FAQs

Is a Shotcrete Home structurally engineered?

With the lack of certification and quality control within the building industry, a major advantage that Shotcrete home has over others, apart from its own internal controls, is the independent quality assurance offered by professional Engineers.

In addition Engineers provide independent site inspections throughout the build.

Are Shotcrete Home walls cost effective?

Absolutely, due to Shotcrete home method of installation. Many things needed in other systems, just to make them work, are not required in Shotcrete home. Depending on design and by using a Shotcrete home certified builder, more often than not, the complete cost of the build may actually be less.

Why are Shotcrete Home walls so cost effective?

In a nut shell, the Shotcrete home patented building method. Shotcrete home use concrete, concrete is made locally, inexpensive and as a building material, does so much. Concrete is mother nature’s answer to mother nature. It will not burn, blow over, and fall over or anything else mother nature can throw at it. The Shotcrete home method uses it’s insulation as form work, which essentially gets two birds with one stone. The concrete is applied by shotcreteing, a time tested cost effective method of application used in swimming pools, tunnels and other wall systems. All this adds up to an incredibly fast, superior and cost effective building method.

Is Shotcrete Home a retaining wall?

Shotcrete home is a great retaining wall. Not only is it insulated, but the Shotcrete home concrete can be placed up to 300mm wide, completely waterproof and requires no construction joins for up to 12 meters.

What type of cladding is available?

Plastered and painted, brick, stone, weatherboard, panel and even tiled.

Is a Shotcrete Home just a plaster system?

No, a Shotcrete home is a continuously insulated structural concrete wall system that has a complete range of cladding systems that plaster is only one of.

How can the Shotcrete Home plastered walls be crack free?

Plaster cracks due to the various movements in the substrates that it is applied to. This movement is generally due to temperature changes. Each material, (substrate), in the wall will move at a different rate to that which it is next to, or connected to.  Joins in most substrates are filled with mortar, glue, sealant and sometimes nothing at all. These are all weak points, as they move independently to the surrounding substrate, putting a strain on the plaster and often causing it to crack.

Shotcrete home has no joins, it is continuous and is one substrate,-Concrete. Shotcrete home high strength, special mix concrete does not shrink like other concretes. Plaster is applied 90 days after shotcreteing, this does not stop the building process but allows the concrete to fully cure and settle. Thermal expansion seen in substrates and framing that cause plaster to crack are not seen in Shotcrete home concrete walls. Concrete due to its thermal mass has little to no thermal expansion at all.

Why does a Shotcrete Home walls not Leak?

With over 11 Billion dollars worth of damage in New Zealand due to homes leaking and causing major structural issues, the potential owner of a new home has to seriously consider whether they could fall into the same category by not choosing the right building system. The fact is, Concrete does not rot. Shotcrete home uses a High strength concrete mix that has a low water:cement ratio.

This Structural grade concrete, on its own, does not require any additional surface treatment to prevent water penetration. In addition to this, a crack free  plaster and paint system is applied to all Shotcrete home concrete wall finishes.

What is the best place for Thermal Mass?

The best place for thermal mass (concrete) is on the inside of the insulation. If the thermal mass is not insulated from the outside cold it is not effective and can become more a problem than a benefit, this is why it is vital that there is no thermal bridging (breaks) in the wall. Shotcrete home walls and floors are continuously insulated with no thermal bridging.

Thermal mass is best located where it receives direct sunlight (Radiant Heat), this is generally the floor and strategically placed concrete walls. Thermal mass floors and walls are also placed best in rooms where there is excessive convectional (air) heat gain.

What is a thermal break?

A thermal break is a material, which is part of the wall or floor where via heat can escape and cold can get in. Theses materials such as timber, steel and concrete are not insulators.

Concrete with its thermal mass properties needs insulation. Steel is a conductor, the opposite of an insulator. It is the reason why 80% floor heat loss is through the edge foundation perimeter. The steel in a concrete floor is connected to the foundation. This steel conducts the heat in the floor and rapidly transfers it to the cold foundation outside. This also explains why some underfloor heating systems are expensive to run, as the heating pipes are connected to this same conducting floor steel.

Timber is not an insulator. The average timber frame wall is 25% Timber and 75% insulation. If the insulation is R2.6, the True R-value of the entire wall is only R-2. All Shotcrete home walls are True R-values.

Is polystyrene the only available insulation?

No, the Shotcrete home patent and systems apply to any insulation; even a Shotcrete home straw bale home can be constructed.

Do the Shotcrete Home walls need to breath?

No. Walls needing to breath are just a nice way to say they need to dry out. Timber frame walls need to breathe because the timber constantly absorbs moisture and it needs to constantly dry out or it will rot, even if its treated, resulting in serious structural issues. This drying out process sucks the warm air out of the house, creating drafts and contributing up to 50% of heat loss. Just because a house is new, does not mean that it is warm! New Zealand houses are considered cold, damp and drafty, ask anyone who has lived in Europe or has emigrated from there. The Shotcrete home concrete wall does not rot, has no gaps, has high continuous insulation and is not only up to European standards, it surpasses them.

What’s the problem with cavities?

Cavities are an essential element in timber frame construction. They are design to allow water to get out. The problem, as logic dictates, is that if water can get out, then cold air and other undesirables can get in. Many cladding systems claim they have an insulation value; the material may have an insulating factor, but if it is used on a timber frame cavity system, then that same insulation means and does nothing, as the cold simply bypasses that insulation through where the water comes out. FACT: if water can get out – then cold air can get in!

Is timber a thermal break?

No. Timber may be a break, but it’s certainly not thermal. For timber to be thermal it must have thermal properties, which it does not. Timber is not an insulator. In fact in timber frame housing, timber is the break (cold point) in a thermal wall!

Does a Shotcrete Home have a plaster over polystyrene system?

No.

What makes Shotcrete Home plaster different?

Plaster is only as good as what you plaster on to. The Shotcrete home structural wall requires no joints up to twelve meters long. It is of the same material (substrate), concrete, and concrete unlike other materials has virtually no thermal expansion. Shotcrete home has a ninety day stand-down period before plaster is applied. This allows the building to settle, it is a luxury that other systems do not have. Other systems need to plaster early to protect the substrate or water proof the building,- plaster to early and cracks will appear!

How good the substrate is and how long will it last is of prime importance, unlike the others, concrete actually gets stronger as it ages. The older the house, the better it becomes, how many other systems can say that?

What makes a Shotcrete Home insulation different?

Shotcrete home insulation is continuous and is not interrupted by a structural element. The Shotcrete home system has two separate walls one for insulation and the other for structural integrity. As wet concrete dries it laminates with the polystyrene and they essentially become one. Shotcrete home recognises that the materials used in a structural element (Concrete, Steel, Timber) are not insulators and cause serious thermal bridging. This is why Shotcrete home separates the two instead of trying to jamb them together. Having a separate structural wall makes adding additional insulation an easy and cost effective procedure.

What makes a Shotcrete Home thermal mass different?

The thermal mass in the Shotcrete home systems is actually insulated, not only is it highly insulated, it is continuous.

What makes the Shotcrete Home concrete wall different?

Tilt slab concrete walls require gaps at each corner. These gaps are filled with sealant, which will need replacing and remain visible after plastering, or filled, creating a vertical cold joint. As a structural lintel, it is restrictive and may require costly steel beams.

Concrete block requires a wider wall, taking up valuable insulation space. As a structural lintel, it is also restrictive and may require costly steel beams. Plaster is applied over joins and two separate substrates.