Every single time I do an audit where the house has I joists instead of regular floor joists I see this issue. Either the insulation batts are installed with no tiger teeth at all and the batt is resting on the bottom of the joist or the installers DID use tiger teeth but those are in turn resting on the bottom of the I joist with the insulation on top. Even though I joists are still 16" OC the actual width between the wood members is greater than with typical floor joists. Tiger teeth are 16" wide and aren't long enough to properly support anything and in turn rest on the bottom of the I joist. Here in Colorado R19 is pretty standard and typical I joist heights are either 10 or 12". This results in an approximate 4 or 6" airgap above the batt and extremely ineffective or totally pointless insulation. What I'm getting at is what do most professionals recommend to remedy this? If tiger teeth aren't the right width then are people typically using twine and staples to get the R19 flush with the floor? Otherwise are people getting an additional R13 or 19 batt to fill the entire cavity and using twine and staples on the bottom of the joist to secure them in place? Does somebody manufacture oversized tiger teeth for this type of application that I'm unaware of?
Any input is appreciated as I see this all too often.