# Forum Home Renovation Waterproofing  Waterproofing Scyon / Villaboard / Hobless Shower

## ATMNut

Hello all,
OK, I have layed the scyon flooring and sealed the t&g joints and screw heads with Hardies sealant, as well as fixing the two puddle flanges to the floor (s/s screws and Hardies sealant).  I am planning a hobless shower with a sliding (frameless) glass door. The plumbing / insulation / villaboard still needs to be done, but I have started thinking about the waterproofing.  Even though I have done a lot of research, there are a few questions I need resolved in order to proceed.  So far I have contacted a couple of highly recommended tilers who have come out to give me a quote on waterproofing and tiling. I expected that they would be completely on board with everything concerning bond breakers, but they both had the same basic approach - 11fc filleting in the joints and waterproofing straight over that; never had leaks, etc. So ... I'm now thinking that I may do the waterproofing myself .. not sure, but based on these responses and also some other questions :  
1. I have read that some polyurethane sealants may act as bond breakers, but I didn't think that 11fc was one of them (and can't actually find any others that are rated as such)?  My understanding is that silicone is the best bond breaker (in both liquid and adhesive tapes).  
2. Do I need to have bond breakers over the scyon t&g joints (which I have sealed with James Hardies sealant). If so, would I just smear a 12mm wide strip of Davco K5 over them (and over the Hardie sealant which is somewhat smeared from the joints) for instance? Same around the puddle flanges? and vanity/toilet pipe flanges?  
3. I believe that I can just use some silicone bond breaker to fill the scyon/villaboard & villaboard wall corners and extend to a thin fillet on the outside of the villaboard edges?  
4. I am planning to have two 40x40 aluminium angles sikaflexed to the scyon, one at the entrance and one at the hobless shower (see blue lines in diagram).  The floor tiles will drop down in the shower section 10mm below the rest of the floor to stop water washing out under the sliding door section. I plan on waterproofing the whole floor (and 100mm up wall) as well as the 3 shower walls up to 2m. The fixed part of the glass shower screen will be siliconed to the top of the waterstop, and the sliding door (rolling on a track on the inside of the fixed screen) will thus hang over the lowered shower floor. Any potential problems with this approach, or is there a better approach?

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## METRIX

You are correct, 11FC is not a bondbreaker, it is an adhesive / sealant, probably one of the best at that, you use 11FC between villaboards sheets, smear it over any sheet penetrations and anywhere else you want to seal. 
11FC is not used as a bondbreaker because it's properties are to adhere to other surfaces, even when cured it will adhere to the membrane being applied, so if movement occurs the membrane can tear at the critical movement joint because it's been glued to the supposed bondbreaker, so it's basically useless as a bondbreaker. 
This is stated in the Sika data sheets, your tilers who are using it need to read the datasheets for the products, this way they ensure the correct product is being used for the job. https://www.nzspecialisedcoatings.co...FC-Sealant.pdf 
A bond breakers job is to permanently break the adhesion between two joints, such as floor to wall and wall to wall junctions, the only way you can achieve this is to use a neutral cure "silicon", such as this parfix one, it's cheap and perfect for the job. https://www.bunnings.com.au/parfix-3...E&gclsrc=aw.ds 
The reason you use neutral cure is because the acidic cure silicon's can affect the membrane and cause it to fail, and silicon is used because once cured nothing will stick to it, so once the membrane cures, it will let go of the silicon if movement occurs. 
Also make sure you have recessed the puddle flanges "below" the surface of the Scyon, these need to be at the lowest part of the floor, the flange of the puddle flange cannot sit proud of the flooring surface, this is usually achieved with a cup grinding wheel.
I use these to recess the flanges as they give a nice consistent grinding level change, my one has a vac attachment on it, as cup grinding creates a massive amount of dust. 
Scyon contains silicate which is basically the same as Asbestos and can cause silicosis if breathed in when it's ground up and you are unlucky.  https://www.silicosissupport.org.au

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## ATMNut

Thanks Metrix, yeah I wasn't wanting to do everything myself but it looks like I will end up doing the waterproofing. I want to adhere to best practice rather than just accept practical experience; it's 10-15 yrs down the track that things may start to fail and I suppose people just accept it at that stage and wouldn't go looking for the original tiler/waterproofer (even if they were still the original owners). The guys do immaculate tiling from what I can see so it just came as a surprise (it was suggested that I read too much...).  I'm thinking of using Davco products, although I may look at some of the GripSet patches for the floor flanges and tap penetrations.  
My plumber recessed the holes for the puddle flanges (he used an angle grinder horizontally with a diamond cutting blade and basically cut the rebate out from the middle of the hole). I've set the puddle flanges in using 4 s/s screws countersunk in each flange after setting them with a generous amount of Hardies Joint sealant. The flanges ended up flush with the scyon flooring and feel rock solid. I had already made sure that the floor joists as a whole were flat and level to a tolerance of 1mm. In fact I found one of the scyon sheets has a slight bow in it (why is nothing ever perfect in this world?  :Wink:  ) which raises the floor 2mm down the centre of the sheet; by good fortune this line is close to the shower waterstop which means that screed water will tend to flow towards to the shower puddle flange or the general floor waste. FYI - the original joist levels were about 10mm low in one corner of the room  :Shock: , and were not flat / in line, but thankfully they are structurally sound.

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## METRIX

I have seen many tilers offer to do the waterproofing as they think it's an easy way to get another $500+ from you, as an end user you trust they know what they are doing because they are a tiler, right ?, wrong. 
Problem with most of them is they are not qualified to offer this service, and end up doing things wrong because they haven't done the training that shows them what products to and not to use and how to apply the products to guarantee no issues in a few years, which is why your ones use FC11 as a bond breaker because they don't know the difference, funny thing is FC11 is three times the price of a NC Silicon. 
The issue you have with doing the waterproofing, is if you use tilers, and they inevitably damage the waterproofing and either don't realise, or don't tell you (I have had experience with the later) then something can go wrong, and how are you going to prove who's fault it was ? 
For my own jobs I am qualified to do the waterproofing, I also do the tiling because I'm very anal about the finished product, and placement of tiles in relation to drains etc.
For any client jobs, I use a crew who are licensed water proofers and immaculate tilers. 
The reason I use others to do clients jobs, is if something goes wrong (which it hasn't) then you have one port of call, as they did the entire job, not worth the headache having two separate trades if the crap hits the fan, after all the client is paying for the job to be done. 
The gripset waterproofing detail products are great, I don't like their membranes and prefer Davco (Sika) and Crommelin and, the Gripset silicon bondbreaker tapes, and pre made corners are all I use, and have been using them for 10 years without a failure, I will continue to use them as you get a guaranteed result.

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## ATMNut

All good points; I did also have concerns regarding allocation of responsibility w.r.t. failure of waterproofing if I do it and they damage it, etc.  I did ask one of them whether he could certify his own waterproofing and the response was "yes, no problem getting it certified" - but whether that means he would personally certify the work I'm now not so sure ...  Of course, as a layperson it can be quite difficult to argue with guys having 20+ years professional experience and a (claimed) history of successful jobs (with no leaks). I would be interested if you had anyone you could recommend in my area?  I'm waiting on a quote from the second guy (overdue) - I may have discouraged him with my "interrogation" ...

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