Removal of part of outer leaf of bungalow wall...

[MeldrewsMate]

Dear All, I will shortly begin replacing the kitchen in my dad's bungalow. The kitchen (built around 1990) is an extension to the main house, accessed through what used to be the back door. It would be very useful to remove the old outer leaf of the wall to gain about 150mm on the 'new' kitchen length. Whilst I have inspected and found that the inner leaf only supports the roof, this wall is tied to the outer leaf and surely this provides stability to the inner load bearing wall (which is constructed of lightweight concrete/cinder/ash blocks...perhaps these are referred to as 7 Newton blocks nowadays, though I am not certain).

A search of this forum came up with some comments of interest:-

What will then stabilise the 100mm inner wall which is holding up the roof and floor?
and..
Building regs require a minimum thickness for a single skin wall of 140mm up to 2.4m.

A sketch may illustrate my proposal better...

...any comments or recommendations?

MM

 

[martygturner]

Why not just remove the wall up tp the kitchen extension walls. Prop the inside joists and fit a new precast lintel to support the roof joists. . Lets face it 150mm only matters in a porn film

 

[jono_h]

We did this when we built our extension - we lost the original outer leaf to make the bedroom wider.

We had to work with the Architect to come up with some modifications to the roof structure, but it wasn’t anything major. And certainly no mention of a minimum wall thickness of 140mm from Archtitect or Building Control.

 

[^woody^]

It's not the downward load, but the sideways load from the rafters trying to push the wall out. If that is dealt with and resisted by the extension roof, all is well.

The left and right wall in that image will need to be tied to the main bungalow inter leaf.

 

[MeldrewsMate]

...Lets face it 150mm only matters in a porn film...

If you've managed to get a 300 wide kitchen unit into a 200 mm gap then I'm all ears.

Thank you for the other replies and, yes, the outer leaf that remains will have extra ties to the inner leaf.
The extension's roof is flat, and has recently been re-felted (yes, old fashioned felt!), it appears not have been insulated so the kitchen ceiling will be pulled down for both insulation purposes and for lighting wiring changes. Once the ceiling is down I can better inspect the lateral support for the roof in that corner.