Toilet room renovation

caru

Hi All, 

We wanted to do some work / renovation around the house and have decided to start with the toilet room (on the second floor). 

The plan is to 

1. Remove the tiles and toilet ourselves - Done

2. Get someone in to do the waterproofing and tiling - Already engaged a licensed renovator to do it for us

We have got a question though; while removing the floor tiles; we also removed something like a mesh / fiber layer and also the screed on the top of it (did we somehow destroy the old underlay while removing the floor tiles?)

The question is do we need to install a new backer board (like cement sheeting)? Or can we just get the guy to screed / water proof straight away? 

I have attached some pictures - we are not sure if its the sub-floor or some sort of sheeting.

I guess we would like to know what sort of work is involved so we have some basic understanding when talking to the renovator.

Thanks in advance!

MitchellMc

Welcome to the Bunnings Workshop community @caru. It's great to have you join us and many thanks for your questions.

You most likely removed the waterproofing membrane fabric and the tile adhesive. I believe you would have noticed a flat sheet product if you had broken it apart and removed it. There seem to be two trains of thought with structural flooring in wet areas. The first is that if you seal it with something like Bondcrete then you can go straight over it with a waterproofing membrane and fabric. The second is that you need to have a cement sheeting laid on top of it and that is what gets waterproofed.

What that appears to be in your picture is the Structafloor subfloor.  If you have engaged a licensed renovator to do the waterproofing for you I would simply give them a call. Ask them if they need you to purchase some cement sheeting or will they waterproof directly over the Structafloor.

Here's a step-by-step D.I.Y. article on How to waterproof your bathroom which I trust you'll find useful. You'll note in this video they are waterproofing the cement sheeting and not Structafloor.

Let me mention the very knowledgable @Brad to see if he has any advice.

Please let me know if you need further assistance or have any questions.

Mitchell