An Introduction to Structural Insulated Panel Kit Homes
How are Structural Insulated Panel Kit Homes produced?
As the name suggests each panel consists of a central core of rigid foam insulation, such as EPS (expanded polystyrene foam), usually 75mm or 100mm thick, sandwiched between two outer layers of structural building board.
These outer layers can be “OSB” oriented strand board, “MGO” magnesium oxide board or even flat colorbond sheet metal.
The three components that make up the panel are bonded together with a high strength construction adhesive in a clamping device.
The structural strength of these modular insulated panels as a building material is referenced by Wikipedia in the following two sentences.
SIPs share the same structural properties as an I-beam or I-column. The rigid insulation core of the SIP acts as a web, while the sheathing fulfils the function of the flanges.
Are Structural Insulated Panel Kit Homes a relatively new building innovation, that is still largely unproven and untested in the real world?
Definitely not, the earliest examples of using SIPS was introduced in America in the 1930s and a small SIPS home built in 1937 and was used by the University of Wisconsin as a day care centre, until it was removed in 1998 to make way for a new school building.
In countries where Sip homes have been popular since the 1970s, they have withstood hurricane winds and earthquakes with amazing integrity, owing to their superior transverse load resistance.
The design of the structural insulated panel building system has continued to develop, driven by the push toward reducing greenhouse gas emissions, and developing more energy efficient and sustainable housing.
One part of the reason for the popularity of structural insulated panel building system kits, is that thermal efficiency and comfort are built in at the manufacturing workshop, and delivered to site as a strong, lightweight prefabricated kit, that results in a neater site, faster project completion, minimal wastage, and labour reduction.
The prefabricated structural insulated panel kit homes can save many hours of construction time on site with 3 simple steps to complete a wall stand.
- Place bottom track in position on slab or floor.
- Stand the structural insulated panel walls
- Put top plate channel in place
The wall is then complete ready to fix joins & render on the outside and paint on the inside.
Then consider the different stages a builder or owner builder must complete to construct a more traditional timber or steel stud frame brick veneer wall with fibreglass batts as insulation.
1. Fabricate and stand stud plate and noggin timber or steel wall frames.
2. Then place insulation Batts in between wall studs and noggins.
3. Place a bracing ply on the external of the timber wall frames.
4. Next externally is a waterproof breather membrane
5. Then lay a single layer brick wall with brick ties back to the timber frame.
6. Then on the internal attach a sisalation vapour control layer to the frames.
7. Then finally the internal plasterboard lining fitted ready to be plastered and painted.
One more important aspect of working with prefabricated structural insulated panel kit homes is that all components are straight and true and you don’t have to struggle with green and crooked timber frames.
Inset picture was taken looking down at the top plate along the top of a long wall of a home under construction.
What makes structural insulated panel construction more energy efficient?
With heating and cooling responsible for up to Forty percent of household energy consumption, and record extremes of temperature becoming more common each year, it just makes good sense to build a well designed, energy efficient home that can maintain more constant internal temperatures, and requires very little energy to remain comfortable, and not have to rely so much on mechanical heating and cooling.
Structural insulated panel design that combines the structural and insulation components as one, has been tested to be 3 to 5 times more airtight than standard traditional timber framed homes with fibreglass insulation.
Inadequate installation or even missing batts due to the difficulty of fitting within the timber stud frame, can result in temperature change at every stud location. Testing of whole wall performance has indicated that air loss in stud wall construction can reduce R Values by as much as 30% of the wall area.
On the other hand, the structural insulated panel walls with rigid foam insulation performed at 97% of original stated R-value only losing 3% to seams, nail holes etc.
Being more airtight provides an added benefit of being very quiet inside, so it’s not uncommon for people to comment that you can feel and hear the difference, in an insulated panel home.
Air infiltration poses more problems than just higher energy bills, as air that passes through fibreglass insulation often carries moisture, which can cause hidden mould growth in wall cavities, and poor indoor air quality that can lead to health problems for occupants.
What about the quality of the finish in a structural insulated panel kit home?
This is a very common question as there has been a stigma about kit homes still looking like the cheaper versions of kit homes from many years past, even when fully completed by a good builder.
The kit homes of today are a far cry from that, and some have evolved to the degree that you really can not see a difference in the completed product either inside or out between a kit home and a master built home built onsite from scratch.
To reinforce that, take a look at one of the more recent innovations in structural insulated panel kit homes at Panelock Building Solutions.
These, structural insulated panel kit homes have a rendered finish external, and a smooth line painted finish internal, similar to plasterboard but with many added benefits.
These extra benefits include being more durable and difficult to damage, which makes them ideal for investment rental properties, it is also water resistant, insect resistant, mould resistant and the extra safety of being almost impossible to burn.
Panelock’s designs feature the use of one of the greenest building products on the planet as the internal and external sheaths or linings, Mgo board or magnesium oxide board making 100mm thick wall panels with an internal core of EPS.
Structural insulated panel kit homes look like any other home both inside and out , the main difference is in the performance.
You won’t get this kind of Energy Efficiency with sustainability, durability and comfort in any other style of home.
Are structural insulated panel kit homes actually sustainable?
Firstly, the rigid foam insulation or EPS or expanded polystyrene
- Sustainability during Manufacture
The EPS manufacturing process unlike many synthetic materials does not involved the use of ozone-layer-depleting CFCs and HCFCs, nor are there harmful materials present in the finished product.
- In order to expand polystyrene, steam is applied to tiny grains of styrene that contain a minute amount of pentane. The expanded beads are then molded into a shape or a large block which is then sliced into boards. The minuscule amount of pentane gas used in the process has no known effect on the upper ozone layer.
- No residual solid waste is generated during its manufacture as EPS is uniquely recyclable – all manufacturing waste can be completely reprocessed in the production process.
- EPS is an excellent example of an efficient use of a natural resource as the transformation process uses relatively little energy.
- EPS is inert and non-toxic and acts as a stabiliser when sent to landfill. EPS aerates the soil, encouraging plant growth on reclaimed sites. While EPS does not degrade, it will not leach any substances into the ground water, nor will it form methane gas (a major contributor to the depletion of the ozone layer).
- EPS products used in the building and construction industry have a very long effective lifespan because of their durability, so disposal of the product is minimised.
- Expanded Polystyrene (EPS) is 100% recyclable.
Over the past decade, EPSA has established the REPSA National Collection Network to facilitate EPS recycling in Australia.
SUSTAINABILITY OF THE PRODUCT IN USE
EPS brings considerable energy and resource-saving benefits making it a smart and sustainable choice for both packaging and building/construction applications.
The manufacture of EPS uses less than 0.1% of global crude oil as a feedstock however it can deliver up to 200 times its own resource in thermal energy savings.
The following characteristics of EPS enable it to minimise both environmental impacts and costs:
EPS packaging achieves significant transport savings compared to other packaging materials due to its light weight resulting in lower fuel consumption.
Its exceptional cushioning and thermal properties result in lower damage rates and maintain a secure cold chain for temperature sensitive products.
EPS is one of the lightest of all construction materials allowing ease of handling and faster construction times. Its outstanding thermal insulation properties and durability ensure performance throughout the full lifetime of the building/construction application in which it is used.
EPS is also recyclable at many stages throughout its life cycle.
Information on the sustainability of EPS by the EPSA Organisation of Australia.
Sustainability of Mgo board
The Mgo or Magnesium Oxide Board cladding on each side of the panel.
1 – Recycled (RC): Newly manufactured Magnesium oxide wall boards use 30%recycled material.
- – Non Toxic (NT): Magnesium oxide wall boards are manufactured from 100% natural material; it does not produce toxic emissions that affect the building indoor air quality.
- Building Operations: – Energy Efficiency (EE): Using Magnesium Oxide wall boards for external building envelope saves heating and cooling energy as the wall boards of 10Mm thickness has thermal insulation R Value of 219 Watt/Mt Kelvin.
- Waste Management: – Biodegradable (B): Magnesium oxide wall boards contain 100% natural material, so the demolished product produces a fully biodegradable natural material.
- – Recyclable (R): Demolished Magnesium wallboards produces Magnesium oxide powder which can be used in either the manufacturing process of new boards or in many other products that use magnesium oxide as one of its components.
This information on the sustainability is from the journal of applied sciences research number 2024Civil & Architectural Engineering Department, National Research Center, Dokki, Giza, Egypt.
Author : Col Watt
Panelock Building Solutions
Sustainable Insulated Panel Construction
Email : firstname.lastname@example.org
Website : panelockbuildingsolutions.com.au