Removing entire ex-outside wall for new extension

[untrepid]

Howdy,

I've an extension coming along as pictured, and I'm always looking for more space, more for an en-suite, more for storage... and coupled with the fact that we're having the left side of the downstairs wall removed to have a huge kitchen / diner I'm taking one small thought to another and now wondering if there's a good reason we couldn't remove ALL the visible ex-exterior brickwork visible in the pictures?

The outside skin is only holding itself up, right? So why go installing a full on RSJ in the kitchen ceiling etc, when we could just remove the outside wall it'd be supporting anyway?

This still sounds mad to me, but I can't work out why. I know that the gable end wall on our new extension isn't load bearing... it doesn't even exist yet, despite the roof being up, so presumably the same goes for the existing wall?

Given there is a 6inch joist already sitting up against the brickwork, can that be used to just support the "old" gable end roof? bolt a single leaf lintel to that? Is that how it works? Some sort of bracket fixed to the joist, and resting on the remaining internal half of the brick wall? Even then it's going to have an access hole removed from it to allow access to the new loft space, again making it lighter and lighter, so I only need to support, what, 1.5m of gable roof on each side.

Rather than this seeming like a huge thing, it feels like it'd actually make the overall process simpler and simpler??

 

[Newboy]

Apart from your load-bearing questions.

Is that an active boiler flue in your second photo?

Not a good idea having POCs pumping into an enclosed space.

 

[untrepid]

Apart from your load-bearing questions.

Is that an active boiler flue in your second photo?

Not a good idea having POCs pumping into an enclosed space.

You might notice the dining room is pretty well ventilated still

 

[tony1851]

Is your existing roof a truss roof, then? If that's the case, it won't be supporting any load from the roof.
But that does not mean that the wall is non-structural - it may be providing lateral stability to the house as a whole.

 

[untrepid]

Is your existing roof a truss roof, then? If that's the case, it won't be supporting any load from the roof.
But that does not mean that the wall is non-structural - it may be providing lateral stability to the house as a whole.

I'm not sure if there's another type of roof it could be, but it has front to back beams just like the new roof does. Whilst being 50 years older, and pretty sloppily made, it looks like it's the same type.

OK, hadn't thought of lateral stability... I'll certainly be getting a structural engineer involved, but I'd like to think that as it's a solid conventional ex-council semi, that shouldn't be an issue.

 

[^woody^]

I'm sure that walls of certain heights need to be certain thicknesses so that they don't get pushed or blown over.

 

[Ian H]

Some of our neighbours removed the outer skin on the upstairs bit only when they had a double extension.

 

[untrepid]

I'm sure that walls of certain heights need to be certain thicknesses so that they don't get pushed or blown over.

But we're making it an internal wall. If has a cavity wall extending out to the side of the house now, gripping onto it. And there's still a metre of wall still external on the front, and half a metre on the back. I'm tempted to think the lateral strength thing is all just in theory, however it's legally binding theory, so be it.

 

[untrepid]

Some of our neighbours removed the outer skin on the upstairs bit only when they had a double extension.

Well we were always knocking through about 40% of the downstairs wall... then there's the new doorway upstairs...

 

[^woody^]

But we're making it an internal wall. If has a cavity wall extending out to the side of the house now, gripping onto it. And there's still a metre of wall still external on the front, and half a metre on the back. I'm tempted to think the lateral strength thing is all just in theory, however it's legally binding theory, so be it.

A wall is a wall internal or external.

Walls supporting a load are liable to buckle unless they are of a certain thickness, or are otherwise restrained. Pitched roof loading particularly.

It's not impossible to do, very common on unloaded gable walls, but front and rear walls need more consideration, that's all.

 

[stuart45]

I'm sure that walls of certain heights need to be certain thicknesses so that they don't get pushed or blown over.

As in the slenderness ratio of brickwork.

 

[tony1851]

I'm tempted to think the lateral strength thing is all just in theory,

That's the problem; your scheme may well be fine in practice, but the inspector might not be interested in that and might ask for figures to prove it - that's where the boring theory comes in.