There is a gap in my joist, dear readers

[Rayray]

Hi
I am currently renovating my basement, which started with removing the kitchen, and progressed to removing the cladding ceiling, removing the ceiling above that and now removing the plaster and lathe ceiling as that is heavily damaged... However, now I have found the joists, mostly looking really good, aside one, right next to the wall... it has a gap of about 1 ft, about halfway across the length, directly below the fireplace above...

When I say gap, I don't mean notch, I mean there is no joist there. No joist. Everything in me says this is a problem... but also, everything else seems structurally sound...

Photo attached

Advice and knowledge sharing very very welcome

 

[a twig]

Is it me or are the ends charred?

 

[Kearn]

I’d be going with a very slow unintentional burn form the fire above. Our last house, had similar, except different location / the wall plate that ran above the fireplace and the spine beam that projected out from the above the fireplace, both burned through and hacked back leaving a couple of foot missing when the Victorian insurance rebuild job happened.

 

[Rayray]

Yes, it does look charred, initially I thought it was just some rot or damp prevention applied, but I screw driver prode has revelled it certainly is burnt. I've also got a couple more photos....
You can see that a wide notch has been cut into the joist, at an educated guess, this spans the width of the fire surround upstairs.
you can also see that the joist does appear to have been cut.

But why am I looking at this?

and...

I guess my question extends to, can I brace it or do I have to fully replace the joist?

 

[Cubist]

Well this is a bit of a puzzle. You say theres a fireplace more or less directly above this severed/burned joist so I'm assuming theres a brick wall rising from the basement and this joist is/would have run parallel to the wall itself. The floorboards immediately above that section look much newer than their neighbours and this has me thinking there may have been a chimney breast that may have housed a solid fuel fire that was removed consequent to a fire of some kind. What has me bemused though is the older copper pipes that run directly into that space and appear to rise into the room above. I'm guessing that these were either for a gas supply but they could just as easily be water supply and feeds to/from a solid fuel back-boiler.

I don't think there could be much disputing the nature of the original damage being caused by a small fire in that area at some time and that theres been a considerable amount of work done there in the recent past. All of which might suggest that the previous workers did not feel that the damaged joist posed much of a threat. Assuming that the joist was in effect a wall plate set almost directly beside and parallel to a brick wall it primary functions would have been to support the wooden floor immediately above and perhaps other joists mounted on it. In your shoes, and before doing anything else I would be testing to see if there is any movement - in any direction - of remaining tails of that joist. If there is none and you do not plan to add any significant weight to the floor above I would be tempted to leave well enough alone. If, on the other hand, there is some movement you might consider the use of wall anchor bolts to secure the tails firmly to the wall rather than trying to replace the entire joist.

 

[Stevers]

If there is or was a fireplace above, then there's a missing hearth structure. It's usually a sort of brick arch built between a stout timber and the wall. In our basement they've plastered one of them up into the invert of the arch and you can see where it is. The gap in your joist near the wall being where this brick work and the necessary trimming timbers would have been.

You got a like just for the title!

 

[Cubist]

You got a like just for the title!

Now you mention it - I've been wondering why it chimed with me too. Theres a Hole in My Bucket Dear Liza...
It's kinda reassuring to know though that I'm not alone in collecting dross lyrics from songs heard in youth.