A question about floor joists

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jos51700

jos51700

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My house had a small amount of termite evidence on a floor joist when we bought it five years ago. Inspection revealed that they were old tunnels, and were vacated, and the house had been treated. The joist in question was sistered when the house was built and the tunnels ran between a gap in the two.

I noticed that one of the two was collapsing at the end, and probing revealed the joist is very damaged up to about two feet from the basement wall. The rest is solid, at least on the outside.

I was going to prop a joist up opposite the damaged one, cut the damaged joist out, and sister in a new one. If I find damage in the original sister, I would then remove the prop joist, and cut out the sister, and permanently install the prop joist as the new sister. The span is about twelve feet, and there is an interior wall above.

Is this a bad plan? I noticed the sagging when I found a squeaky spot in the floor near that wall, but the deck seems mostly untouched by termites. i didn't know if I should just sister in a third joist and call it good. Some say to leave the original, some say to remove, and I'm unsure what plan of action to execute.


FABO's home-construction expert opinions are appreciated!
 
You to have temporarily carry the load as your replacing. Can you get away with just building a 12’ doubled joist next to it. I’m guessing you may need to jack it up if the floor is sagging.
 
jos51700 said:
My house had a small amount of termite evidence on a floor joist when we bought it five years ago. Inspection revealed that they were old tunnels, and were vacated, and the house had been treated. The joist in question was sistered when the house was built and the tunnels ran between a gap in the two.

I noticed that one of the two was collapsing at the end, and probing revealed the joist is very damaged up to about two feet from the basement wall. The rest is solid, at least on the outside.

I was going to prop a joist up opposite the damaged one, cut the damaged joist out, and sister in a new one. If I find damage in the original sister, I would then remove the prop joist, and cut out the sister, and permanently install the prop joist as the new sister. The span is about twelve feet, and there is an interior wall above.

Is this a bad plan? I noticed the sagging when I found a squeaky spot in the floor near that wall, but the deck seems mostly untouched by termites. i didn't know if I should just sister in a third joist and call it good. Some say to leave the original, some say to remove, and I'm unsure what plan of action to execute.


FABO's home-construction expert opinions are appreciated!
Click to expand...
Seems like a good plan. Could add bridging or blocking to help share the load (probably already has but if not add)
Can you probe the extent of the damage?
If so then maybe its worth dutching in a filler. That can be a lot of work but does mean the one complete joist isn't cut away.
If its a real wood (not ply etc) flooring then when you cutaway the original joist you'll have to cut the nails and no easy way to reinstall if its a modernish construction (ie subfloor).
But if the joist is gone in the pocket its doing no good.
 
jos51700 said:
My house had a small amount of termite evidence on a floor joist when we bought it five years ago. Inspection revealed that they were old tunnels, and were vacated, and the house had been treated. The joist in question was sistered when the house was built and the tunnels ran between a gap in the two.

I noticed that one of the two was collapsing at the end, and probing revealed the joist is very damaged up to about two feet from the basement wall. The rest is solid, at least on the outside.

I was going to prop a joist up opposite the damaged one, cut the damaged joist out, and sister in a new one. If I find damage in the original sister, I would then remove the prop joist, and cut out the sister, and permanently install the prop joist as the new sister. The span is about twelve feet, and there is an interior wall above.

Is this a bad plan? I noticed the sagging when I found a squeaky spot in the floor near that wall, but the deck seems mostly untouched by termites. i didn't know if I should just sister in a third joist and call it good. Some say to leave the original, some say to remove, and I'm unsure what plan of action to execute.


FABO's home-construction expert opinions are appreciated!
Click to expand...
I would just put in a third. You probably have underlayment and or flooring nailed into the existing ones
 
Mattax said:
Seems like a good plan. Could add bridging or blocking to help share the load (probably already has but if not add)
Can you probe the extent of the damage?
If so then maybe its worth dutching in a filler. That can be a lot of work but does mean the one complete joist isn't cut away.
If its a real wood (not ply etc) flooring then when you cutaway the original joist you'll have to cut the nails and no easy way to reinstall if its a modernish construction (ie subfloor).
But if the joist is gone in the pocket its doing no good.
Click to expand...

Dutching in a filler? Google gives me nothing, can you explain that?

Thanks to all for replies.
 
If you do scab on or sister a joist next to another.
It is always a good idea when there are termites or dry rot to use wood preserve treatment and cut out the rot if you can ?
The wood preserve is like glue and you brush it on.
 
jos51700 said:
Dutching in a filler? Google gives me nothing, can you explain that?

Thanks to all for replies.
Click to expand...
A dutchman is an infill piece.

This has a infill and is also sistered (on the other side)
upload_2020-4-11_15-33-35.png
 
What is the height and length of the joists, the spacing between joists, and the approximate age of the house? Some older house up to the 60's had shorter joists than have become standard, and can use more beefing up. Those undersized (by today's standards) joists will tend to have the wood fibers 'creep' with age and sag.
 
I would cut the old one out.

Multi tool or a flush cut blade on the sawzall to cut the nails. Use liquid nails on top of the new joist and screw it to the sub floor from the bottom. I use to work for a termite company and we did this every day.

What makes me crazy is the wording. Let me pass this on beacuse everyone here is saying it wrong.

You have one joist or you have 100 joist. There is NO joists. It is never plural.

And that ladys and gentlemen is your tip of the day.
:)
 
If you want to do a bang up job and cure all your problems then do this. First use a support beam that you can jack up to take the load and sag out of the floor. You want to put this an inch or two to the side of the existing joist. Next cut out the existing joist and then use a saws all to cut the flooring nails off flush with the sub-floor. Next install a new joist in the original position insuring that it is at the proper height with steel shims. It wouldn't hurt to toenail the joist at the ends and maybe put a brace block to the next joist over. Then lower the temporary support so the floor rests on the new joist. Job is done and never to be worried about again unless the termites come back.

Jack
 
4spdragtop said:
A for sale sign sounds a helluva lot easier. :poke:
Click to expand...

While I agree that the damage probably goes further than I care to think about, if your suggestion is to sell my house over some termite damage, I'm going to wager that you are one to throw your clothes away after the first/only time you wear them? :realcrazy::realcrazy::realcrazy::D
 
Only if I eat yer cookin':elmer::poke:
jos51700 said:
While I agree that the damage probably goes further than I care to think about, if your suggestion is to sell my house over some termite damage, I'm going to wager that you are one to throw your clothes away after the first/only time you wear them? :realcrazy::realcrazy::realcrazy::D
Click to expand...
 
Wait? So the plural of joist isn't joists, joistises, or joisti? I doubt I will "prolly" ever haul more than 1 joist in my Chally conv with the top down! :realcrazy::BangHead::D:p
 
4spdragtop said:
Only if I eat yer cookin':elmer::poke:
Click to expand...
I met a guy years ago that was complaining that he spent $200 a month on socks and underwear...turns out he never washed them just throws them away! He was amazed when I told him they can be washed...
 
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