Grateful for some advice if poss please...
I have a floor threshold height issue which means i'd like to use 11mm OSB to replace existing 18mm floor boards. I know, I know! 11mm is not thick enough BUT.. I intend to overboard it with 6mm no more ply. I will also be adding nuggins in the floor joist where ever there's an OSB board join. Joist are at 430 ctrs.
So I know min 18mm osb/chipboard/ply is recommended but REALLY, would the combination of 11mm OSB AND 6mm NMP not be ok?
My logic is that the 6mm element of the NMP is actually stronger than 7mm OSB (difference between 6 and 18mm osb). So surely the combined structural strength of 11OSB + 6NMP would amount to more than 18mm OSB, which is considered ok.
Or am I just plain crazy!