How to reboard original bathtub drain hole?

[WSR]

Hello All,

We are having a new bathtub installed with a centre drain.

We know the large hole from the original bathtub, (which had an end-drain), must be re-boarded prior to tiling but we're unsure what to do about the 4 corners around the new drain.

Does this need to be filled or sealed, and if so, how?

Thanks in advance

.

[JacobZ]

Hi @WSR,

Can you advise how thick the floorboards are? The choice of material would be determined by the thickness of these timbers.
 

My suggestion would be to cut out the section that separates the two holes to create one uniform rectangular hole. I have drawn the outline below.

This should give you access to 3 floor joists to attach a new piece of flooring material to.

Once this rectangular piece is in place, a round hole can be cut using a hole saw, jigsaw or angle grinder, depending on the material chosen to fill the hole. This hole should be large enough to accommodate the drain pipe.

Once you've advised the thickness of the floorboards, I'd be happy to recommend a suitable material to fill this hole with.

Let me know what you think and if you have any further questions.

Jacob

[WSR]

Thanks Jacob, the board is 19mm hardwood.

[JacobZ]

Hi @WSR,

Some STRUCTAflor General Purpose YellowTongue would be perfect to fill the gap.

You would then need to put a suitable fibre cement material on top before waterproofing. This will give you a sturdy repair that is capable of being waterproofed to modern standards.

Let me know if you have any further questions.

Jacob

[WSR]

Thanks Jacob, job's now all done.

Your advice throughout this bathroom reno has been invaluable and very much appreciated.

Thanks so much.

[MitchellMc]

That's great to hear @WSR. Feel free to share some images of the finished job. I trust they'll assist any of our members who come across your discussion and have a similar issue.

Mitchell