breaking through question..

[needmorstuff]

I am having a 2 storey extension built off my kitchen. There used to be a conservatory where the new extension is so we have patio doors there. I will need to breakthrough at some stage making the opening wider and taking it up as high as possible at the same time...

My bricky wants 1st floor joists and floor up to work off at the weekend as he is nearly up to joist level. However where the floor joists are to be installed will block access for any future chance of getting a lintel in to support the opening.

The opening is to 2.5m so I would need a lintel/rsj whatever of 2.8m.

Is it plausible to install an IG or other BOX beam lintel just in the outer course of brick now but not breakthrough? then install the floor joists and chipboard? Later down the line I could then put another box beam on the internal block skin and then breakthrough?

or does anyone have any other ideas?

really appreciate any replies you guys/gals may have for me.

 

[tomfe]

Yes, or you could put in a cavity lintel and leave all the brick/ block work below and just temporary block the small hole made.

 

[^woody^]

Why is he working off joists and not scaffold?

 

[needmorstuff]

we're putting scaffold on the exterior of the building, but i'm not sure why not the inside.. maybe costs? I would prefer to not to go the whole hog and drop in the cavity lintel as I'm not geared up to knocking through yet - I don't have any of the other trades required to hand (spark / plumber etc.) and dont want the mess at this stage. I just wanted a sanity check from you guys/gals.. I will speak to BC and see what they say.

thanks.

 

[Hugh Jaleak]

Could the lintel just be laid across the joists for now, so its there ready for when required?

 

[needmorstuff]

its the access to install it later down the line that's the issue.. if the floor is in and boarded it would be nigh on impossible to get a lintel in.

I just spoke to BC - he said its perfectly fine to put a lintel in the exterior now and another one internally later on. He suggested a catnic lintel and this at the length supplied would be capable of supporting 1.5 walls of brick and half a roof load. So I'm going for a 3m catnic box lintel.

 

[^woody^]

You would normally build both leafs off the external scaffold. There is no need to put the joists in or build from the inside, and the joists can be put in later off hangers if need be.

 

[chappers]

^^^That would be my preferred option every time, get the bricky to build the hangers in for you as he goes

 

[needmorstuff]

i'll have a word with him.. he knows his trade so maybe its his quirk. I am having scaffolding on outside..

If he decides he's working off scaff and can put joist hangers in for me as he goes - what lintel etc. would you guys suggest for a 2.7m opening when i do breakthrough? a normal cavity lintel through both course? an rsj? or 2 box lintels.. 1 for each course?

 

[needmorstuff]

another question.. the outside is going ahead using a 3000mm - 215x100mm keystone lintel. Inside... can I use the same thing and rest joists on it? or do you have to us rsj to rest joists on?

 

[chappers]

Any of the above, but an RSJ or box lintel would probably involve disturbing less brickwork. your BCO seems quite clued up and flexible so I would go with the box lintel catnic or IG technical help would spec one for you.

 

[needmorstuff]

i guess you're answering my previous question.. its moved on now (or so i thought) in that I am planning on using the box lintel on the exterior which is fine. Now I am unsure that a box lintel can have floor joists resting directly on it...

 

[chappers]

Most should be fine, but best to check with Keystone as to whether yours is suitable. To be honest I'm not sure which ones or under what conditions they are suitable. But I have seen drawings specifically saying that the joists shouldn't rest direct on the lintel.
However you may want to consider a steel as that way you can notch your joists into the steel to give you a flush ceiling finish below

 

[needmorstuff]

ah I see what you mean now.. the joist goes into the "c" section of the steel.. I like your style. That sounds like a tricky install though.

 

[needmorstuff]

I spoke to the bricky this morning (who has blobbed for the rest of the week - no another job) and he said he needs either the floor in or scaffolding on the inside to work off. Said something about bricks not being same height or something...