Sistering Tji Floor Joists

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.

Sistering tji floor joists.

When headroom permits sistering with taller joists provides more bang for the buck than sistering with same size joists. Framing lumber is the typical. My question is can floor joists be spliced or sistered properly. Doing so strengthens weak joists and can help straighten sagging joists.

This article provides step by step instructions and pictures on how to make structural repairs by sistering floor joists alongside weak joists. Tji joists are occasionally doubled to support other members or loads from above. Believe it or not this kind of poor workmanship is not that uncommon. 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. If you have sagging cracked or twisted joists which can happen in older houses this project will provide the extra support the floor needs. Fire safe construction 3 floor performance and tj pro rating 4 5 section 1. How to sister a floor joist.

Sistering joists means beefing them up with additional material. It s floor joists that are approximately 8 feet long made from 2 floor joists approximately 4 1 2 feet long. I ran across this today. Size alongside each existing joist also known as sistering the joists stiffens a floor.

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. However doing this does not fix the slant that the floor has taken since the old joists got damaged. 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.

Even though taller joists need to be notched to fit existing mudsills and support beams photo right the added depth. Take some extra time and jack the damaged area up so that the new lumber doesn t need to be notched. The long view makes the overlap seem longer but i believe the nearest one is less than a foot with very few nails. The joists are supporting a bathroom tub.

All i can find in my code.