Extending joists

27 Sep 2011
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United Kingdom
Hi folks I'm in the middle of renovating my house and have a quick joist question if anyone has any advice?

So basically the house is two cottages knocked into one. The old stairs have been removed however the wall that supported the stairs remains. There are no interior walls on the floor above the only thing the old stair wall is now supporting are the joists for the ceiling of the ground floor/floor of the first floor (if you follow me).

So basically I want to remove this wall and figure to do this I need to extend the three joists currently supported by the wall. Searching this site it sounds like the options are install a trimmer or extend the joists. I'm leaning towards extending the joists as it seems like the joists supporting the trimmer would have to handle a lot of weight (three joists). But then a trimmer would support roughly the same weight say when a chimney breast was removed for example... so which one would be best?

Thoughts/advice appreciated - cheers!
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If you remove the wall in the pic you will have to first lintel over. The lintel will carry the weight of joists/floors from both sides of the wall.

To understand the lintelling process then research on here.
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Not that I would want to cut corners but isn't a lintel overkill? We're talking three joists not an entire room. Out of interest why would you not extend the existing joists?
After some research I'm planning on extending the joists. Fresh joists same size as existing (either hangers or dug in) on exterior wall, 5 foot overlap with existing joists, 8 M12 bolts per joists with square washers and timber dog connectors.

Sound OK?
Be careful if using toothed connectors between the sides of the beams.
When drawing the beams together, the force needed to cause the teeth to bite into the timber can sometimes strip the thread of the bolts.

To overcome this it is good practice to drill right through the pair of beams, then tighten them together with a piece of high-tensile threaded bar. Once together, remove the bar and insert an ordinary threaded bar, and tighten up.
Impossible to say without knowing loading, joist sizes, spans etc... A job for a structural engineer.
I can count four or five joists and counting ...? The pic also shows a lintel in-situ- what will support the lintel bearing end when the wall goes?

Few BCO's in my experience would approve remedial bolt-ons in a first floor, esp. when the floor looks a bit ramshackle, & possibly previously repaired to begin with.

Its difficult to offer a safe suggestion without dimensions and a floor plan - is the house almost a shell & where are the stairs, do the joists run from outside wall to outside wall?
I can count four or five joists and counting ...? The pic also shows a lintel in-situ- what will support the lintel bearing end when the wall goes?

Sorry I haven't been too clear. So basically I have two houses knocked into one. The room shown is the entire ground floor of one original house. The wooden beam you can see was the old entrance (with old front door boarded up beyond) and the wall I'm hoping to remove used to support the stairs of the old house (long since removed). The joists going over the beam are complete (i.e. end to end) and aren't supported by the beam itself (only three joists are supported - by the wall). All complete joists go from end to end (outside wall to outside wall).

I agree the floor is ramshackle - it's hard to make out from the pictures but the original front door has been used as section of floor board for the room above :) . I'm not sure when this was done but the house itself is a couple of hundred years old - the joists aren't that old but they aren't brand new.

The room also has two full beams each running opposite to the joists (both beams about 2/3's of the way in the room). So one beam would also provide support to one end of the new joists while the other end would be supported by the external wall. I'm thinking that all joists passing over the wall will be reinforced with new timber.
To be on the safe side I've got a structural engineer coming over this afternoon to have a look.

Thanks all!

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