Floor TJI wood joist in the crawl space is chewed

[m1208]

Ground water table is high and crawl space soil is wet during rain season and moist during summer time. Some of the bottom chord of the floor TJI wood joists are chewed. Is it a moisture problem or insect/animal attach? This only happens in one area of the house. If it is mfr problem then it would be all over the floor.

 

[msquared48]

Looks like it occurred at a rat run where the critters were trying to get to the other side of the joist. l

I would suggest installing a sump pump and replace the rat runs with TJI blocking to brace the bottom flange, or what is left of it.

Oh yea, call Truss Joist and get their recommendation for a fix for the bottom member.

Put out rat traps too.

Mike McCann
MMC Engineering

 

[hokie66]

Looks more like termite damage to me. They love moist conditions.

 

[Ron]

Mostly wood rot, possibly some termite damage. Rat run prevented air circulation at that location, exacerbating the rot condition. Agree with Mike....contact TJ to get a repair scheme.

 

[m1208]

What is a rat run?

 

[chicopee]

I would support the existing joist at the middle, cut out about 2" from the bottom and add another TJI wood joist next to it. The cut out section would allow for the positioning of the bottom flange of the new joist.

 

[msquared48]

m1208:

In order to stabilize the bottom chord of open web trusses, continuous 2X4 or larger flat members are nailed to the top of the bottom chords. These 2X flat members are colloquially known as "rat runs". And it is a highway for them, especially if you have rats in the belfry.

The picture just reminded me of the application...

Mike McCann, PE, SE