Chipboard repair between two joists

[walmslei]

Hi

Just effectively checking what I've done is okay - We had a rewire and it necessitated taking a line of chipboard out of the room between joists (at 12" centres) down the very edge of an upstairs room - There is a joist tight to the wall and another set into the room, and then the chipboard flooring runs across the rest of the room with the panel 'half lapping' on this joist (screwed down).

I didn't think anything of it - As its effectively a butt joint I bought some 18mm chipboard loft panels from B&Q (on the site it said P4 graded) and cut them down to 13" or so sections, screwed to joist half holding the other sheet and then to the joist on the other side by the wall.

It seems sturdy enough (I weight 16 stone and can jump on it with full force, heh) but someone told me I cannot use loft panels as they aren't graded for habitable use - I figured if they were P4 they were fine for load bearing providing they didn't get wet?

http://www.diy.com/departments/chipboard-loft-panel-pack-of-3-l122m-w325mm-t18mm/61765_BQ.prd

Am I pulling these up? I really don't want to redo the whole room, so if I am then I guess I'm chopping up little bits of 18mm floorboard to fill the gap down the edge of the room.

Ian

 

[stevethejoiner]

The chipboard you have used is correct for interior domestic flooring for any dry rooms, not just lofts. It cannot/should not be used in bathrooms and kitchens etc. Its load bearing properties are fine for domestic use, as long as you do not have butt joints between joists that is, cut board joints need support. So it looks like you have done it right.

 

[walmslei]

No butt joints between joists - I figured P4 18mm Chipboard was 18mm chipboard... its was only after that someone told me you couldn't use the small sheets in habitable rooms. Its basically gone into a small 2.2m x 2.2m bed(box)room and each end sits on a joist and is fixed - From my side I couldn't see a problem with it unless either a) Convention dictates that you get more strength by spanning more than two joists (doesn't seem to make a lot of sense to me, you see quite a lot of single span floorboard hatches in houses where plumbers/sparkies have cut the floor to get to pipes OR b) that you get different strengths of chipboard - I guess thats possible, maybe.

Anyrate thanks for the reply, I intend to hardboard over it before carpets go in as the old floor (big chipboard sheets) has a few knackered tongue/grooves where people have dragged it up over the years and broken it (again not between joists, running the opposite way).