Glass BLOCKS

[Patti J]

I live in a 1920s house converted in 1954 into four flats only two of which share a communal staircase/fire exit. The fire assessment seems to suggest that the glass blocks that form the entrance wall of my flat cannot be proved to be fire resistant and so might have to be replaced. The blocks are hollow glass 4" deep and fire resistance was specified in the plans of 1954. The fire assessment report does suggest risk must be balanced against costs in a case like this - we will have interlinked smoke alarms and an emergency exit .HOWEVER we have to provide proof that these were fire resistant and tested, but of course there was no actual fire rating then! How can we do that if we don't know the manufacturer. They have been in place since 1954. Noone will give advice on this, and the fire brigade say it should be ok but won't put that in writing. As there are only two actual floors and two people sharing this exit... can we argue against this judgement. It will cost a great deal to replace like for like, but without glass we have no borrowed light and it seems excessive

[AnthonyB]

I had this issue at a more modern (80's) flat build - research is such that a standard 4" solid glass block is usually acceptable for 45 minutes fire resistance, which as the protection for a small full evacuation block would only need to be 30 mins makes them sufficient.

https://glassblockblogger.com/2015/09/03/glass-blocks-and-fire-safety-codes/

If you needed a greater level of fire resistance there would be a traceability issue as in these cases the blocks are specially made to have greater FR but that's not needed here.