The Weathertight Risk matrix covers items that are primarily E2 watertight construction issues. For materials or construction methods that are likely to fall short of requirements see the general riskmatrix.
Note: This limitation is to encourage good low risk design while allowing flexibility
Ease Of Detailing and Construction
Consequesnce of failure
E2 or manufacturers detail
Deflection
Drainage
Drying
Duribility
Total
When working through the weathertightness risk matrix, more than two orange items on a single build is prohibited and will require designing these back to a green solution.
The reason behind this is that all evidence and precedence suggests that failures are far more likely to occur if multiple high risk details are used in conjunction with each other. An example of this would be a risky roof junction detail used in conjunction with no eaves. Removing eaves in such an instance reduces the overall protection on the junction detail, thereby magnifying any risk further.
Even if the details appear unconnected it is still prohibited to contain more than two orange items. To further clarify if an orange on the matrix, occurs in two different areas of the building and requires two seperate details but still under the same catergory, then this must be deemed to be 2 oranges.
Please always remember that an orange item should be designed against – there are often better ways of approaching such detailing and this is designed to ensure that all risks are appropriately managed. If in doubt speak with your design team.
This detail is often prone to leaking. On an external wall the soil behind will be high in water content and poses a risk with water migrating internally, creating potentially significant remediation requirements.
This is an extremely high risk detail and should not be undertaken. Where required consideration to separating the building from the retaining element should be given.
Further Info - https://www.buildmagazine.org.nz/assets/PDF/Build-153-32-Design-Right-Down-And-Dirty.pdf
Further Info - BRANZ Build Magazine Basement Issues
More common detail than that above, however this has risk in water flowing from upper cavity to lower cavity. This detail should be carefully undertaken and managed accordingly.
Areas of Caution
Use of a chased flashing into the step to direct water away from the framing changes this item to a green or permitted detail.
Whilst bricks above openings are not a problem, care should be taken where overall brickwork height is less than 300mm above opening. Small overall height amplifies any movement which can create cracking within brickwork.
Change of claddings at internal corners is a robust detail. Always ensure that manufacturers details and used and referenced, this helps ensure all warranties are maintained.
Where manufacturers details are not available then utilise E2/AS1 detailing.
This detail should always be avoided where possible. Move cladding changes to internal corners for risk reduction.
Cladding junction exposure to weather is high and corners are generally filled with cavity battens which creates additional risk through reduced drainage and drying.
Where unavoidable always ensure that manufacturers details are used and referenced, this helps ensure all warranties are maintained.
Direct fixed claddings should not be utilised. The recent knowledge gains through repeated weathertightness issues within NZ confirm the benefits of a vented cavity on overall weathertightness.
Some cladding manufacturers suggest that direct fix can occur within a specific E2/AS1 risk matrix score. This should still be avoided as a cavity represents significant durability improvements for limited overall cost.
Low risk, accepted detail as per Acceptable Solution under E2/AS3.
Enclosed parapet with internal gutters should not be constructed. Extreme care with detailing and construction is required and this is very difficult to achieve, i.e. construction is not ‘a perfect world’. Do not make the mistake of thinking your trades or draughtees take more care than most.
There are multiple outlets and penetrations which can fail with blockages. Any failure directs water to the inside of the building creating significant risk of leaking and remediation.
Always remember, the primary function of any roof is to ‘umbrella’ the building. This umbrella effect ensures that water is shed away from the faces of the building and represents the most effective way of securing long term weathertightness, a key function of any building.
Customers likely perform very little maintenance on roofs given the difficulties of access. It is important to understand and advise your client of potential risks within the primary weather defence line.
Further Info - Build Magazine - Parapet http://www.buildmagazine.org.nz/assets/PDF/B112-18-Parapet-Balustrade.pdf
Parapet walls impede on the primary roof ‘umbrella’ function and should be avoided.
Parapet walls within 150mm of wall end create additional risk through the weak point being at the wall end. With additional cavity battens at the corner this creates added risk of reduced drainage and drying. This detail should not be constructed.
Remember, customers likely perform very little maintenance on roofs given the difficulties of access. It is important to understand and advise your client of potential risks within the primary weather defence line.
Further Info - Build Magazine - Parapet http://www.buildmagazine.org.nz/assets/PDF/B112-18-Parapet-Balustrade.pdf
Parapet walls impede on the primary roof ‘umbrella’ function and should ideally be avoided.
However this protruding detail with 150mm setback from the wing wall end allows for the use of an E2/AS1 detail and moves the junction back from the cavity battens seen at the wall end. This allows for better drainage and drying.
This detail is only orange when in line with E2/AS1, otherwise all parapet roofs should be avoided.
The wing wall moves the weaker point outside of the building envelope, creating a much lower risk of consequential damage.
Secondary issues around parapet capping with corners are also higher risk details and need to be considered.
Please note that E2/AS1 prohibits parapet walls where the face of the parapet is in line with the adjoining wall.
Remember, customers likely perform very little maintenance on roofs given the difficulties of access. It is important to understand and advise your client of potential risks within the primary weather defence line.
Single plane roof at lower pitch without valleys or protrusions are relatively low risk.
Care does need to be taken to ensure that low pitch flashings are in place and sized in accordance with E2/AS1.
E2/AS1 also requires that eave flashings are in place to prevent the ingression of water through blowing back up under the roof.
Remember, customers likely perform very little maintenance on roofs given the difficulties of access. It is important to understand and advise your client of potential risks within the primary weather defence line.
Roof has multiple planes or obstructions. Due to the lower pitch valley gutters are prone to blocking from debris, or even hail. This is because of the slower pitch drainage, but also the angle creating an overall shallower valley gutter.
Care does need to be taken to ensure that low pitch flashings are in place and sized in accordance with E2/AS1.
E2/AS1 also requires that eave flashings are in place to prevent the ingression of water through blowing back up under the roof.
Try to utilise a simpler roof form and design out valley gutters to reduce overall risk.
Remember, customers likely perform very little maintenance on roofs given the difficulties of access. It is important to understand and advise your client of potential risks within the primary weather defence line.
Membrane roof open to lower side flowing in to standard gutter.
With only 1 degree of minimum fall between membrane and alternate steel roof cladding better options are available. This detail should therefore be designed against.
Membranes roofs have historic mixed performance therefore should be avoided.
Always remember, the primary function of any roof is to ‘umbrella’ the building. This umbrella effect ensures that water is shed away from the faces of the building and represents the most effective way of securing long term weathertightness, a key function of any building.
Customers likely perform very little maintenance on roofs given the difficulties of access. It is important to understand and advise your client of potential risks within the primary weather defence line.
Enclosed roofs should not be constructed. Extreme care with detailing and construction is required and this is very difficult to achieve, i.e. construction is not ‘a perfect world’. Do not make the mistake of thinking your trades or draughtees take more care than most.
There are multiple outlets and penetrations which can fail with blockages. Any failure directs water to the inside of the building creating significant risk of leaking and remediation.
Always remember, the primary function of any roof is to ‘umbrella’ the building. This umbrella effect ensures that water is shed away from the faces of the building and represents the most effective way of securing long term weathertightness, a key function of any building.
Customers likely perform very little maintenance on roofs given the difficulties of access. It is important to understand and advise your client of potential risks within the primary weather defence line.
This is a common an acceptable detail.
However, significant care is required from the roofer in diverting water away from the valley gutter.
In general with this detail water is directed outside if there is an issue, however always ensure that windows or penetrations on the higher wall clear the soffit and gutter.
Always design away from these, they should not be constructed.
Extreme care with detailing and construction is required and this is very difficult to achieve, i.e. construction is not ‘a perfect world’. Do not make the mistake of thinking your trades or draughtees take more care than most.
Leaves or other debris can very easily block outlets or drainage path, directing water inside of the building.
Always remember, the primary function of any roof is to ‘umbrella’ the building. This umbrella effect ensures that water is shed away from the faces of the building and represents the most effective way of securing long term weathertightness, a key function of any building.
Customers likely perform very little maintenance on roofs given the difficulties of access. It is important to understand and advise your client of potential risks within the primary weather defence line.
If a leak occurs at roof junctions this affects the building envelope weathertightness and can cause significant issues.
E2/AS1 details and setbacks can be used in this instance to provide reduced risk. Detailing and setbacks helps control risk of failure.
Attention should also be paid to the clearances above roof for any windows or penetrations. E2/AS1 provides minimum distance guidance.
This detail should not be constructed. No E2/AS1 detail exists and roof junction detailing becomes extremely complicated and risky.
See above detail for alternative. E2/AS1 requires a minimum 150mm separation/setback. The use of building form allows negation of this detail and is therefore a better alternative.
Comment from E2/AS1: Reports on leaky buildings show these junctions have been prone to leakage and care must be taken to detail and build them correctly. In-plane junctions require specific design of flashing arrangements.
This detail is riskier than similar eaved details.
The risk comes from a lack of protection to window heads and water travelling below the roof, migrating in toward framing, ceiling or behind claddings.
Always remember, the primary function of any roof is to ‘umbrella’ the building. This umbrella effect ensures that water is shed away from the faces of the building and represents the most effective way of securing long term weathertightness, a key function of any building.
This is an acceptable detail.
Eaves still have a soffit. With brick cladding this may appear flush, but still retains soffit and fascia.
Always remember, the primary function of any roof is to ‘umbrella’ the building. This umbrella effect ensures that water is shed away from the faces of the building and represents the most effective way of securing long term weathertightness, a key function of any building.
This is the ideal eave detail, being extremely robust for NZ climatic conditions.
Always remember, the primary function of any roof is to ‘umbrella’ the building. This umbrella effect ensures that water is shed away from the faces of the building and represents the most effective way of securing long term weathertightness, a key function of any building.
Using 600mm eaves wit a 25-27 degree roof pitch allows for windows to go to the soffit with out any cladding above the windows while still allowing for a 300mm lintel which reduces cost.
Not Permitted
Permitted
Issues With Skylights
Condensation
Often when a skylight is thought to be leaking, the issue will be condensation. Condensation occurs when when warm damp air is cooled suddenly. The warm air which can carry more water vapour than cold air needs to release this water vapour when it is cooled and will do so on the sufaces surounding it. We see this in geographical locations from down in the cold south to the sunny north and has more to do with relative humidity and dew point than location.
Skylights are a prime area for condensation to form as the surrounding ceiling is well insulated and will be warm and able to hold any moisture present in the air of the home. This air will then be rapidly cooled by the skylight which will be reasonably close to the air temperture outside.
So what does this look like in practice? If a home is heated to 20 degrees inside and has a relative humidity of 65% then you will start to see condesation occur when the surface of your skylight hits 13 degrees. This is not an extreme temperture but something that will occur in most seasons in New Zealand. We are more likely to see humidity levels closer to 80% in winter which would mean we are getting condensation at 18 degrees
This condensation is not only damaging to surrounding surfaces but is unsightly and at the height of installed skylights hard to clean.
Thermal Efficency
Double glazed skylights are often compared to double glazing in window joinery, however the R value of double glazing drops as it is moved off vertical with around a 30% redcuction in r- values for skylights in roofs. This is due to the internal convection currents in double glazing. A 550 x 980 Velux double glazed sylight will have an R-value of just 0.35 compared to the ceiling around it of R6.6.
The position of these also adds to the thermal efficency issues. Normally located in our main heating zones and in a position where the air is warmest , the transfer of hot to cold will be higher than a window located in the walls
Solar Gain
Skylights are a double edged sword when it comes to keeping homes at a comfortable temperture. They allow heat to exit a home easily in winter and allow solar heat gain in summer. Care needs to be taken on their position to avoid overheating of areas during summer months.
Cleaning
Depending on where in the roof the skylight is cleaning of these can be problematic. We quite often see these at heights of 4-5m.
Watertightness
Always remember the primary function of any roof is to ‘umbrella’ the building, therefore anything penetrating this umbrella will undermine its main function – to shed water away from the building.
Skylights on a steeper pitch (12+ degrees) can be used however extreme care toward detailing is required to ensure longer term performance and the validity of manufacturer warranties.
E2/AS1 specifies distances for upstands and back flashings which can assist.
It should be noted that a large European manufacturer once suggested that skylights will always leak at some stage in their life. This is likely beyond the G.J. warranty period, but it is an important note for customers to consider.
NOTE: This was moved to Orange 8 August 2023.
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Intent With Changes to H1 and better knowledge around thermal efficiency, all efforts should be to move our clients away from skylights. We know have R6.6 insulation in our roofs while skylights generally sit around R0.4 depending on size. While a skylight can add daylight to a room it will only provide warmth in summer when we want it the least and will cool the house when we are trying to heat it. A much better way of adding daylight is with solartubes or designing so the house receives enough light from the windows. |
Membrane decks overlaid with either tiles or decking represent a significant potential for moisture ingression. The level of consequential damage can be significant when deck is over a living area and therefore should not be constructed.
Membrane covers are susceptible to cracking or failure through repeated thermal expansion and contraction. It is highly likely therefore that these membranes will fail over the lifetime of the building, creating a significant problem and remediation requirement.
Customers need to be extremely careful when considering such a detail with any builder. Any promises of “a better way” or “extremely skilled trades” is false sales promises. G.J. Gardner will not build these as it is morally wrong to do so.
Membrane decks that have post protrusions require complex detailing and welding of the membrane, representing significant risk. These should therefore not be constructed.
Furthermore, if the post is not clad, water can enter the top of the membrane. Once water is inside of the membrane no drainage is available to safely remove the water and drying ability is reduced due to no airflow. This again creates a significant risk of failure and remediation.
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Intent Generally we should discourage the use of membarane decks due to the durability and difficulty of deyailing however membrane decks are required in some medium density develops to comply with fire regulations. If this is the case the simpliest form should be used. |
Pergolas attached to buildings that requires penetrating the envelope and creating a pathway for water to enter should not be constructed given the increased risk of moisture ingression.
As these fixings go back to the frame they also allow water beyond the building wrap and cause wetting of the building frame. This creates an unacceptable level or risk and therefore these should not be constructed.
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Intent Pergolas can still be accomplished by standing off the house on posts. This also allows for the pergola to be changed with out alterations to the home.
If they must be attached to the house then under the sofffit is a better option, however consideration should be given to the weight of the pergola |
Houses with soffitts offer the option of attaching the pergola to the soffit framing, this is a much more acceptable detailing than attaching back to framing which risks water ingression.
Ensure that the truss manufacturer is aware of any extra load created by this and that extra timber is provided as necassary for fixing.
Buildings that have horizontal seperated tenacies require a very different skillset to either detached homes or vertical seperated tenacies like teraced house. Fire stradegies as well design and instalation of services require special knowlede to get the best results.
Failure of any aspect of these buildings can be catestrphic and include damages to tennances.
The Requirements
Not Permited
Permitted
The Reasons
Dark colours which go through stages of popularity have many draw backs when it to comes housing, and it is even worse when it comes to New Zealand housing. For GJ Gardner it is not just about the claddings ability to withstand heat, but about what is in the best interests of our clients. We have three areas of concern.
"Ultra Violet light is the heat causing portion of the light spectrum. It is the same light that causes sunburn. Different colours will have the different levels of UV absorption, with white absorbing very little UV and black absorbing almost all of it. When we have used a thermal camera to test surface temperature of claddings, white has been slightly warmer than air temperature while black has been almost three times that.
While products like James Hardie CFC (Compressed Fibre Cement) do a reasonable job of handling the heat, they are not immune from the effects and still suffer from thermal expansion ie a length of Linea will be longer in hot tempertures than cold tempertures. This makes it harder to join these as overtime the jointing compounds will weaken and fail. On other boards like Axon this leads to white lines where boards overlap. Not only does the heat make the effects of this worse but the colour highlights any movements that occur as the light colour of the boards themselves will show against the dark colours.
Consideration must also be given to components of the James Hardie systems that are not CFC such as the timber scribers. These timber scribers are normally only warrantied to an Light Reflectance Value (LRV) of 45% or lighter. This is to prevent the resins in the timber from melting or bleeding which causes the paint to lift. Heat will also cause the timber to spilt, warp or shrink.
The heat from the claddings will also transfer to the frames of the home causing movement and cracking in the gib on the inside of the house.
This same UV light and heat causes two issues for the paint, firstly what is known as chalking. This shows up as a patchy colour to the paint finish and when the surface is wiped it will leave a white chalk like substance on your hand and is a sign that the paint is breaking down. Darker colours absorb more energy (heat and UV radiation) from sunlight than lighter colours thereby putting greater stress on paint coating. High UV intensity and greater energy absorption will result in more deterioration of the paint surface. Also, chalking is visually more obvious on darker colours.
This means that dark colours will need far more maintenance than lighter colours. Where as a well maintained light house may last 12 years before needing a repaint a dark house may be showing signs of fade within five years
Black houses are best thought of like black cars in that they will need cleaning more often and every little mark will show. The materials we use are not perfect with linea being a prime example. To achieve the required finish level on dark colours the board needs a lot of additional work and even then is unlikely to finish in a way that is acceptable to our clients.
Be very cautious of coastal areas where the salt in the air will quickly show on dark surfaces
Resene Cool Colours and Dulux Colourgaurd
Both these colours use reflective particles in the paint that reflect UV and are highly effective at reducing heat and colour fade. A bit like sunscreen for a house. These paints are a requirement of the risk matrix if colours with an LRV of less (darker than) than 40% are used and while they help reduce heat build up and fading, they show defects and need more cleaning than lighter colours. There is also more cost involved in applying these to our homes
Light Reflectance Values (LRV) between these paints will remain unchanged, but their Total Solar Reflectance (TSR) will change, which is the paints ability to reflect the UV light. This will be considerably lower with these paints but is not recognised by manufacturers of products like timber cladding so is not a cure to the issue of dark colour heat build-up.
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The Intent Our discussions with our clients should be directed at showing the benefits of using lighter colours. It is not just about the claddings ability to withstand the heat, but a whole lot of things that should be part of the discussion. I.e., is a client happy that their 5-year-old home, which they will still consider new, is fading or that their house that is in a sea spray zone and will look dirty after every decent swell. I would want my builder to explain these things to me, so I could make an informed decision. This discussion is made challenging if we use colours on our Showhomes that go against the advice we should be providing. To support this discussion Showhomes must have paint colours selected with an LRV (Light Reflectance Value) of at least 40% and any timber components must be painted in accordance with the manufacturers of these products. |
Abodo warranty is sub-standard, with only the timber treatment against decay covered. Many other common timber problems are excluded, alongside warranty being limited to first owner only making any future issues difficult to pursue.
| Consider JSC Thermally treated timber as an alternative. It starts with a timber that is more durable than pine used in Abodo and comes with better warranties and support |
Shadowclad has had a history of poor performance, both within the group and within the market. With highly publicised law suits against product performance this represents a consumer risk, both in claims or accusations of supplying inadequate product. Problems include glue failure, warping and cracking.
Similar looks can be achieved with James Hardie Axon panel.
Cedar is nice product to bring warmth to a building, but requires regular maintenance, generally needing recoating every two years. This may not be an issue on a single story home, however if it will require scaffolding the extra cost will be many thousands more, which can upset customers.
Dark stains perform better than dark paint due to lesser surface tension than a film-forming paint creates, however dark stains will fade quicker – requiring restaining in as low as two years.
As a rule we should make customers aware that in general a paint or stain with a Light Reflectance Value (LRV) of less than 40% should be used. Stains are not classified by LRV values, however a good rule of thumb is an equivalent paint colour LRV for guidance.
Paint manufacturers such as Resene offer a colour/LRV chart to assist: https://www.resene.co.nz/swatches/reflectance.htm
Modern pine weatherboard is considered to be formulated from less seasoned timbers, creating a lower quality product than the historic trusted perception (and many existing, old pine houses are often rotten or had significant remediations). Modern boards are also typically single primed for cost, with industry consensus being that a double priming is required.
This creates issues of significant shrinkage during summer months, leading to issues of paint coverage and eventually premature paint failing. The group has seen multiple issues of this.
Repeated expansion and contraction also creates warping and cracking of the board, creating significant issues.
The majority of pine weatherboard is from independent saw mills and the industry is littered with these manufacturers being uninterested or unable to warranty any significant claims, exposing the customer and franchise to increased risk. The ability of any supplier to honour a warranty is key and therefore the use of pine weatherboard is not allowed through the group.
James Hardie Linea Weatherboard should be used.
Change 27/10/2023
Naigara Timber weatherboard can be used as an alternative to Linea if required.
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Intent We are soon going to be assesing carbon content of our builds. It is known that fibre cement products require large amounts of carbon in there manufacture. Timber weatherboards will then be a more carbon effective alternative. |
Board and batten is a popular look, however historic precedence has shown that many installations can create significant customer issues.
Warping, splitting, cracking, dark colours and batten spacing all have a problematic history through the group. The vertical battens also make any warping extremely obvious to customers, creating perceptual issues of the cladding which results in complaints and remediations.
Board and batten should be avoided. Consideration to James Hardie Axon Panel or vertical Stria can be given.
The use of Fibre cement largely negates the issues faced by tradition methods of timber board and batten while allowing a much broader range of colours to be used
The Hardieflex Technical Specification allows the use of 7.5mm board with 75mm Weathergrooved H3 batten, or Axent Trim or the CLD batten (for a rough cut look). Use of Fibre Cement Batten will prove more durable if painting the system a dark colour.
A more ‘robust’ Board and batten system uses Easylap as the base sheet – at 9mm Easylap provides additional strength especially at the overhangs over the bottom plate. While this is not shown in the James Hardie EasyLap Technical Specification James Hardie have created a specific detail for this to ensure smooth processing with Council .
Strong risk of cracking or discolouration – should be avoided at all times.
Technically not a preferred supplier to the group, but product has good performance. Great for lower maintenance areas of a homes, for example second storey.
Product typically has a ‘state housing’ perception and the glossy finish isn’t for everyone.
Problems have been noted where customers have used barbeques or fire pits in close proximity to the cladding, causing warping or pitting. Similarly, NZ UV exposure levels have been questioned, however product does have good historic performance.
The Requirements
Not Permitted
Permitted
We have seen corrugated iron cladding being used in some areas. Sometimes this is used as a design feature or as a cheap cladding alternative. The product however is not with out issues and while it has a great history as a roofing material that situation is quite different. This has also been used to get around the dark colours restrictions it only transfers the issue and disregards the issues all dark claddings create
Further Information
BRANZ Issues and Repairs (Profiled Steel Claddings)
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The Intent We want to be sure our clients are advised of concerns with products that could create issues for them. A house that is hard to maintain and performs poorly is not a house that will lead to its owner referring us to their closest friend We also want to encourage the use of products that will fit with our brand and while these houses may look okay when they are shiny and new they can damage the brand if they start to prematurely deteriorate.We know our clients struggle with maintenance and this is made harder if we use products that are difficult to repair and look after |
PVC has strong international presence, being the default choice in many countries. The product has low maintenance and great thermal performance.
NZ solar conditions however create questionable longer term performance. Whilst NZ standards on PVC UV exposure are present, there remains a lack of long term performance precedence to lean on. Fading, pitting and becoming brittle remain concerns.
NZ preferred suppliers (APL) are moving in to this space and should always be utilised if the product is to be specified, however it is good practice to steer customers toward tried and trusted aluminium joinery where possible. If thermal performance of aluminium is a concern, consider thermally broken options.
Flashing details and council acceptance also need to be ensured if product specified.
Low maintenance, pre-finished option, however use should be avoided at ground floor level due to strong risk of damage or scratching. Customers can be informed of these problems, however when the home is sold on then typically issues come back around through new owners unaware of the issues. This therefore represents risk to us as a builder, not the customer.
Product is great for high level use to reduce maintenance requirements – although manufacturer maintenance guidelines should be confirmed.
Cladding can also be extremely expensive.
Without the use of cove products square stopping is necessary. This can create typical problems of cracking and the cutting in of two different paint finishes.
Precedence suggests that cove creates a much more satisfactory longer term performance and significantly reduces call back work for remediation.
Back Flashing required
Make joins away from midfloor junction. Strap and line if required
These are occasionally required by customers. It is important to note the additional maintenance of these ongoing – this should always be discussed with the lift manufacturer.
Care around tolerances and services required should be made. It is always important to check the drainage and ventilation requirements to the pit thoroughly.
Wall hung WC/Bidets should be avoided due to the increased risk of heavier loadings creating failure. Many products only rated to a conservative level and heavier populations’ means there is increased risk of weight limits being exceeded.
Similarly the in-wall nature of the cisterns creates significant problems of consequential damage should a leak occur, particularly if this is not easily noticeable.
Slimmer ‘back to wall’ toilet cisterns are available and should be specified in conjunction with floor standing units only.
Having baths and fittings with in a wetroom creates issues around draing water from behind these. Prevention of water sitting and breaking down mebrane can occur as weel as water entering between the baths and fittings
The use of tiled, walk in showers creates significantly more durability issues than pre-formed acrylic alternatives.
Typically specified for an aesthetic reason it is important to ensure the customer knows of the increased maintenance requirements of tiled showers. If the customer is planning to rent out the home they should be aware that acrylic systems represent a more robust detail.
Hybrids of tiles and shower trays can create a more robust solution, combining the benefits of tiled walls and an acrylic base.
As per notes above, however these are strongly recommended to avoid. The significantly increased consequence of failure means these are extremely risky to undertake.
It is important to make the customer aware of the increased risk at upstairs level, especially relevant given the maintenance requirements of bathrooms in the years to come. This would be absolutely the same for any competitor builder, regardless of what they claim – we are not disadvantaged by supplying this advice, we are a consultative sell.
A good system and solution is under investigation at present, using the appropriate industry bodies and professionals to provide the look at minimum risk to customers and businesses. This is a priority and will be updated accordingly. We recognise the commercial need and consumer taste preferences.
Some manufacturers such as Athena & Clearlite offer a hybrid shower tray/tile supply and install solution, warrantying the install themselves.
Three solutions for Tiled showers on upper stories are now approved
Newline Drifit
Atlantis
This system uses an acrylic base complete with upstands and waterstops. Use of waterproof tape between acrylic upstand and wall board is mandatory when used in a GJG Build.
The warranty has been specifically rewritten for GJ Gardners to allow this to be tranferred between owners unlike the residential warranty
Showerwell
This system uses a Manufactured base complete with upstands and waterstops. An acyrlic wall liner is trhen used to waterproof the wall
Showerwell is installed by the manufacturer
Often specified for light or aesthetics of a bathroom, however any horizontal sill surface around free flowing water can encourage the premature failure of waterproofing, creating significant consequential damage.
Additional complexities of routing pipework can also occur.
These should be avoided at al times.