Floor Joist Damage & Splices

[SperlingPE]

I was asked to look at some floor joists - nominal 2x8'as @ 24" o.c. spanning 12'3". The joists are damaged at one end. The damage extends from the face of the foundation wall inward 5'. The damage is located in the bottom third of the joist. Some of the joists may have damage up further into the joist. There is likely damage at the location where the joist is in contact with the wall (bearing location).

Is it worth trying to design a splice with side plates and through bolts or just go with replacement?

My first inclination was to replace. Add new joists to carry the loads between the existing joists or along side the existing joists.

Whether splicing or replacing, there will be ducts, pipes, and wires that will need to be taken down for the installation work.

 

[KootK]

Make it Glenfiddich and throw in some howling children, and you're there.

I suspect that plain old sistering will win the day. With regard to that, 2x6 sisters would be no harder to fish through than 2x4, right? Both would go in weak axis and get flipped upright I imagine.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[pete600]

kootz,

how would you quantify the capacity of the bolts?

Should there be any concern with causing tension perpendicular to the grain caused by the bolts in the existing joist?

"God grant me the serenity, to accept the things I cannot change, the courage to change the things I can, and the wisdom to know the difference" -Reinhold Niebuhr

 

[KootK]

how would you quantify the capacity of the bolts?

Bearing, edge distances, group action factors, Hankinson formula... the usual stuff.

Should there be any concern with causing tension perpendicular to the grain caused by the bolts in the existing joist?

It would definitely be a concern in the new, moment connected members. I don't see it in the existing members.


I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.