Fitting WC Pan

[stevedo]

I have a bit of a challenge in my en-suite that is causing me some headaches in working out what to do.

The floor is not square to the wall (no surprise there really) but the margin of error is quite significant. The joists run parallel to the wall. The problem is that there is a "drop" from the joist nearest the wall to the 2nd joist (approx 19") of about 1/2". I know this because I have taken up most of the chipboard floor. I can't remove all of the floor because the chipboard runs under walls between 2 rooms.

The options I see are somehow level the top of the joist nearest the wall with joist 2. The problem is that if I plane the 1/2" needed off of the top it will be weakened and there will be a problem getting the new floor level with whats left of the existing floor.

The 2nd option would be to set the WC pan in cement and make it level in the same way that you would with a shower tray. My concern is that it might not be stable enough, may lead to the pan cracking or would be an effective method of levelling?

The reason I need to fit the pan so accurately is that it comes with some ceramic "infills" that fit between the bottom of the pan and the wall where you would normally just have a gap and be able to the waste pipe etc.

Apologies for this being a bit long winded but hope it makes sense.

What would you do?

Thanks
Steve

 

[brumylad]

In these days of routers, you could use noggins between the joists to provide good support for the board under the pan. Then as long as the board is 3/4 " or thicker cut into the board that sits under the wc pan so as to create a level "seat" for the pan.

You could build up the "lower" joists in the room and accept a step at some point,

or build them all up, (shorten the door of the room if it opens into the room) and have a threshold.

Cut the chip board overlapping into your room where they cross a joist and widen the joist by attaching a batten so the same joist can support the end of another length of board. You could accept a step between new board and old, or cover old board with 1/2" thick mdf (green coloured) stuff)

 

[bathjobby]

Had the same problem. Used self leveling compound (for wooden floors) to level the floor. Worked a treat and easy as pie.

 

[stevedo]

Thanks guys for the ideas. I'll have a think and see what the best solution is.

One further question. Would it be OK to use self levelling compound on chipboard, I'm using the green moisture resistent stuff.

Thanks
Steve

 

[bathjobby]

I used it on chipboard, but you have to ensure you get the stuff specifically for wooden floors as most are for concrete.

 

[ChrisR]

How thick can you use that stuff?

 

[bathjobby]

Threw the instruction away as they were on the side of the container. But I used it to fill a 1/2" drop over around 2' all down one side of the room, so obviously at its thickest it is 1/2". Usual common sense preparation on floor beforehand though i.e. If your chipboard is only nailed down, take the time to screw it before you cover it and always prime with a PVA solution of 1 part PVA 4 parts water. Did mine 1 year ago and laid ceramic tiles ontop (with adhesive specifically for wooden floors, so some of that was also on the leveling compound too) and the floor has been perfect this last year. Had to take a tile up and replace a few days after laying and interesting to find that the adhesive was still flexible after having dried. It was supposed to be, but nice to see it was as you don't always get the results your expecting.