Waterproof membranes are only as good as the person who installs them!
Following on from my first post, I want to continue focusing on a Good Code of Practice regarding wet areas and in particular waterproof membranes and how they play such a critical role in ensuring the success of a healthy and dry bathroom.
With New Zealand not having a relevant Standard to reference from regarding wet area membranes, I draw my information from AS 3740 and in my opinion this should be adopted as a joint AS/NZS Standard, then a clear pathway defining performance and requirements would be established. Let’s not forget our NZBC is only ever expected to be a guide in meeting minimum requirements, but with wet areas being such a high risk area, exceeding this minimum requirement is not only Good Practice it’s good design and common sense.
Obviously every bathroom is going to be different and regardless of whether it is a shower over bath, an enclosed shower or a level entry shower, specifying a waterproof membrane that is part of a materials system and is being installed by a licenced/qualified installer is very important. A flood test and producer statement should be expected by Architects and BCAs or TAs to complete the tanking inspection and satisfy the requirements for a Code of Compliance Certificate. And please remember not all councils carry out tanking inspections, some only rely on the competency and integrity of the installer!
So firstly let’s have a look at level entry showers which are very popular and also used for disability bathrooms. These are some basic guidelines that I use and also relate back to AS 3740.
The total floor area needs to be waterproofed with the waterproofing returning up the walls a minimum of 75mm at the floor and wall junctions. In the actual shower area the waterproofing needs to be 1800mm above the floor level and not less than 300mm above the rose. Where a wall, screen or door is omitted a fall of no less than 1:50 needs to be established towards the floor waste.
A floor waste inside the actual shower area and another situated in the remaining floor area, preferably in the centre of the floor with the fall established towards it will prevent the need to establish containment at the door threshold, which I have found to be impossible anyway for obvious reasons.
Next week: shower over bath.
June 8, 2010 at 10:58 am
Hi Chris. A subcontractor who fitted our aluminium Bi-folds cleverly drilled through the aluminium extrusion in order to srew the frame down. This has meant leaking into our garage below. My question: Is there a resin or similar that I can pour into the extrusion in order to stop the water flow?
Cheers Paul S
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Chris Withers:
June 8th, 2010 at 1:13 pm
Hi Paul,
I think the most practical way of fixing this would be to remove the fixing screws one by one and filling the hole with a silicon sealant and re fixing the screw with a rubber washer around the head and then using some loctite to seal the washer and screw head. It sounds like it has been installed incorrectly in the first place and I would also be asking the question back at the installer as to why it has been installed like this in the first place. I hope this helps.
Thanks,
Chris W
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June 8, 2010 at 12:17 pm
does the bifold not have a reveal around the inside where he could have fixed it properly.if it has i would be asking him to come back and fix it. hmmmmmmm maybe not if he couldnt work that out
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Chris Withers:
June 8th, 2010 at 1:14 pm
Hi Jim,
Yes I agree, seems like a very strange way to install.
Thanks,
Chris W
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June 9, 2010 at 9:42 am
Hi Chris
We have recently had a client who wants to have under tile heating in there tiled shower. We have explained that the hot water from the shower will heat the tiles sufficiently so that they are not cold on their feet, however it appears that the main reason they want it is to help dry the shower enclosure.
Have you had any experience with this? If not, do you know of any reason that it can’t be done?
The remainder of the bathroom will have under tile heating.
[Reply]
Chris Withers:
June 9th, 2010 at 10:28 am
Hi Karl,
Yes this can be done for a shower floor as long as it has a sand and cement screeded base as opposed to an acylic based shower floor.
I would do it this way.
1. lay the underfloor heating matt in the shower.
2. screed the floor over the top of the heating matt with the fall established back to the waste, make sure the cement screed is a minimum of 25mm thick and I would suggest an Allproof tile grate with PVC spiggot waste.
3. Finish the cement screed with a steel float as to make the finished surface very smooth and to prevent a loose sandy top.
4. Apply a waterproof membrane to the fully curred cement screed and tile.
The guy’s from Warmup NZ have a great underfloor heating product and they have experience in this type of proccedure. I also only use polyurethene type waterproof membranes such as Dampfix PU from ASA/Bostik.
Hope this helps
Regards,
Chris W
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Karl:
June 9th, 2010 at 10:40 am
Thanks Chris
All makes sense. Much appreciated…..
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June 10, 2010 at 3:33 pm
Hi Chris,
My shower recess, tiled and level with floor and no hob, has failed and the wall framing has started rotting. Would it be best to remove all the tiles making good to the framing and starting again with the waterproofing or is there any tile surface application adequate enough to reseal the shower recess. Or would the second option only be a temporary measure.
Regards,
Graham B.
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June 10, 2010 at 3:34 pm
Hi Chris,
I have a client who is keen to have an obscure window included in their tiled shower. I have spoken to a joinery supplier and received from them a detail utilizing a standard residential window extrusion. It shows the aluminium frame fixed to the building structure with a metal fixing angle. The tiles over waterproof membrane on ply fixed over the fixing angle and frame – with the tiles being sealed off against the glass with sealant on PEF backing rod.
I would like to utilize an opening top sash for ventilation, and was keen to hear about an alternative detail that didn’t feature the tiles being sealed off against the glazing.
Thanks,
Regards Greg.
[Reply]
June 10, 2010 at 4:13 pm
Hi Graham,
There are a few products available that say they can re-seal tiles and grout for a leaking shower, however I dont personally rate them as they are only a temporary fix and do not address the real issue of what is causing the leak. First have a close look at the tiles and make sure they are not cracked, slighty loose or that the grout has come away from the edge, if this is so lift and replace them and it may be a quick fix although if the framing has started to rot it really needs to be replaced.
Have a look at the grout, a moisture problem will identify itself by showing up as a pink or orange colour in the grout. Some typical volnerable area’s are at the intersection of the walls and floor, silicon tends to shrink over time and this may have exposed the junction to water. Make sure your waste is completly sealed as well and my personal favorite the holes in the walls where the shower mixer and rose, or perhaps taps are, if they are not sealed this is also another area where moisture will enter the cavity.
In all honesty I would recommend that a re build is the way to go if one of these area’s prove to be the cause of the problem. I see you have an Australian email and one thing I have noticed in Aus with tiled showers is that the junctions are normally only waterproofed and a waterproof membrane is typically not used at all. If you do decide to rebuild I would recommend a waterproof membrane is used in conjunction with a tile adhesive that makes up a system, ASA, Construction Chemicals, Mapai are all available in Aus and are fantastic products that have a waterproof and tile system. And an Aquatite Wetwall Caddy will seal the penetrations for the mixer and rose (shower pack) or hot and cold tap (tap pack). Look out for any black mold that may be present in the wall cavity as it is dangerous once exposed to warm air and light so a beathing mask is needed to safly remove any rotton timber. Hope this helps,
Regards,
Chris
[Reply]
June 10, 2010 at 4:30 pm
Hi Greg,
Sounds like a good way of waterproofing this sort of detail, perhaps a simple L angle to terminate at the edge of the tiles rather than having them sealed against the glass would be better? This angle is typically available in a number of sizes to suit the thickness of the tile 6,8,10,12mm. I would suggest installing it on top of the plywood and waterproofing it onto the ply, then butting the edge of the tiles into L angle. They have a very small return on the top leading edge and this makes for a neat finish. Hope this helps or you can send me the detail and I can have a good look if you like.
Regards,
Chris
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Greg Edwards:
June 10th, 2010 at 4:41 pm
Thanks Chris – I’ll draw a couple of options and shoot them through to your email if you’d be kind enough to comment.
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June 10, 2010 at 4:54 pm
No problems Greg, send them to chris@aquatite .com
Thanks
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June 12, 2010 at 9:37 am
Hi,
Thanks for your support, keep any eye out over the comming weeks for some information on a very innovative enclosed shower system that out performs anything else on the market today.
Regards,
Chris
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June 20, 2010 at 11:11 am
What are your product guarantees
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June 20, 2010 at 3:10 pm
Hi Clive,
All of the Aquatite products have a 50 year consumer and product warranty and come with a producer statement for code of compliance documentation.
thanks,
Chris
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June 22, 2010 at 12:38 pm
interesting reading. very informative and detailed. will be keeping an eye out for future articles.
Regards,
Jane
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Chris Withers:
June 22nd, 2010 at 3:37 pm
Hi Jane,
Thanks for your comments, much appreciated.
Regards,
Chris
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June 28, 2010 at 9:08 pm
Hi Chris
Congratulations on your very informative blogs. I wanted to put your Aquatite Caddy system on our new shower, but have had a huge battle with the plumber who is adament they are unnecessary. He is determined not to put them in saying his work does not leak. I told him about sealing the holes up in the wall but he still thinks the products are a waste of time and will cost me too much to install (meaning his labour charges). How do you think I should handle this? Surely he has to put them in if I ask him to or can he refuse?
Regards
Kirsten
[Reply]
June 29, 2010 at 10:11 am
Hi Kirsten,
Thanks for your comments.
I dont know what it is about plumbers and the plumbing industry in general?? I have heard from many manufacturers who say that plumbers are terrible at adopting change and innovation of new products and are a law unto themselves.
The simple answer is that your shower mixer needs to be installed with an access hole left in the wall lining, this can be anywhere from 55mm to 102mm depending on which shower mixer you have purchased. Common sence tells you that this access hole needs to be sealed to prevent the passage of moisture past the wall linings and into the wall cavity. That is a code requirement.
Feedback form plumbers who do utilise the Aquatite products tell us that they take around ten minutes to install so this is not and should not be an issue. There is no excuse for ignorance and if he still refuses to do as you wish, find another plumber who will listen to you, in fact if you would like to contact me via the Aquatite website and let me know where you are, I will supply you the details of a plumber in your area who is happy to install a Wetwall Caddy for you.
Thanks,
Chris
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Kirsten:
June 29th, 2010 at 10:42 am
Thank you for your comments Chris. I will give him one more chance when he comes back in the next day or so. If I don’t have any luck, I will contact you to arrange another plumber as I think your products are fantastic and should be installed every time a shower is built.
Once again, thank you for your help
Kind regards
Kirsten
[Reply]
June 29, 2010 at 11:12 am
No problems, good luck.
Cheers,
Chris
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August 6, 2010 at 11:46 am
Hi Chris
We recently put in a new bathroom with an open wet area shower. The floor was waterproofed and the walls up to 2m in the shower area and up to 1.5m around the rest of the bathroom.
A trench from Allproof was installed, which after wrong installation initially was re-installed with the double drainage both from under the tiles along the waterproofing and on top. The waterproofing was re-done and the tiling was re-done and everything seemed fine. What we have noticed since is that the grouting in the shower is fine but in the areas adjacent to the shower area seems to be wet and there seems to be some leaching appearing – a white salty substance. I am not sure whether this could mean that there is pooling under the tiles between the waterproofing and the bottom of the tile.
What do you recommend we do? There is minimum fall in the floor as per standard.
Catherine
[Reply]
August 6, 2010 at 1:58 pm
Hi Catherine,
Typically the white salty substance you describe is normally associated with water under the surface of the tile. This is common with porcelain and terracotta tiles which are not glazed as is a ceramic tile. A light coloured grout will tend to go a pink or orange colour where as grey or black grout will go white if moisture is present. It will not take much to raise the fall level of a floor especially if it has been opened up and re-waterproofed and re-tiles as you mention…if you can imagine the amount of fall over an area of say 1.0sqm would be less than 2mm it won’t take much for that to be built up level or to a negative fall if extra waterproofing and tile adhesive has been added in trying to fix the initial repair. Here is what I would do in the first instance.
1. wipe down the effected tiles with white vinegar as this will neutralise the salty appearance.
2. Monitor the tiles over the next few day’s and if it returns, then I would be contacting the tradesman and asking him to put it right.
3. In general have a really good look around the effected area where the repair was conducted and look for any tell tale signs of a breach especially around the trench waste as this is where all of the water is being directed too in the first place and may be where the problem has a starting point. They are a fantastic product Allproof Trench waste’s and I highly recomend them, unfortunatley as is with any product they need to be installed correctly in the first instance and any type of re-installation of any product can be very hard to get done right…as it seems to be in this case.
I hope this helps.
Chris
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September 23, 2010 at 10:25 am
Chris, your article is great. I have made notes for future reference- Thanks
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Chris Withers:
September 27th, 2010 at 11:49 am
Hi Rosemary,
Thanks for your comments.
Regards,
Chris
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November 5, 2010 at 9:27 am
Hi Chris – interesting reading, I am an architectural technician but having recently returned to NZ after a long stint overseas and working in a different industry i’m still becoming familiar with products here in NZ.
we are currently renovating our house and at the moment we are sorting out a new bathroom. we are installing an atlantis easy tile level entry shower system over timber flooring and i am currently getting quotes for the tiling and waterproofing membrane to be installed. One tiler who seems quite good has said he would use Ardex superflow WPM001 is this a water proofing membrane you would recommend? we want to ensure our wet area remains dry where it is meant too!
[Reply]
Chris Withers:
November 6th, 2010 at 10:40 am
Hi Tony,
Thanks for your comments, I recommend Waterproofing Systems http://www.waterproofing.co.nz Duro range of waterproof products to all of the architects I talk too as they are Branz appraised and are installed by certified installers, a producer statement is issued and they have a wide spectrum of products that will suit any type of application. I would also reccomend you visit http://www.aquatite.com and insist your plumber installs a Wetwall Caddy to seal the penetration in the wall for the shower mixer and rose, this in conjunction with the quaility of the Duro range of waterproof membranes and a professional installation will ensure your wet area bathroom remains dry. I hope this helps and please feel fre to contact me again if you require any further information.
Cheers
Chris
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