Padstone for Bifold Steel beam?

[Tyrone Thompson]

Hi

I have a single storey extension going in with a 4m long bifold to the garden, it is likely that due to this span we would be installing this steel with welded plate as you’ve shown in your detail drawing. My question is:

Where this steel is supported at either side of the bifold, will the padstone simply be on the inner leaf? As the welded late is there to support the outer leaf of bricks and is not relying on the external bricks below as a load wall?

hope anyone can understand and give me advice. Heres a sketch I’ve done if it helps, it’s a detail of the steel at the supporting wall at either side of the bifold.

 

[John D v2.0]

This is a key part of the structural engineers work to specify the structural elements in enough detail for them to be built safely. We couldn't guess as we don't have the calculations and most of us are not qualified SEs.
For what it's worth, yes the outer leaf will be taking some load.
Also, watch out for thermal bridging with that steel plate crossing the cavity.

 

[Tyrone Thompson]

This is a key part of the structural engineers work to specify the structural elements in enough detail for them to be built safely. We couldn't guess as we don't have the calculations and most of us are not qualified SEs.
For what it's worth, yes the outer leaf will be taking some load.
Also, watch out for thermal bridging with that steel plate crossing the cavity.

if this is the case how would you overcome the thermal bridging, I doubt insulation back plasterboard would sort it?

 

[John D v2.0]

You overcome by making sure the vcl is in the right place and the u value of every part of the envelope is better than the limiting u value for that surface.
That would be for the designer to work out as for these kind of doors there probably isn't really a standard buildup.
I believe a common solution for standard UC sections is to fill the flanges with celotex and stick a strip along the bottom but either way the designer will tell you.