Plywood boards in riser cupboard

[Maiza]

Hi I wonder if someone can help.

We have a riser cupboard which is a solid brick shaft running through all storeys within the building. Necessary fire stopping has been done however part of the riser is cladded with plywood, I understand that this area should provide 30mins of fire resistance.

Is it ok to have it lined with Plywood with the solid brick wall being in place behind this?

Thanks for your help

[Tom Sutton]

There is no problem in using flammable material in the inside of a protected shaft, in most situation there will be, however if they are ignited  then any fire should not be able to pass to the outside of the shaft and in this situation the brick wall will achieve that.