All Stellaria products FAQs. 

NOTE – choose your concerned product from drop-down (on mobile)/ section (on desktop) menu below.

General Questions
Who is Stellaria?

Stellaria NZ Ltd is the NZ distributor for all Wienerberger, Internorm, BOEN and MST Marbles products.

Who is Wienerberger?

Wienerberger, Europe is one of Europe’s largest multinationals producing clay construction blocks, clay roofing tiles, clay facing bricks, clay facing tiles and clay pavers & piping systems. Founded in 1819, Wienerberger was publicly listed in 1901. Wienerberger now exports worldwide with 202 plants in 30 countries and is the global market leader for clay facing bricks, roof tiles and pavers. Wienerberger stands for high-quality natural clay products, which are marketed under the brands KORAMIC, POROTHERM, TERCA, PENTER and ARGETON. Wienerberger produces roof, wall, façade and paving from pure natural clay. Brick is one of the oldest building materials in history and therefore sets a perfect example for the modern concept of sustainable products. Wienerberger is exemplary for its environmental & business ethics, diverse designs and creations, energy-efficient construction and durable quality, holding their value for a very long time. Building with Wienerberger therefore, represents an economically and ecologically sound investment for the future.

Terca Bricks
How much are Terca bricks per m2?

On average, our bricks start at approximately $62 per m2. However, consider that a cladding job using a longer brick, say at 500mm long, will be more expensive per unit, but will require fewer bricks overall and will be quicker to lay.

How many Terca bricks are there to choose from?

We have over 500 unique bricks to choose from in 2019 – download our Terca Brick Full Range 2019 brochure on the Terca Brick page to see all of our bricks.

What brick slips are available?

Any of the full bricks available in our Terca Brick Full Range 2019 catalogue, found on the main Terca brick page, can be cut into brick slips. The correct way of manufacturing brick slips is to cut them from the whole brick. Two brick slips are created from every brick. Commercially and mass-produced brick slips are kiln-fired from thin profiled clay sections with the result that they look nothing like the original brick, are often out of shape, and fragile.

How much does it cost to clad with brick?

It depends on the brick chosen. Our bricks vary from 80c to $8.00 each. Please let us know what brick you’re interested in, and we’ll send you dimensions and price accordingly.

How do I order Terca bricks?

Have a look at our full range by downloading the Terca Brick Full Range 2019 brochure on the Terca brick page and email us with the brick you are looking for at info@stellaria.co.nz.

How long will it take for my bricks to arrive?

Allow approximately 10 – 12 weeks for manufacture, sea freight, and delivery.

How long do the bricks take to be manufactured?

If manufacturing is required because your chosen brick(s) are not in stock in Belgium, allow 4 – 6 weeks.

Do the bricks need to be sealed?

No.

Do the bricks need to chemically washed?

No.

What rebate should be allowed for in the floor slab when using brides?

Allow 100mm for the brick, and 50 mm for the cavity.

What are tumbled bricks?

Tumbled bricks are ‘tumbled’ in a large drum containing stone chips & sand to create an old and aged look.

What is a ‘bagged’ finish?

A bagged finish is a very thin, watery plaster applied over the bricks to give an aged and stressed look without losing the definition of the individual bricks.

Does ‘salting’ occur on Stellaria/Wienerberger bricks?

Yes – Salting (commonly called efflorescence) occurs naturally on all natural clay (not concrete) bricks, but it comes mostly out of the mortar, and not the bricks themselves.

How do I get rid of salting?

Generally, salting will naturally stop with exposure to weather and rain after around 6 – 12 months on its own, depending on brick thickness and size, and exposure to the weather. You can wash your brick facade if you wish, with a soft brush and clean water, but know that your brick will stop salting after around 6 – 12 months naturally, so there’s no need to worry about it. We do not recommend water blasting your brickwork as this may cause damage to the surface of the brick.

Do the bricks get mouldy?

Any brick can – in areas with excessive moisture, inadequate ventilation, or a significant lack of sunlight or air movement. Bricks are a porous, natural product. Don’t worry – mould has absolutely no effect on the structural integrity/strength of the brick itself as they are a natural clay brick that is 100% organic and inert.

What detailing can be formed with the bricks?

With the standard 100 series Terca brick, any positive or negative detailing can be created. This is the limitation with commercial, mass-produced 70 series bricks. If 70 series bricks are laid out of alignment, then they may no longer comply with the NZ building code.

Are brick slips cheaper than full bricks?

No. They’re exactly the same price, because of the need to maintain quality and cut them from the ‘parent’ brick.

Can I blend Terca bricks?

Yes. Any bricks can be blended, just ensure that the bricks are all the same length, height and depth.

What blended bricks are already available?

Refer to the 2019 catalogue of blended brick series under brochures on the Terca brick main page.

What dimensions are Terca bricks available in?

Our Full Range 2019 Terca brick catalogue available on the main Terca brick page has all of the sizes that Terca bricks are available in. Under each swatch in the brochure are the sizes that particular brick is available in. Generally, for most of our bricks, they range from 188 x 88 x 48 (mm) to 215 x 102 x 65 (mm).

What is a 'rustical'/'rustic' brick?

Rustic bricks take on a whole, recycled, traditional look. They appear uneven in texture, form and colour, to provide an aged, classic look, which is usually characterised in 100+ year-old buildings.

Do I have to pay for samples?

No.

How do I maintain my brick cladding?

No maintenance is needed – that is the essence of brick cladding.

What is the difference between mechanical & hand-made soft mud bricks?

Mechanical bricks are machine wire-cut bricks with very straight, crisp, sharp edges. They tend to be used in designs that are more ‘industrialised’, modernistic projects, with clean and fine lines. On the other hand, handmade bricks have a more soft, natural, aged appearance, where a softer and more natural look is wanted.

How do I fix brick slips to my substrate?

You have many options with numerous, elastomeric cement-based adhesives that can be used to fix brick slips to cement-based substrates. (Sika, Ardex, Mape, etc.). We recommend only cement-based substrates, not timber-based substrates. If you’d like more information, contact us directly.

What brick ties do I need?

We always recommend Mason’s brick ties. The higher the level of the brick facade, the more brick ties required per m2.

What different mortaring techniques can I use?

There is a mortar colour to match every brick, and the colour of mortar joint will depend on the design of the brick facade. So bagged brick will give you the aged look; raked joints will give you individual definition of every brick; flush mortar joints will give you a more monolithic soft look to the wall.

What guarantee do you have for Terca bricks?

Every Terca brick we offer has a D.O.P. (Declaration Of Performance). They’re a kiln-fired clay product and as a result they have a durability well in excess of any other cladding system. However, bear in mind that they will only be as good as the substrate they are fixed to.

What is the eco brick?

Eco bricks are a more cost-effective, slim-line brick meeting the market for minimum-thickness veneer bricks. However, they lack the thickness for any significant detailing.

What is the Iluzo brick?

This brick has the mortar laid to the centre of the brick which creates a ‘dry-stone’ effect to the wall cladding. Looks like stone but is clay brick.

 

Do the bricks offer any thermal capability?

Any brick veneer only offers the advantage of solar gain if there is no insulation between the brick and the built environment. In other words, no room will benefit from solar gain from brick veneer with timber frame where there is a layer of insulation between the brick and the room.

Are Terca bricks fireproof?

Yes. They’re a kiln-fired product with an A-rating in fire resistance, which is the highest possible rating.

What is a soft mud, hand-thrown brick?

Soft mud bricks (or stock bricks) are produced using a similar methodology to handmade bricks but using a machine.

What type of kiln are the Terca bricks fired in?

These are 24-hour kilns that fire the clay bricks to 1200 degrees Celsius.

How much waste do I need to allow for?

We usually recommend maximum up to 5% as the bricks are of high quality and breakages will generally never occur during transit from Belgium.

What if the bricks arrive broken & damaged?

This is extremely rare, if ever; they never have to date. But if this is the case, our marine cargo insurance will cover any breakages.

Where are the bricks made/manufactured?

Mostly Belgium, but occasionally France & the Netherlands.

Are the bricks compliant with the NZ building code?

Yes.

What certification do Terca bricks have to be installed in NZ?

Every brick comes with a technical producer’s statement which cross-references all of the NZ/Australian building code with European building code requirements. European building code requirements far exceed NZ and Australian building code standards.

What's the best colour of mortar to use?

It depends on the colour of the brick you’ve chosen and the final look you’re after. If you want to highlight the individual bricks, use a contrasting colour. If you want to create a quieter, more monolithic effect, choose a matching colour to the brick. Again, contact us directly for more advice, we’d love to help you out.

Do Wienerberger bricks meet Declaration of Performance?

Yes. Every single one of our bricks has its own Declaration of Performance (DoP).

What installation guide does my brick layer need to have?

Standard clay brick installation as per NZBC & NZS.

What type of mortar do I need to use?

We recommend EzyMix bagged mortar colour options, which is a specific brick veneer structural mortar, with around 9 different colours. You can look at mortar colours here. Alternatively, standard masonry mortar is readily available, which is just a grey cement colour. If you’re unsure, contact us directly and we’ll answer your questions.

Where can I see other Terca brick projects in NZ?

We have some of our Terca projects on our Projects page, which you can find in the main menu.

What's the best colour of mortar to use?

It depends on the colour of the brick you’ve chosen and the final look you’re after. If you want to highlight the individual bricks, use a contrasting colour. If you want to create a quieter, more monolithic effect, choose a matching colour to the brick. Again, contact us directly for more advice – we’d love to help you out.

What thickness of mortar should my quantity surveyor allow for?

10mm.

What is random bond?

Random bond is a pattern where the vertical joints have no regularity between the courses.

What does wild bond mean?

This means the Terca bricks will be deliberately sized and divided into 3rds and 1/2s to create a random look in each course. This creates a cobbled, authentically traditional appearance.

Why would I consider different styles of laying?

To create a unique and standout look for your brick facade.

What laying styles can I do with my brick?

Stretcher, English, Flemish, English Garden, Stack, and Wild bond. Read more about these different styles here on Wienerberger’s page. The choice for personalisation and styling is awesome.

Porotherm
What is Porotherm?

Porotherm is a natural fired, solid clay construction block. It is available in a range of sizes, complete with accessory blocks (Lintels and Portals) design-engineered in accordance with the NZ building code requirements for each project and seismic region. Solid clay construction now forms up to 80% of the building material choice throughout Europe. Clay and lime have been used for hundreds of years and is now used extensively throughout the world.

Is Porotherm suitable for seismic zones?

Clay construction is design-engineered to be twice as strong as conventional construction methods. POROTHERM, in it’s current form, has been used extensively throughout Europe for the over 50 years and is now used worldwide in many high seismic zones such as Russia, China and Europe. Rigorous shake table testing documentation is available to show the extent of tests carried out by Wienerberger Engineers, meeting the highest Euro standards. This construction method is extremely earthquake resistant.

What is the acoustic value of Porotherm?

The acoustic rating for R25 is Rw + C 42. LR42Th+ is Rw + C 44.

Is Porotherm waterproof?

Due to the thermal matrix design of the clay block most commonly used in NZ, R25Th+ at 250mm wide and kiln fired at temperatures of 1200c, water penetration is minimal. A breathable plaster system being waterproof and organic with mineral paint exterior finish is applied to meet E2 requirement.

Does Porotherm need a Flashing System?

No.

How are the fixings attached to the walls?

Standard masonry fixings or Hilti Screws available in NZ.

How is the plumbing piping & electrical cabling installed?

Chases are cut in the walls at a depth of 30mm. This is easily and quickly achieved by a builder, blocklayer, plumber or electrician using a double saw chase cutter with a vacuum.

How many blocks do I need per sq/m?

A standard 250 Th+ Porotherm block requires 8 blocks per m2. By comparison, standard concrete blocks require 12.5 blocks per m2.

What is the speed of construction - how many sq/m per man hour to lay?

Porotherm is 4 times faster to lay than traditional concrete building methods being a confined masonry system. The steel & concrete is only required, depending on the engineering in the lintels over the openings and the portals installed up to 5m increments along the wall. This has a significant impact on the end cost to build. Labour cost is the largest component of costs to any construction company or builder. Porotherm significantly reduces this.

What is the comparative cost to timber frame and concrete block?

You can find a wall comparison chart to show the comparative costs on our technical information page. A finished Porotherm wall is comparative to a high-end 140 timber frame wall with brick veneer cladding.

What is the design and/or life expectancy of Porotherm?

The design life of Porotherm is 150 years. The life expectancy of the clay block is many generations.

Does it have a guarantee or warranty?

Porotherm Clay blocks have a guarantee of 100 years. Installers are certified by Stellaria NZ.

Is Porotherm eco-friendly and sustainable?

Yes, absolutely. Totally natural clay construction. The Wienerberger sustainability story is at the heart of all their operations. To offset the carbon footprint required to transport from Europe to NZ, Stellaria offers 5 native or specimen trees (of your choice) to everyone building in Porotherm. We believe this gives something back to the environment the only element Stellaria NZ takes from the environment – the cost to ship it here!

What fire-proofing system is required?

None. Porotherm 250 Th+ has a F.R.R of 3 hours minimum.

What green ratings or certifications does Porotherm have?

DECLARE accreditation.
Sentinel-Haus Institut, the European centre for healthy building skills.
EMISSIONS DANS L’AIR INTERIEUR – Volatile Substances in Indoor Air.
AVEC LA TERRE CUITE means with clay, No Development of Mould.
ENVIRONNEMENTALE ET SANITAIRE is a Health Declaration.
NATUREPLUS – Respect for Saving Non-Renewable Resources.
QUALITEL – Acoustics & Thermal certificate Lower Energy & Maintenance.
AFNOR NF – characteristics certified by the French NF norm for clay blocks.
EXCELL ZONE VERTE – Green Certificate.

What cladding or plaster system can I use?

A lime-based plaster system is highly recommended to retain breathability of the block. Any cladding system can be used on Porotherm.