Bamboo flooring is extremely susceptible to humidity and moisture vapour, causing expansion and warping of the floor. It is not suited to NZ conditions. Multiple failures like this seen, particularly where laid on a concrete slab.

Warranties are extremely limiting and put a large amount of responsibility on the customer which is unlikely to be followed through. Suppliers frequently stand behind onerous warranty terms.

A more robust hard flooring product should be specified. Consider preferred suppliers like Godfrey Hirst.

Dark colour absorb heat creating increased thermal expansion. Many products are incapable of handling dark colours outside of a specific light reflectance value (LRV). It is important to also ensure correct LRV values are specified. Paint manufacturers such as Resene offer a colour/LRV chart to assist: https://www.resene.co.nz/swatches/reflectance.htm

Some paints such as Resene Cool Colours suggest better performance, however this is still unlikely to be warrantied by the manufacturer causing problems should a claim materialise and therefore should still be avoided.

Whilst we recommend against dark colours, preferred supplier James Hardie do warrant their Scyon product range do allow darker colours, however customers should be informed that additional maintenance is likely required, for example dark colours fade much quicker and require repainting.

A cavity system is always required to ensure adequate venting away from the frame (note all builds should be cavity system anyway). Therefore James Hardie Scyon on a cavity is the only acceptable method of achievement.

James Hardie Scyon products include: Linea, Stria, Axon, Linea Oblique, Axent Trim

Our discussions with our clients should be directed at showing the benefits of using lighter colours. This discussion is made challenging if we use colours on our showhomes that go against the advice we providing. To support this discussion Showhomes must have paint colours selected with an LRV (Light Reflectance Value) of at least 40%.

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.

Key shortcomings of warranty

• 15 Year warranty as opposed to 25 year warranty of most cladding suppliers
• No warranty for cracking splitting and warping. Specifically excluded in warranty
• No cover for boards closer than 300mm from ground level. As the bottom board will generally be below this then this will be excluded. Not clear in warranty how this would affect vertical board
• Non transferable warranty

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.

CHH Currently facing two high profile lawsuits relating to watertight issues

• Adina Thorn Class Action
• Scoop - Leaky School Claim

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.

• Finish according to suppliers directions.
• Consider getting first coats by supplier at factory to protect during transportation.
• Consider maintenance at design stage. How difficult is it going to be to scaffold or paint? Ensure customer is aware of all maintenance costs.

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.

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

Board and Batten – HardieFlex

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.

Board and Batten – Easylap

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 .

Notes

• Because Easylap is a cladding system in its own right that can be installed complete with shiplap joints & corner flashings it provides the option to be flexible with the type, position or width of the battens used – this allows ‘random batten fixing etc. as they are purely an aesthetic feature and not part of the cladding system.

Images

• EasyLap Board and Batten - Vertical Join
• EasyLap Board and Batten - External Corner
• HardieFlex with Cedar Battens
• Easylap with CLD Battens

Strong risk of cracking or discolouration – should be avoided at all times.

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.

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.

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.

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.

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.

Two solutions for Tiled showers on upper stories are now approved

• 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.

Often specified for light or aesthetics of a bathroom, Keeping the sill height above 1800mm minimises the chances of water sitting on the sill, 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.

• Workmanship of these is critical and longer term performance can be questionable, therefore where possible customers should be steered towards moulded acrylic systems to keep overall integrity long term.
• Always use a full system methodology for simplicity and accountability.
• Keep any recess off an external wall to allow appropriate insulation. Consider the use of a double skin wall in this instance.

• Workmanship of these is critical and longer term performance can be questionable, therefore only preformed recesses whether tiled or prefinish should be used. Both Showerwell and Atlantis have options availible for this.
• Always use a full system methodology for simplicity and accountability.
• Keep any recess off an external wall to allow appropriate insulation. Consider the use of a double skin wall in this instance.

Avoid at all costs, risk of leaking too high. Long term performance will be poor.

For clients with accesiblilty requirements that must be met, fitting such as grabrails and framed seats are permitted, however the waterproofing details are to be supplied from the manufacturer/installer with the Building Consent.

Historic problematic performance of use near to free flowing water, for example showers. Water can migrate from shower leaving a close proximity vanity potentially standing in water. Over time this creates swelling of vanity unit and delamination/failure.

Where vanity is in a separate room/portion of the bathroom these can be specified. For close free flowing water proximity installation consider wall hung only.