Prevention is the Key to Sustainability and is always better than having to find a cure.
So let’s have a look at a Good Code of Practice for waterproofing areas associated with a shower over a bath and in particular how doing a little bit extra at the design stage will ensure that the weaknesses and oversights in E3′s minimum requirements don’t come back to haunt.
Using an example of a tiled shower over bath, the waterproofing areas need to be the same as all tiled showers, i.e walls to a minimum of 1800mm above the floor and a minimum of 300mm above the rose and out to a width of 1500mm along the wall.
These are the guidelines set out in AS3740 and recommended by manufacturers of waterproofing membranes as there is no requirement in E3 that states that a waterproof membrane needs to be installed at all. So installing one is a good code of practice and defines this as a Wet Area as opposed to a Splash Area which only has a requirement to be water resistant.
Where at all possible I have always favoured installing a waterproof membrane under the actual bath as this protects the floor area from any water damage that can occur from a number of areas such as moisture penetrating through the seal on the bath lip and wall junction (very common) and entering into concealed spaces where it is not seen.
Sealing the penetrations in the wall itself is very important and will prevent water ingression issues or hardware failure from tapware products leaking inside the wall cavity. Having the penetrations sealed also complies with E3.3.5 and is part of the integrity of the waterproofing.
Why is the use of a single lever mixer for the operation of the shower and another single lever mixer for the control of the bath better than the use of a diverter mixer?
Pretty simple really, why leave the warmth of a hot bath to turn the water on when having another single lever mixer situated in the middle of the adjacent wall allows you do the same thing without having to move.
Coming up next time: A new enclosed shower system that incorporates a number of quality products to make it a true leak free system!
June 11, 2010 at 8:57 am
Chris
has the Aquatite been a succesful product in our market
have you had much resistance to it especially around installation
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June 11, 2010 at 3:28 pm
Kelly,
Having to create a market for a new concept and product has been challenging and yes resistance around installation is an initial hurdle with plumbers as I think you may know. But as I have been told by many a person and company who have also developed new products here in NZ, getting the trade to up take and utilise something new takes a lot of time, money and effort and without the support of some merchants takes even longer to draw sales thru their shareholder/customer base. Has it been succesful in our market? Well time will tell as it has only been 4 years. The Wetwall Caddy is a very simple product to install and there are many plumbers using them, have a look at the installation instructions available on the Aquatite website to see for yourself or please feel free to call me if you would like to discuss this further.
Thanks
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June 21, 2010 at 3:24 pm
Hi Chris,
Best practise as you say is to use a “waterproof membrane” how can you ensure a tradesman does and uses top quality products? Other there are “insurace policies” that home owners can use/install when renovating our dream bathroom?
Thanks
Mel
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June 21, 2010 at 4:04 pm
Hi Mel,
If you are going to use an Architect or Designer to design your bathroom renovation they will/should specify a waterproofing system that meets or exceeds all building code requirements and has a producer statement to comply with your council requirements to satisfy a code of compliance certificate. Alternatively if you are going to design and project manage this renovation yourself and there is no requirement for a consent i.e A like for like renovation and there are no changes in water points and drainage from your existing bathroom or you are not installing a wet area/level entry shower, you can discuss all product and proceedure requirements with your builder and tiler. I would also be asking them to supply a producer statement for the waterproofing membrane that they are going to supply and install and insist they perform a flood test prior to the commencement of any tiling. This is a standard proceedure that is used by quaility tradesman and such an important part of ensuring the sustainability of your new dream bathroom and should not be overlooked or under estimated by your tradesman. Ask for a gaurantee for their work as well, as most quaility builders, tilers and waterproofers will already have these type of consumer gaurantee’s built into there work practice’s anyway and if not use one that has. I hope this helps.
Thanks,
Chris
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June 25, 2010 at 9:55 am
Hi Chris,
You’re right on the money with your comments regarding water proofing around and under baths with showers over. This could also be applied to all baths in general. As an ex-plumber I have all too often seen the results of leaks in the joins around baths, let alone baths with showers over. Not only does the NZ Building Code need updating, but a tighter rein is needed on all tradesmen involved with this type of installation. For example I have seen untrained people installing tiles and waterproofing systems and while I accept the local authorities have tightened up on their inspections in this area, I believe more needs to be done. Things are starting to change with the introduction of the licensed Practitioners scheme, but will this be enough, I’m not so sure. Another area of improvement could be in the way our baths are made, surely a larger lip around the outside would help to prevent leaks.
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June 25, 2010 at 12:08 pm
Hi Steve,
Thanks for your comments, yes a good code of practice needs to be adopted for not only this area but many others as well regarding internal moisture. I have spoken to a number of bath and tapware manufacturers about improving the design on areas that have well known leak/risk points, unfortunatley their focus is on how products look and not how well they perform. I think the more that issue’s like these are discussed and awareness is made about how to achieve a better way of designing and building, the better off we will all be. and I agree about the BCA’s and TA’s tightening up on inspections etc but there are still a few large councils around that don’t do tanking inspections, rather they rely on the integrity of the installer and as you said this can be done by anyone. I hope that the licensed practitioners scheme does go through as it will sort out the cowboys, but already their is some resistance from some tradesman, I noted a local plumber from my area having a protest about this outside parliament last week.
Regards,
Chris
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June 28, 2010 at 11:11 am
Chris
Coincidentally I have been through E3 a few times lately looking for exactly that: a requirement for a waterproof membrane to be installed. I realise it is good practise, like you said, but is it at all necessary to install an impervious material over a well sealed GIB aqualine lining painted with water resistant sealer and top coat?
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June 28, 2010 at 1:13 pm
Hi Ben,
You won’t find a requirement to install a waterproof membrane in E3 as there is no requirement to do this. A waterproof membrane should be installed for a shower area that has tiles over the wall substrate, as tiles with their grout joints are not classed as impervious. An acrylic lined shower can get away with not having a waterproof membrane as this can be classed as impervious. So anything outside of the shower area that does not fall into the catorgory of a wet or splash area should be fine with a water resistant sealer and top coat. Aqualine as you may well know has a modified polymar in the core of the board which makes it water resistant so protecting the face is a good idea too. The most important thing to remember regarding E3 is the requirement to prevent the passage of moisture past the linnings and into concealed spaces, so the sealing of the penetrations in the wall lining is paramount to ensure that this minimum requirement of E3 is met.
I hope this helps,
Thanks,
Chris
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Alec De Martin:
July 15th, 2010 at 3:00 pm
Chris, (and others).
The Membrane Group is in the final stages of writing the Code of Practice for Wet Areas, similar to the one for Torch-on Membranes, (which incidentially has been universally accepted through out NZ by the industry) . What has surprised us (and why it is taking longer than we expected) are the large number of systems, products and finishing overlays that all need to be considered and included. We are also aware that the Dept is looking at re-writing E3 so we need to ensure the Code and the new E3 say the same thing. But please be assured, there will be no room for different interpretations of what the Code says, it will be precise and clear. This code of practice is one of a suite of codes that will cover all types of waterproofing.
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July 16, 2010 at 11:19 am
Hi Alec,
Thanks for that information. I will keep my fingers crossed that the DBH do actually review and or amend E3 and it’s associated compliance documents.
Thanks,
Chris
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October 29, 2010 at 3:35 pm
In the Far north district the proceedure is that they demand a Producer Statment for the membrane tanking product and for the installation and presently will not approve a product without a Branz appraisal so if anything fails they are not liable in any way.
That seems to be their entire attitude , less work , less time and more profit.
s
So doing any additional inspections is not in their interests.
Finally using the best available products with the best detailing and specification is the only viable methodology and that is assuming that everyone involved is educated and aware of the science and technicalities involved with handling water and knowing how it behaves.
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Chris Withers:
November 4th, 2010 at 5:11 pm
Hi Hans,
Thanks for your comments. The requirement to provide a producer statement for waterproofing is a requirement from all councils as far as I am aware, which is a good thing as it also aligns the manufacturer of the waterproofing products with the installer/applicator who should be trained and certified to install the specified waterproofing system in the first instance.
I am a little concerned that the Far North council are not allowing the installation of non “Branz appraised” products though as there are some products that do not have Branz appraisals and are vital componants to the the successful water tightness of a wet area, for example there are no shower mixers that have a Branz appraisal, floor wastes do not have a Branz appraisal and Aquatite have not renewed their Branz apprasial simply as the cost of renewing/rubber stamping the appraisal certificate every year is very expensive comparred to the actual cost of the product.
I agree that using the best detailing and specifing products that out perform the minimal requirements of the building code is the most viable way to ensure a water tight enviroment and the more in formation that is available to educate the building industry the better, but as the old saying goes…you can lead a horse to water but you cant make it drink.
thanks,
Chris
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October 29, 2010 at 3:38 pm
Ps . it seems especially silly that age old proven products and methods utilising materials such as stone can only be used as ‘alternative solutions’, that needs to change!
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