Builder filled outside of steel with celotex, is this right?

[steveinoz01]

Hi all

I think I know the answer but… my builder has filled the steel over the bifold opening with celotex. This is on the outside. I assume he has done the same on the inside but this has been plaster-boarded. It is being rendered so won’t be seen but shouldn’t it be brick or block?

See picture.

Thanks

 

[John D v2.0]

Yeah really you want it insulated on the outside as much as possible, steel is an awful thermal bridge and you can end up with lots of problems if it's cold on the inside.

 

[RandomGrinch]

I may be wrong, but I don't think you need to be worried that it won't be brick or block.
Most retrofit external insulation uses a reinforcing mesh fixed over rigid insulation blocks, before being rendered.

 

[Notch7]

It just needs a bit of expanded mesh

 

[steveinoz01]

Thanks everyone, that has set my mind at rest.

Much appreciated.

 

[Dodgyrog]

Similar situation here, although we did block ours up - but used mortar bed reinforcement because a long single course of blocks it not the strongest of structures, hence your builders opting for insulation approach instead.

 

[Deleted member 292770]

the joist should be sat on a concrete pad.