On Thursday, 15 February 2018 13:35:57 UTC, Andrew wrote:

Standard fitment in all new houses. Much stiffer and stronger
so less of those creaky chipboard floors that 70's houses
suffer from.

The 22mm chipboard or t&g plywood flooring is glued on all
four sides and also glued onto the top section of the beam.


Metal web joints. Thanks all for that.

So if most (all?) residential new builds use MWJ (as known to its friends) as a base for ceiling plasterboard and floor ply, can they be used for loft extensions where they are fixed to the walls slightly above existing ceiling joists? The lightness, and sufficient (?) strength in comparison to "steels" would in my uninformed position, make MWJ the ideal base for the floor in a loft extension. Or do they have shortcomings that prohibit their use in loft extensions?

Thanks.