I'm redoing my bathroom and have chipboard down. 

 

I want to reroute existing Mains water feeds for the basin and it would involve removing enough to get to where it comes off existing 22MM pipe shown. 

 

Joist and joint line for one 600mm wide board is in blue.

 

What can I do to replace this section of floorboard based on it being under the stud at the moment? 

 

Also, I've gone through the existing board in another section with the SDS ripping tiles up, is this repairable with just cutting out and noggin it etc?

 

 

 

Cut along the red line, to leave the chipboard under the stud wall. 
 

Then put a piece of wood (18mm plywood or similar) under that existing flooring, wide enough to be 75mm under existing and 75mm on show, and screw / glue it by fixing down through the chipboard into the plywood to form a connecting ‘tongue’ of plywood. 
 

Then your new flooring will sit on that, which you then glue and screw down into, and job done. 

8 hours ago, Nickfromwales said:

 

Cut along the red line, to leave to chipboard under the stud wall. 
 

Then put a piece of wood (18mm plywood or similar) under that existing flooring, wide enough to be 75mm under existing and 75mm on show, and screw / glue it by fixing down through the chipboard into the plywood to form a connecting ‘tongue’ of plywood. 
 

Then your new flooring will sit on that, which you then glue and screw, and job done. 

Thanks Nick, I thought I'd be looking at doing that sort of arrangement. Would you take the full board out or do the same along the opposite side? 

 

 

1 hour ago, deasonuk said:

Thanks Nick, I thought I'd be looking at doing that sort of arrangement. Would you take the full board out or do the same along the opposite side? 

 

 

Same if the existing boards are ok. 
 

Maybe use the opportunity to put some fresh acoustic insulation in there. 
 

For my SiL’s house I put plywood inside the metal webs of the MF tracks to beef up the walls before plaster boarding.

 

Made the wall much stronger. 

That's another challenge I need to work out the stud situation. Posting about stud wall in another thread for input  

 

 

I have a good reason to not trust the plumbing in my house - as a result both bathrooms when they were refurbed have had the chipboard floors lifted.

 

Similar arrangement where the internal walls have been built on top of the chipboard floors 

 

So my advice is similar to @Nickfromwales Get it up where you can, work out where the floor joists are and then either under-board with ply or screw 2 x 2 to the existing joist to give support to the new floor whichever works best for the situation

 

Deal with all the plumbing alterations 

 

Take a picture of the floor with everything finished

 

Then before you put the floor down again put some "sound absorbant batts" between the joists (especially if bathrooms are above living areas) 

 

Lay the floor down sheet at a time and mark any areas where pipe work or wiring runs pass under (if you forget to do this that picture comes in handy) 

 

Oh and glue and screw the floor down avoiding any pipe runs on the floor (use decent flooring screws that don't jack the boards off the joist (or drive them in, out and then in again for a tight fit and no jacking)