Chimney breast removal and joists exposured

[Moeen ahmed]

Hi all. I'm new here, please go easy on me. I need you all the chippys, architect and builders advice on board and ASAP.

I've removed my chimney breast walls from top to bottom. I'm now left in the bedrooms with exposed Joists, which are 7x3 timber and 5 metres long.

I was hoping, is it possible not to use joists hangers, but rather wall to wall joist by sistering them? The original old joists go wall to wall, then the other joists join in them in cross hatch style, like a joist hanger version.....

I can bring up the new Joist timbers into bedrooms no problem at all, as I have plenty of space to move around and the the house is under renovation.

Should I use 7x3 or 8x3 joist timber c24.

I hope this information helps and it was clear,, if you need pictures or explaining. Please get back to me asap or text me on REMOVED

Thanks,
Moe.

 

[Moeen ahmed]

Hi all. I'm new here, please go easy on me. I need you all the chippys, architect and builders advice on board and ASAP.

I've removed my chimney breast walls from top to bottom. I'm now left in the bedrooms with exposed Joists, which are 7x3 timber and 5 metres long.

I was hoping, is it possible not to use joists hangers, but rather wall to wall joist by sistering them? The original old joists go wall to wall, then the other joists join in them in cross hatch style, like a joist hanger version.....

I can bring up the new Joist timbers into bedrooms no problem at all, as I have plenty of space to move around and the the house is under renovation.

Should I use 7x3 or 8x3 joist timber c24.

I hope this information helps and it was clear,, if you need pictures or explaining. Please get back to me asap or text me on REMOVED

Thanks,
Moe.

 

[Moeen ahmed]

Hi all. I'm new here, please go easy on me. I need you all the chippys, architect and builders advice on board and ASAP.

I've removed my chimney breast walls from top to bottom. I'm now left in the bedrooms with exposed Joists, which are 7x3 timber and 5 metres long.

I was hoping, is it possible not to use joists hangers, but rather wall to wall joist by sistering them? The original old joists go wall to wall, then the other joists join in them in cross hatch style, like a joist hanger version.....

I can bring up the new Joist timbers into bedrooms no problem at all, as I have plenty of space to move around and the the house is under renovation.

Should I use 7x3 or 8x3 joist timber c24.

I hope this information helps and it was clear,, if you need pictures or explaining. Please get back to me asap or text me on
REMOVED

Thanks,
Moe.

 

[Moeen ahmed]

Hi all. I'm new here, please go easy on me. I need you all the chippys, architect and builders advice on board and ASAP.

I've removed my chimney breast walls from top to bottom. I'm now left in the bedrooms with exposed Joists, which are 7x3 timber and 5 metres long.

I was hoping, is it possible not to use joists hangers, but rather wall to wall joist by sistering them? The original old joists go wall to wall, then the other joists join in them in cross hatch style, like a joist hanger version.....

I can bring up the new Joist timbers into bedrooms no problem at all, as I have plenty of space to move around and the the house is under renovation.

Should I use 7x3 or 8x3 joist timber c24.

I hope this information helps and it was clear,, if you need pictures or explaining. Please get back to me asap or text me on **********

Thanks,
Moe.

 

[Deleted member 174758]

I'm now left in the bedrooms with exposed Joists, which are 7x3 timber and 5 metres long...

I was hoping, is it possible not to use joists hangers, but rather wall to wall joist by sistering them?...

Should I use 7x3 or 8x3 joist timber c24.

As far as I can see there are two ways to go about this:

1. Start by infilling the existing masonry pockets with brick cuts and mortar. Bolt a 7 x 2in (or 7 x 3in if you want) C16 ledger to the wall ideally with joist hangers already attached, extend the original joists by bolting 7 x 3 sistering joists to them (1 metre minimum overlap with holes at maximum of 600mm centres and 100mm in from the ends, M12 x 180mm bolts with dog washers in the middle and large square washers at the outsides), fill every nail hole in the hangers with a twist nail. If bolting the ledger consider resin anchors as they work well on old brickwork and tend to work more consistently than Rawlbolts

2. Widen the existing masonry pockets (chop out brick work) by about 80mm, sister the joist ends as above (but long enough to give at least 70mm of bearing onto the masonry in the pocket), pack out beneath the new joist ends with mortar and broken slate or concrete slips and mortar, brick-in the rest of the pockets

If your existing timbers are 7 x 3in then the sistering timbers should be the same cross section. In a domestic property a C16 grade timber should suffice

 

[tell80]

You appear to have demolished things and removed supporting details without knowing what you were doing or what you were going to do next - this way of going on could be dangerous to you.

From what I could see, for instance, there's no need for long lengths of new joist, there are much simpler ways of supporting short joist bolt-ons to a ledger.
You have, after a fashion, begun to hang odd bits of drywall while still demolishing and propping.
Removing chimney breasts (and roof stacks?) requires working to a number of Regulations under a permit and BCO supervision.

You need professional eyes on site.

 

[tell80]

Why not ask the mods to join all your posts here on building?

 

[tony1851]

Why put full-length joists in? why not just fill in the void with shorter pieces?

 

[John D v2.0]

In our case the spec was just to infill in the space where the chimney was with some short joists. However i can't quite work out why in your photo there seem to be joists that are too short to reach a support. Were they bearing directly on the chimney before?

 

[Moeen ahmed]

In our case the spec was just to infill in the space where the chimney was with some short joists. However i can't quite work out why in your photo there seem to be joists that are too short to reach a support. Were they bearing directly on the chimney before?

Hi John D,

Thank for relying on the post... The picture of the joists that are short spanned with the staircase, is that joists were joined under a chimney breast in a 'U' shape bridge ...

Iv uploaded some original pictures before of the chimney breast removal. I hope this helps...

 

[Moeen ahmed]

Why put full-length joists in? why not just fill in the void with shorter pieces?

I assumed the longer the joist bolted next to each other,, the more secure it would be? If you are saying shorter pieces, how long the shorter pieces are we saying????

 

[Moeen ahmed]

As far as I can see there are two ways to go about this:

1. Start by infilling the existing masonry pockets with brick cuts and mortar. Bolt a 7 x 2in (or 7 x 3in if you want) C16 ledger to the wall ideally with joist hangers already attached, extend the original joists by bolting 7 x 3 sistering joists to them (1 metre minimum overlap with holes at maximum of 600mm centres and 100mm in from the ends, M12 x 180mm bolts with dog washers in the middle and large square washers at the outsides), fill every nail hole in the hangers with a twist nail. If bolting the ledger consider resin anchors as they work well on old brickwork and tend to work more consistently than Rawlbolts

2. Widen the existing masonry pockets (chop out brick work) by about 80mm, sister the joist ends as above (but long enough to give at least 70mm of bearing onto the masonry in the pocket), pack out beneath the new joist ends with mortar and broken slate or concrete slips and mortar, brick-in the rest of the pockets

If your existing timbers are 7 x 3in then the sistering timbers should be the same cross section. In a domestic property a C16 grade timber should suffice

Hi pal. Thanks for replying to the post. I understand what you are saying... In the picture I have uploaded. Would it be better if I took out the joist trimmer, and put new 7x3 timbers sistered next to the old timbers into the wall???? is that possible??

 

[blup]

One of those half joists is sitting on a brick, that alone might have taken the weight of the hearth, although there is pocket in the wall to the right of it. The main floor joists are supported by the trimmer. As said BC approval is needed.

Blup

 

[Deleted member 174758]

I understand what you are saying... In the picture I have uploaded. Would it be better if I took out the joist trimmer, and put new 7x3 timbers sistered next to the old timbers into the wall???? is that possible??

Yes. You need to support the joists with two Acrow props and scaffolding boards, then sister the joists with same size material. The reason is one of practicality - you can't easily get a breaker into a narrow gap to form the pockets, and it will also be difficult to even get a ledger in ther and drill it to fix to the wall with the existing trimmer in place. You could always consider adding another joist parallel to the existing trimmer, which would be the easiest thing to do, but you'd possibly end up with a bouncier section of floor where the main joists terminate in the trimmer, so not an iodeal option IMHO

 

[cdbe]

You just need to extend the joists above the stairwell to reach the wall, they don't look very long so won't need much. I would be more concerned about what appears to be some fairly inadequate bearing for one of the trimmers, I would get that propped and sorted out:

Given that it's an old house it might be worth checking the existing joists while they are exposed as the span seems quite long - not unusual for them to have been excessively notched in the past resulting in springy floors, similarly if you have plans to divide the room, install a bathroom etc then consider the extra loading.