Sistering Tji Floor Joists

Here is a pathetic attempt to splice some floor joists under the bathroom.

Sistering tji floor joists.

Sistering joists means beefing them up with additional material. Depending on how the load is applied it may be necessary to connect the two joists together with a filler block. Drooping and joist sag can be seen in the photo. 9 16 tji joists design properties 6 floor span and load tables 7 8 tips for preventing floor noise 8 allowable holes 9 cantilevers 10 11 roof span and load tables 12 13 framing.

Tji joists are occasionally doubled to support other members or loads from above. The joists are supporting a bathroom tub. Framing lumber is the typical. Doing so strengthens weak joists and can help straighten sagging joists.

Size alongside each existing joist also known as sistering the joists stiffens a floor. My question is can floor joists be spliced or sistered properly. Take some extra time and jack the damaged area up so that the new lumber doesn t need to be notched. If you have sagging cracked or twisted joists which can happen in older houses this project will provide the extra support the floor needs.

I ran across this today. However doing this does not fix the slant that the floor has taken since the old joists got damaged. Trus joist tji joist specifier s guide tj 4000 july 2019. Believe it or not this kind of poor workmanship is not that uncommon.

Fire safe construction 3 floor performance and tj pro rating 4 5 section 1. The long view makes the overlap seem longer but i believe the nearest one is less than a foot with very few nails. All i can find in my code. In situations when sistering damaged floor joists with lumber of similar dimensions it can be easy to notch and slide the sister board into place.

Even though taller joists need to be notched to fit existing mudsills and support beams photo right the added depth. Where the two pieces of floor joist meet they aren t nailed together or have one or two nails. However if the loading is applied from above through floor sheathing through a load bearing wall or post that rests on both joists then no attachment between joists is required. When headroom permits sistering with taller joists provides more bang for the buck than sistering with same size joists.

This article provides step by step instructions and pictures on how to make structural repairs by sistering floor joists alongside weak joists.