Building Code changes to E3 and our solution to specifying wood flooring

Building Code changes to E3 and our solution to specifying wood flooring

Advice | October 11, 2021

This article provides information around the change to E3/AS1 and gives guidance on gaining compliance and putting forward and alternative solution for wood flooring in spaces with sanitary fixtures and appliances.

WHAT HAS CHANGED?  

From 5th of November 2021, wood flooring when being specified in kitchens, bathrooms, toilets, and laundries is to be presented to council as an alternative solution under E3/AS1. It is required to demonstrate to the building consent authority that the floor surface is sealed with a suitable, durable coating (such as Polyurethane) and that the perimeter and joins are sealed in all areas which have sanitary fixtures or appliances.  

To assist specifiers with this change we have updated our Forté Timber Overlay System Installation Manual to adhere with the E3 changes. Over the coming weeks our team will be meeting with Architects, designers, builders, and our approved installers to implement the changes and ensure we have the support in place to manage the change. Going forward, when specifying and submitting timber flooring to council, you will need to include the Forté Timber Overlay System Product Technical Statement (PTS).

What are the requirements FOR E3/AS1

Requirements for the surfaces used in areas with sanitary fixtures or appliances are:

1. Impervious
2. Easily cleaned
3. Constructed in a way that prevents watersplash from penetrating behind linings or into concealed spaces.   

OUR SOLUTION FOR MEETING REQUIREMENTS 

1. Impervious 

All Forté Engineered timber floors have high performing polyurethane finishes. When glued down using the relevant Forté installation guides they will satisfy the impervious requirement due to the below points.  

  • All Forté floors come prefinished with a high-quality polyurethane finish which have a build of coating on top of the surface. They act as a sheet over the floor which protects it from moisture. All quality brands will have several coats of water-based polyurethane.  
  • Ensure the coating of the flooring is a high quality and durable brand of Polyurethane such as Swedish brand Bona®.  
  • All Forté products are put through and pass our water resistance test which requires no water to penetrate the surface within 12 hours, and therefore satisfy the impervious clause. 
  • Forté Timber Floors have a history of being used in areas with sanitary fixtures and appliances for over 10 years and demonstrate imperviousness.  

2. Easily Cleaned 

  • Timber flooring with polyurethane finishes are easily cleaned with a vacuum cleaner and mop and are comparable in cleaning methods to the flooring materials which fall under the Acceptable solution (Vinyl/Tiles/Concrete). 
  • The cleaning methods and long-term care for our timber floors is outlined in our Forté Timber Flooring Care book.  

3. Constructed in a way that prevents water splash from penetrating behind linings or into concealed spaces.

Further instructions or guidance on the below points can be found in the updated Forté Glue Down Flooring Installation Guide for Professionals – Engineered Plank

  • We have designed a system which ensures the entire surface is completely sealed in all joints as well as around the perimeter and around any fixed items (only needs to be within 1.5m from sanitary fixings). This means the flooring is constructed in a way that prevents water splash from penetrating behind the linings or into concealed spaces.  
  • The gaps between all planks are to be sealed using a waterproof adhesive. We use a clear silicone on the tongue and groove joints which seal the gap and prevent the penetration of moisture.  
  • The entire perimeter of the flooring as well as any fixed items of the room must be sealed with a paintable silicone (caulking), which prevents water from penetrating between the connecting profile.  
  • We only recommend the glue down method which completely minimizes the natural movement of timber and eliminates the possibility of gaps opening (provided the ‘Ambient Conditions’ guidelines are followed as per the guidelines references above).  

Floor areas covered under E3/AS1 

As per NZBC Clause E3, the areas are defined as floor surfaces of any space containing sanitary fixtures or sanitary appliances such as kitchens, bathrooms, laundries and toilet facilities. While kitchens are the most popular area for installing timber flooring, the upcoming change to the amendment will see flooring surfaces under the Acceptable solution limited to common linings and finishes such as ceramic tiles, sealed or polished concrete floors (slab on grade) and waterproof sheet material with sealed joints. It is important to note that the change in amendment will have no effect on timber flooring being installed in entrances, hallways, dining and living areas. 

Why were the changes implemented? 

The changes to E3/AS1 were made to ensure the Acceptable Solution (E3/AS1) better aligns with the existing requirements of the Building Code. Section E3.3.3 of the amendment states “Floor surfaces of any space containing sanitary fixtures or sanitary appliances must be impervious and easily cleaned.”  

Timber flooring not likely to meet the new requirements 

Oxidative and Hardwax Oiled Flooring finishes DO NOT have a build of coating on top of the timber like Polyurethane does, and therefore will unlikely satisfy the requirements under Clause E3. 

The floating installation method (which is commonly used with timber flooring) is unlikely to satisfy the requirement of being ‘Constructed in a way that prevents water splash from penetrating behind linings or into concealed spaces’ as it allows the flooring to freely move and expand/contract. This means that it is possible for gaps to appear and therefore it is unlikely to satisfy the requirements under Clause E3. 

Summary of changes to E3/AS1 

This article has been written based on the information that the MBIE and BRANZ have provided to date regarding the E3/AS1 amendment affecting the use of wood flooring in spaces with sanitary fixtures and appliances. We have combined this information with our experience in wood flooring to give guidance on how to gain compliance and put forward an alternative solution that we feel will meet these requirements.  

Engineered wood flooring has been a popular flooring type in kitchen and dining areas as well as bathrooms and laundries for decades. Most of our projects include kitchen areas, not only due to the durability, but also the appealing aesthetics it brings to an interior. 

This change made in November 2020 to the NZBC E3/AS1 amendment will see timber and timber-based products removed as an acceptable flooring solution from 5 November 2021. However, this is not to say that timber flooring cannot be used in these areas going forward, instead you will need to provide an alternative solution that proves the product and installation method complies with NZBC requirements. 

What this means when specifying timber flooring 

When specifying timber flooring the following factors need to be considered: 

  • Specify timber products with a water-based Lacquer or Polyurethane as opposed to oil finishes (hardwax oil goes into the timber resulting in no moisture protection) 
  • Glue down installation only (floating floors cannot seal the perimeter as it needs space to expand/contract – does not meet requirements). 
  • Include the Forté Timber Overlay System Product Technical Statement (PTS) when specifying.  
  • Ensure you submit the updated Forté Glue Down Flooring Installation Guide for Professionals – Engineered Plank, which references areas with sanitary fixtures and appliances, when specifying.  

Forte is currently working on a codemark which will streamline the specification process, in the meantime please use the information in this article as guidance to gaining compliance and putting forward an alternative solution. If you need more information or assistance, please reach out to one of our Territory Managers who can help walk you through the specification.  

Auckland 
Aaron Wiltshire
[email protected]
021 894 393



Upper North / Central North
Gratton McCallum
[email protected]
021 116 2568




Lower North / Upper South
Courtney Wilson
[email protected]
021 808 533




Lower South
Larissa Lynch
[email protected]
021 805 058






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