Studwall built on floorboards

[mibazza]

My bedroom stud wall is built onto the overhang of the floorboards after the joist below. So my joist runs parallel to the stud wall, but the stud wall is built about 100mm after the joist toward the stone outside wall so that the stud wall is just sitting on the ends of the floorboard which extend past the joist toward the outside wall. Does that make sense? I want to remove some floorboards for new radiator piping but I'm worried that if I cut the floorboards along a joist near to that wall then all the wall is being supported by is the short pieces of floorboard left between my cut (parallel to the joists) and the floorboard ends over which the stud wall is built. Can I just remove the entire stud wall, lift the floorboards do the work, then re-build the stud wall 100mm further into the room so its over the joist? My issue then with that is that the stud wall sits parallel over the joist in the roof so if I move 100mm to sit the wall on the floor joint I'll then be 100mm out from the roof joist. I don't want to take the roof down to double the roof joist and I also have a structural steel beam attached perpindicular to the roof joist which runs the length of the house (flat roof dormer). I'll try and get some photos to clear up what I'm trying to explain.

 

[mibazza]

You can see the stud wall built over the floorboards in the photos below, in one of them you can see the joist below the foot plate clearly not over the joist.

 

[mikeey84]

Do you need to cut all the floor boards or could you cut every 3rd one?

 

[mibazza]

The pipes will be running perpemdicular to the joists so I have to take up a fair few, some of them are a bit soft aswell, looks like they've had some water damage at some point over the years, I'd like to replace them all but all the walls are nailed to them.

 

[Bilabong007]

Could you run the pipes above the floor but behind the wall?

 

[mibazza]

Could you run the pipes above the floor but behind the wall?

Hmmm not really although that would.be good, the pipes will pass the chimney breast which is hard to the stud wall and its insulation so I wouldn't get insulation on the pipes.