Concrete lintel or RSJ Beam, advice needed - bifold doors.

[bunkotungus]

I'm fitting 3.1m bifold doors into a solid brick external wall.
There's only going to be a few courses of brick above the door and a flat rubber roof, so not much weight.
What type of lintel or beam would be best for this? There's lots of different types of RSJ beams out there and I don't know which one is best for an external solid brick wall.
Thanks.

 

[freddiemercurystwin]

Is your bifold floor supported or hung off the lintel? How thick is the wall? 225mm?

 

[RonnyRaygun]

A beam with a bottom plate to carry the outer brickwork would be suitable. If the wall is rendered then you could just stick in a wider beam and render to expanded metal lath between the beam flanges.
You might get a precast concrete lintel to work depending on the loads above.

 

[bunkotungus]

Is your bifold floor supported or hung off the lintel? How thick is the wall? 225mm?

Floor supported, yep 225mm

A beam with a bottom plate to carry the outer brickwork would be suitable. If the wall is rendered then you could just stick in a wider beam and render to expanded metal lath between the beam flanges.
You might get a precast concrete lintel to work depending on the loads above.

The wall isn't rendered. A beam like the one in this pic? So the width of the welded plate would be 225mm which would sit on the bricks, but how would the bricklayer lay bricks on top of this? by building up the outer brickwork on top of the plate? Thanks.

 

[RonnyRaygun]

Exactly that yes! Obviously the beam needs to be narrow enough that you can get a course of brickwork in front of it.

 

[^woody^]

Standard lintels are available. Less thermal bridging.

 

[bunkotungus]

Standard lintels are available. Less thermal bridging.

I can't find any reinforced concrete lintels long enough

 

[^woody^]

Steel lintel!

Concrete lintel will be massive and impractical.

 

[tony1851]

@op Google 'Catnic lintels'.

 

[RonnyRaygun]

Steel lintel!

Concrete lintel will be massive and impractical.

Plus you'd not be able to fit the outer brick skin...

 

[bunkotungus]

Exactly that yes! Obviously the beam needs to be narrow enough that you can get a course of brickwork in front of it.

Standard lintels are available. Less thermal bridging.

@op Google 'Catnic lintels'.

would this catnic cn81c lintel do it? see picture. thanks guys.

 

[George_engineer]

Yes that would. It's a lighter weight / more efficient version of the beam with a plate welded on the bottom.

Although how have you ended up with a solid wall for a bi-fold door? Usually bi-folds would be put in a new build part so would be a cavity wall.

 

[jks7492]

Although how have you ended up with a solid wall for a bi-fold door? Usually bi-folds would be put in a new build part so would be a cavity wall.

Retrofitting in an older house built before cavity walls were the norm?
Bi-folds aren’t exclusively for new build houses…

 

[George_engineer]

Retrofitting in an older house built before cavity walls were the norm?
Bi-folds aren’t exclusively for new build houses…

Sure, sorry there was a bit more thinking behind the reply that I didn't write.

An opening over 3m in width isn't allowed in the normal Part A of the building regulations so to get an opening of that size they'd either already need an engineer to help (who could have specced a lintel) , or it'd have been designed new and so wouldn't be solid wall.

 

[phatboy]

or it'd have been designed new and so wouldn't be solid wall.

We are building an extension, and going with solid walls, and external insulation... more new builds are going this way it seems.

For us it was better for self-build, as insulating the outside is a more DIY task than cavity insulation.