment on how this is done?

Thanks

Chuck;

it may be necessary to rip the spline, this is one of the frustrations I always had with OSB sips and dimensional lumber, very often needing to rip PT plates as they swelled up too much when saturated.
This is one of the many reasons I eventually switched to steel SIPs that are dimensionally precise and do not use splines at all, simply snaping together

Chuck,

Check with your SIP manufacturer about using TJI splines or “I” splines. Many manufacturers supply TJIs which are the correct depth for their panels. Some install foam on either side of the web to create a rectangle cross section to simplify panel fabrication and installation. Also, roofs need to be engineered, either by using published span tables from the manufacturer or by an engineer. Arbitrarily installing TJI’s will increase the allowable loads of the roof and reduce deflections, but if they will work in your situation needs to be looked at. If the SIP supplier you are using does not supply “I” splines and/or can not provide load tables for roofs using “I” splines. I would suggest finding another SIP supplier for your roof panels.

chuck,

the opposite approach is also true. we had panels made for a church to accomodate beams that were already a spec for the project. you might ask your sip supplier to give you custom thickness of the panels. the rim board for the joists should then fit to cap your panels as well.