Single skin build

[PhiLyn]

Dearest experts,

We're undergoing a garage conversion at home and the boss lady would like a 5m bifold door in one of the existing walls of an old oil tank room (lean to on the main garage)
The wall is single skin, 4 inch concrete block construction holding up a flat fibreglass roof (which will be replaced with the same but beefed up a bit). The original plan (agreed with my lovely building inspector) is to insulated externally and timber clad over.
My concerns are;
1) that's quite a span for such a large opening. A heavy I or C section steel can do it but it seems a bit.... wobbly to me
2) the windows would be attached to the inner skin rather than the normal outer skin. Is this going to look weird or more importantly work with cold bridging etc?

Thanks in advance

 

[John D v2.0]

It's fine with the windows, just use brackets to hang them in line with the insulation.
You can laterally restrain the beam if specified.

 

[PhiLyn]

Thanks John, never thought of the window bracket option. Must have killed that brain cell...
Lateral restraint to the beam will be provided by the roof joists tying everything to the existing garage wall right? Stops it toppling over. Or am I misunderstanding this bit?

 

[John D v2.0]

Yes as long as the joists are attached properly it would work. Not sure what the definition of properly is though, someone else's will be along to help I'm sure!

 

[John D v2.0]

Failing that, you can try buying a propitiatory lintel eg catnic and call their tech support line for advice

 

[PhiLyn]

Did the Catnic thing but they didn't have a solution for a single block wall with that span.

 

[PhiLyn]

I recon a few screws through the joists into a wall plate would be the way to attach but will be happy to be corrected

 

[John D v2.0]

Consider some metal strapping to hold the joists and wall plate to the blockwork, maybe the same at the end with the steel.