How to Close a New Build Cavity - Bi-Fold Doors

[Markyb250]

Hi all,

I hope you are well. I am looking for some advice on our extension and how to close our cavity floor to install a bi-fold door.

Currently we have a 2.05m high by 2.0m wide area for the bi-folds. On the external wall is a layer of stone directly on the blocks which has a DPC and is 100mm higher than the internal wall which is just the blocks currently.

For the walls I assume I just use a 100mm cavity closure but I am not 100% on how to finish off the close for the floor.

Do I build up the internal wall with 100mm block work to be level with the external stone? If so, how do I fill the 100mm cavity and close it off?

The internal floor will have 100mm celotex and 75mm screed. So could you just fill the cavity gap and not build the internal block work up by and install just screed over the area install?

Thanks in advance.

 

[23vc]

Bring the slab, insulation and screed out to meet the outer skin under the doorway

 

[Markyb250]

Thank

Bring the slab, insulation and screed out to meet the outer skin under the doorway

Thanks 23vc. Currently the slab is around 100mm below the inner blocks, so it would be 100mm Celotex and 75mm screed with underfloor in there. Could a solution be to add another 100mm in blocks to align inner and outer and fill the cavity with concrete around the door area? I assume this is preferred as screed alone would just crack in the 100mm cavity?

 

[23vc]

I’d knock out the inner skin blocks so you’ve got room for insulation and screed up to the outer skin