# Forum Home Renovation Waterproofing  Silicone - Villaboard - Waterproofing:  Are they all friends?

## mgt

Greetings all, 
First of all - great Forum, have read heaps and am continuing to learn the more I read (and do). 
I am in the middle of a Bathroom and Ensuite demolition and re-build (first job of this kind).  My question (this time - I have heaps) relates to Silicones and which type to use and their compatibility - as I have read some conflicting information. 
I am part way through erecting my Villaboard:  Which Silicone (or Silicone/Adhesive) should I use for the corner (wall/wall) and the floor (floor/wall) joins in the recommended 6mm gap? 
I have read many recommendations, many say use SikaFlex - but which one?, there are about 12 of them?  I used SikFlex 11FC to glue an EziLay shower tray down - would this be suitable for the Villaboard joins?  However this is Acetic Cure...... 
I believe I read somewhere that only a 'Neutral Cure' silicone should be used (can't remember if this is a requirement for the villaboard or the waterproofing membrane??) .  I can only find one Neutral Cure Silicon in Bunnings etc. (a Selley's bathroom silicon in a white bottle). 
I will probably end up using the Dunlop Waterproofing Products (Primer, Membrane - followed by Dunlop Wall and Floor Tile adhesive for the 600mm x 300mm tiles).  Do some Silicones not work with all waterproofing systems or cement sheeting?  Do I need Neutral Cure?   
Or can I rest easy and use any silicone with any waterproofing products - in that case, Which is the best? - especially given that some of my joins are a bit more than the advised 6mm (a combination of out of square walls/floors and my cutting skills) 
Thanks all for reading this long post (for a short question), I look forward to your advice. 
Cheers,
Mgt.

----------


## phild01

> Greetings all, 
> First of all - great Forum, have read heaps and am continuing to learn the more I read (and do). 
> I am in the middle of a Bathroom and Ensuite demolition and re-build (first job of this kind).  My question (this time - I have heaps) relates to Silicones and which type to use and their compatibility - as I have read some conflicting information. 
> I am part way through erecting my Villaboard:  Which Silicone (or Silicone/Adhesive) should I use for the corner (wall/wall) and the floor (floor/wall) joins in the recommended 6mm gap?  
> Most polyurethanes are suitable for this application.  Bunnings have a variety in sausages including the Sika ones. 
> I have read many recommendations, many say use SikaFlex - but which one?, there are about 12 of them?  I used SikFlex 11FC to glue an EziLay shower tray down - would this be suitable for the Villaboard joins?  However this is Acetic Cure......  It's fine. 
> I believe I read somewhere that only a 'Neutral Cure' silicone should be used (can't remember if this is a requirement for the villaboard or the waterproofing membrane??) .  I can only find one Neutral Cure Silicon in Bunnings etc. (a Selley's bathroom silicon in a white bottle).  Acetic cure is a problem where metal is involved.  It is a better silicone but usually used for glass and ceramic applications.  Bunnings do have plenty of neutral cure silicones, just look for guttering/downpipe type product. 
> I will probably end up using the Dunlop Waterproofing Products (Primer, Membrane - followed by Dunlop Wall and Floor Tile adhesive for the 600mm x 300mm tiles).  Do some Silicones not work with all waterproofing systems or cement sheeting?  Do I need Neutral Cure?   Be careful here, more to do with bond breakers and the membrane product you are using. 
> Or can I rest easy and use any silicone with any waterproofing products - in that case, Which is the best? - especially given that some of my joins are a bit more than the advised 6mm (a combination of out of square walls/floors and my cutting skills)  Still suggest a polyurethane for this unless you want silicone as a bond breaker (poly needs masking tape over the corners) .  Bunnings sell a sausage gun for about $10.  Depending on your Bunnings, the sausages are usually stocked near the trade desk away from the regular cartridge products.  Research the product info before you do your waterproofing.  Understanding all the requirements is important. 
> ...

  ..

----------


## Oldsaltoz

> Greetings all, 
> First of all - great Forum, have read heaps and am continuing to learn the more I read (and do). 
> I am in the middle of a Bathroom and Ensuite demolition and re-build (first job of this kind).  My question (this time - I have heaps) relates to Silicones and which type to use and their compatibility - as I have read some conflicting information. 
> I am part way through erecting my Villaboard:  Which Silicone (or Silicone/Adhesive) should I use for the corner (wall/wall) and the floor (floor/wall) joins in the recommended 6mm gap? 
> I have read many recommendations, many say use SikaFlex - but which one?, there are about 12 of them?  I used SikFlex 11FC to glue an EziLay shower tray down - would this be suitable for the Villaboard joins?  However this is Acetic Cure.....  Sikaflex11FC is not a silicon based sealant, Works fine for wet areas, I use it every day and never a problem. 
> The problem with silicon based sealants is that while they stick to anything, almost nothing sticks to Silicon, this can mean problems if you find you want to put anything over it, like another sealant, it will not stick. Cleaning off old Silicon needs chemicals like Acetone (not good in a confined space) and any residue at all will result in poor adhesion. I do not use Silicon at all. 
> I believe I read somewhere that only a 'Neutral Cure' silicone should be used (can't remember if this is a requirement for the villaboard or the waterproofing membrane??) .  I can only find one Neutral Cure Silicon in Bunnings etc. (a Selley's bathroom silicon in a white bottle). 
> I will probably end up using the Dunlop Waterproofing Products (Primer, Membrane - followed by Dunlop Wall and Floor Tile adhesive for the 600mm x 300mm tiles).  Do some Silicones not work with all waterproofing systems or cement sheeting?  Do I need Neutral Cure?   Sikaflex11FC will be fine. Also works fine with the backing rod and tape bond breakers around the wall to floor joints. As well as seating and sealing the puddle flange without the screws.  
> Or can I rest easy and use any silicone with any waterproofing products - in that case, Which is the best? - especially given that some of my joins are a bit more than the advised 6mm (a combination of out of square walls/floors and my cutting skills) 
> ...

  fine.Good luck and fair winds.

----------


## mgt

> ..

  Thanks for your post.    _"__Acetic cure is a problem where metal is involved"_ 
I have angled tin in the corners.  Does this mean that SikaFlex 11FC is no good for this job?  The angle tin is not there as a waterproofing mechanism - but more to hold the boards of both walls together a bit better (old house with movement) to avoid grout cracking down the track.  "_Still suggest a polyurethane for this unless you want silicone as a bond breaker (poly needs masking tape over the corners) ._"  
Not sure I am fully with you here (sorry - very new to all this).  The Sika (or silicone) I am after is purely for the villaboard joins in this application.  I will be conducting a full waterproofing membrane over the top of the lot with the "fabric" type strip down the wall corners and on the floor/wall junction as part of the waterproofing.  If I use the Sika 11FC - does that need masking tape over the corners?  What exactly do you mean by this?  
Thanks,
Mgt.

----------


## mgt

> fine.Good luck and fair winds.

  Thanks for the explanations. 
If Sika 11FC is not a Silicone - then does that mean things _wil_ stick to it?  Like the waterproof membrane I will be using?  "As well as seating and sealing the puddle flange without the screws. "
Thanks for this - it was another question I had.  I have a Plastec Puddle Flange that needs to be glued to the bottom of the EziLay shower tray.  My concern was that on the Sika FC tube it states "not suitable for all plastics" so that had me a bit worried. 
Cheers,
Mgt.

----------


## phild01

> Thanks for your post.    _"__Acetic cure is a problem where metal is involved"_ 
> I have angled tin in the corners.  Does this mean that SikaFlex 11FC is no good for this job?  The angle tin is not there as a waterproofing mechanism - but more to hold the boards of both walls together a bit better (old house with movement) to avoid grout cracking down the track.  Not sure why you feel 11FC is acetic!  It is a non-corrosive product recommended for applications of metal and moisture.  "_Still suggest a polyurethane for this unless you want silicone as a bond breaker (poly needs masking tape over the corners) ._"  
> Not sure I am fully with you here (sorry - very new to all this).  The Sika (or silicone) I am after is purely for the villaboard joins in this application.  I will be conducting a full waterproofing membrane over the top of the lot with the "fabric" type strip down the wall corners and on the floor/wall junction as part of the waterproofing.  If I use the Sika 11FC - does that need masking tape over the corners?  What exactly do you mean by this?   As I was saying, research this so you feel confident going about doing this.  Following advice is good but reading and understanding is better for such an important aspect for avoiding water damage.  The waterproofing needs bond breakers in the corners.  Some fabric incorporates a non-stick strip and some don't.  If your waterproofing sticks in areas of potential cracking, then it will fail to do it's job.  Manufacturers of waterproofing build in a small degree of flex and the bond breaker allows for this flex to occur.  Waterproofing is dead easy provided you do it right. 
> Thanks,
> Mgt.

  ...

----------


## Oldsaltoz

> Thanks for the explanations. 
> If Sika 11FC is not a Silicone - then does that mean things _wil_ stick to it?  Like the waterproof membrane I will be using? "As well as seating and sealing the puddle flange without the screws. "  Yes. 
> Thanks for this - it was another question I had.  I have a Plastec Puddle Flange that needs to be glued to the bottom of the EziLay shower tray.  My concern was that on the Sika FC tube it states "not suitable for all plastics" so that had me a bit worried. 
> Cheers,
> Mgt.

  Puddle flanges are designed to be installed into the floor, not stuck to the back of a pre-cast shower base. 
Also see: https://2ecffd01e1ab3e9383f0-07db7b9624bbdf022e3b5395236d5cf8.ssl.cf4.rackcdn.c  om/Product/d5043a22-bfd5-46eb-8ed2-88cd9801663e.pdf   Good luck and fair winds.air winds.

----------


## goldie1

> Thanks for the explanations. 
> If Sika 11FC is not a Silicone - then does that mean things _wil_ stick to it? Like the waterproof membrane I will be using?  "As well as seating and sealing the puddle flange without the screws. "
> Thanks for this - it was another question I had. I have a Plastec Puddle Flange that needs to be glued to the bottom of the EziLay shower tray. My concern was that on the Sika FC tube it states "not suitable for all plastics" so that had me a bit worried. 
> Cheers,
> Mgt.

  Yes waterproofing will stick to Sika 11FC and its ok to stick the puddle flange to the shower tray.  In the link I gave you in 
the bathroom forum http://www.renovateforum.com/f247/ez...estion-111169/  the white 
sealant you see in the pics before the green waterproofing  is Sika 11FC. 
Waterproofed joints ie wall/wall corner or wall/floor  etc require a bond breaker to prevent the waterproofing membrane  
from cracking when the joint moves. As nothing sticks to silicon it can be used as a bond breaker. ie fill the 6mm corner 
gap with silicon. The fabric tape is then stuck to the villaboard on either side of the silicon.  Then the waterproofing membrane  
 is applied to the tape bridging the corner but allowing movement.  ( this is one type of bond breaker there are other methods )

----------


## mgt

> Yes waterproofing will stick to Sika 11FC and its ok to stick the puddle flange to the shower tray.  In the link I gave you in 
> the bathroom forum http://www.renovateforum.com/f247/ez...estion-111169/  the white 
> sealant you see in the pics before the green waterproofing  is Sika 11FC. 
> Waterproofed joints ie wall/wall corner or wall/floor  etc require a bond breaker to prevent the waterproofing membrane  
> from cracking when the joint moves. As nothing sticks to silicon it can be used as a bond breaker. ie fill the 6mm corner 
> gap with silicon. The fabric tape is then stuck to the villaboard on either side of the silicon.  Then the waterproofing membrane  
>  is applied to the tape bridging the corner but allowing movement.  ( this is one type of bond breaker there are other methods )

  Goldie1, 
Thanks heaps for this post!!  Exactly the info I was after.  (easy to get confused after reading so many threads and 'guides'.) 
Does it matter which Silicon I use as the Bond Breaker?  I have a few tubes of Selleys Wet Area 'speed seal' Silicon Sealant for Bathroom, Kitchen and Laundry - which is a Neutral Cure 100% Silicon.  Would this do the job for me? 
If I end up using the Dunlop Waterproofing products, it appears that their polyester reinforcing mat for joins and corners does NOT have a "rubbery" centre, therefore requiring me to use the silicon as a bond breaker??  I would then apply this mat as directed and then paint on the membrane in the required number of coats, 2 maybe 3 (I am a belt _and_ braces kind of guy).  I will then use the Dunlop Wall and Floor Tile adhesive (premixed for convenience).  I think this is the way I will go. 
As a hypothetical (as I am learning) - could I seal the wall/wall and wall/floor joins with something like sikaflex - and then use a polyester mat WITH the rubbery centre, (which would then be my bond breaker), then apply a membrane as directed? 
Thanks again in advance. 
MGT.

----------


## Oldsaltoz

Do Not use pre mixed tile glue in wet areas. 
Pre mixed tile glue has an inhibitor to prevent it setting in the drum, by installing over a waterproof membrane and placing tiles on top replicates the conditions of it being in the drum so it will take forever to cure because it can not breath, just like it is in a sealed drum. 
Good luck and fair winds.   :Smilie:

----------


## goldie1

> Goldie1, 
> Thanks heaps for this post!! Exactly the info I was after. (easy to get confused after reading so many threads and 'guides'.) 
> Does it matter which Silicon I use as the Bond Breaker? I have a few tubes of Selleys Wet Area 'speed seal' Silicon Sealant for Bathroom, Kitchen and Laundry - which is a Neutral Cure 100% Silicon. Would this do the job for me? 
> If I end up using the Dunlop Waterproofing products, it appears that their polyester reinforcing mat for joins and corners does NOT have a "rubbery" centre, therefore requiring me to use the silicon as a bond breaker?? I would then apply this mat as directed and then paint on the membrane in the required number of coats, 2 maybe 3 (I am a belt _and_ braces kind of guy). I will then use the Dunlop Wall and Floor Tile adhesive (premixed for convenience). I think this is the way I will go. 
> As a hypothetical (as I am learning) - could I seal the wall/wall and wall/floor joins with something like sikaflex - and then use a polyester mat WITH the rubbery centre, (which would then be my bond breaker), then apply a membrane as directed? 
> Thanks again in advance. 
> MGT.

  Yes the silicon is ok it has to be dry before the tape is applied 
Yes to your second question but I don't use premixed floor tile adhesive ( read oldsaltsoz post above) 
Yes to your third question if using sika to fill the corner joints you then have to use a tape which 
won't stick to it.

----------


## wspivak

Honestly if you're trying to get the best result as a caulking product under a water based membrane, I'd avoid using silicon or polyurethane.  Get yourself a good quality MS Polymer, which is essentially a non-solvent based polyurethane (it's a bit more complicated than that, but that's the short version).  I'd recommend the T-Rex from Soudal, you can pick it up from a number of places, but Masters currently comes to mind. 
Good Luck  :Smilie:   Waterproofing products & supplies

----------


## mgt

Goldie1, Oldsaltoz, 
Thanks heaps for your explanations and advice.   
The explanation of why the premix stuff is no good for waterproofing areas makes perfect sense.  
Looks like I will go for either the Dunlop TradeFlex or the Davco UltraFlex Tile adhesive in the bag then (and probably use the waterproofing product and primer from the same manufacturer that I choose).  Use silicon as my bond breaker and the normal woven/polyester tape (either dunlop or cromelin) over the top.  (Have just noticed that the Cromelin Waterproofing membrane  does not need a primer....... might be able to skip a step??) 
Also:  Is the SikaflexFC ok to use on the wall/wall and wall floor junctions as the "flexible sealant" that will just be tiled over and NOT in an area subject to a waterproofing membrane? 
This might be a new thread topic - but as I will be putting 600 x 300 tiles on the walls (8mm thick ceramic, but one wall will be 10mm thick porcelin), the two tile adhesives I have mentioned above do state for wall and floor tiles - but neither of them are "no slump".  Do I need a no slump adhesive for these type/size of tiles on walls? 
Thanks again (for the continued questioning),
Mgt.

----------


## Oldsaltoz

> Goldie1, Oldsaltoz, 
>   Is Sikaflex11FC ok to use on the wall/wall and wall floor junctions as the "flexible sealant" that will just be tiled over and NOT in an area subject to a waterproofing membrane?  Ok for the wall to wall with a membrane tape over it inside the shower but no tape required for joints outside the shower., however the wall to floor needs a bond breaker in the shower but not outside the shower, though the wall floor joint will be waterproofed.
> Also note: Floor tiles go UNDER the wall tiles, and leave a small gap between the floor tile and the wall for expansion/ movement, fill the gap between floor tile and wall with sealant. 
> This might be a new thread topic - but as I will be putting 600 x 300 tiles on the walls (8mm thick ceramic, but one wall will be 10mm thick porcelain), the two tile adhesives I have mentioned above do state for wall and floor tiles - but neither of them are "no slump".  Do I need a no slump adhesive for these type/size of tiles on walls?  Best to post this in the Tiling forum I think. 
> Thanks again (for the continued questioning),
> Mgt.

  Good luck and fair winds.   :Smilie:

----------

