This article consists of all of the research I have done on the steel aspect of the steel kit homes. I’ve aimed to fill it with as much information with what you need to know when building with steel and why we chose steel for Our Kit Home build. I’ve put some headings to help with navigation
Steel Framing Components
1. Structural steel beams and columns
2. Steel studs for wall framing
3. Steel roof trusses
4. Steel lintels (for windows and door openings)
Frame Size: 70 mm or 90 mm?
When going to the steel frame manufactures there is two main options for the stud size, 70 mm or 90 mm of the wall frames. The stud size refers to the width of the wall frame also sometimes called the “stud wall”. Here is a quick definition for those who need it.
Defintiion: A wall frame is the structural framework consisting of vertical studs and horizontal plates that forms the skeleton of a wall in a building. It provides support for the wall’s surface materials, such as drywall or siding.
The two main options to pick is 70 mm and 90 mm.
I went with the 90 mm, the two main reason for this was
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- The Look- but comparing other owner builder houses and around, some looked a bit amateur from the outside. It is really important to me that the house looks good from the outside and as such I have prioritised architectural cladding. I have realised the 90 mm houses look a lot better, must be the larger distance between the walls, but this is not something you can change once it is installed or upgraded later, so to me was essential to get right from the start.
- The Functionality – the 90 mm vs 70 mm frame sizes allow for more space for insulation to be packed as there is that extra 20 mm of space. As our house is quite large and we are building in a climate that has large shifts in temperate, and is very cold in winter, want to eliminate the heating and cooling costs, this is around our semi passive design features.
Thermal Bridging- What Should I Use?
When steel frames get mentioned it is inevitable that thermal bridging gets brought up, I will try to cover the subject of what is thermal bridging? What do you need to know? And how do you build in a thermal break?
What is Thermal Bridging?
Thermal bridging is in its name- thermal- as in temperature and bridge as in a path. A thermal bridge is when a pathway is created within a building structure allowing heat to flow more easily than through the surrounding insulation. This means the heat will find a shortcut out of the building so will lose heat more rapidly, or gain heat more rapidly depending on the outside environment. This results in localised heat gain or loss, reducing the overall energy efficiency of your building, costing you more to heat and cool your house.
How to Build to Avoid Thermal Bridging
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- Thermal Breaks: Incorporating thermal breaks within the steel frame structure was another important step. These breaks are insulating materials that interrupt the conductive path of the steel, reducing heat transfer and energy loss.
- Effective Insulation: Proper insulation is crucial in minimizing thermal bridging. I used high-quality insulation materials that were carefully installed to create a thermal barrier between the interior and exterior of the home. This helped to maintain comfortable indoor temperatures year-round.
- Energy-Efficient Windows and Doors: I selected energy-efficient windows and doors designed to minimize heat loss. Double or triple glazing and low-emissivity coatings played a significant role in preventing thermal bridging at these critical points.
- I am currently looking into these James Hardie strips, as they look easy to apply, will see if the budget allows as we do have a very large house https://www.jameshardie.com.au/productrange/categories/pre-cladding/hardiebreak
Thermal Break- Some Options
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- Thermal Break Inserts: These are pre-fabricated inserts made of insulating materials such as rigid foam or fiberglass. They are designed to fit between steel components, creating a barrier to heat transfer.
- Thermal Break Coatings: Specialized coatings or paints with insulating properties can be applied to the surface of steel elements. These coatings create a thermal barrier that reduces heat flow.
- Plastic or Composite Shims: Thin plastic or composite shims can be inserted between steel components during construction. They provide a thermal break while maintaining structural integrity.
- Fiberglass or Foam Tape: Narrow strips of fiberglass or foam tape can be applied to the contact points between steel components to create a thermal break.
- Thermal Break Gaskets: Gaskets made of insulating materials can be used between connections of steel elements. They are often employed in curtain wall systems and window frames to reduce heat transfer.
- Thermal Break Insulation Boards: These are rigid insulation boards designed for use in steel-framed structures. They are placed between steel elements to create a thermal break while providing insulation.
- Polyurethane Foam Spray: Spray polyurethane foam can be applied to specific areas where thermal bridging is a concern. It adheres to the steel and provides both insulation and a thermal break.
- PVC or Composite Spacers: These are commonly used in curtain wall systems. They separate the internal and external framing components, reducing heat transfer.
- Rubber or Neoprene Pads: Rubber or neoprene pads can be used as thermal breaks between steel beams and concrete foundations, preventing direct heat conduction.
- Thermal Break Windows and Doors: In fenestration systems, thermal break technology is used to create insulating barriers within window and door frames. This minimizes heat transfer through these openings.
- Insulated Cladding Systems: Some cladding systems are designed with integrated thermal breaks, reducing the direct contact between the cladding and the steel frame.
- Structural Thermal Breaks: For larger structural connections, specialized structural thermal breaks are available. These are designed to carry loads while also providing a thermal barrier.
Advantages of Building With Steel
Structural Superiority of Steel:
From the very beginning, I was drawn to steel frame homes for their exceptional strength. The idea of a structure that could withstand the test of time and the challenges of Mother Nature was incredibly appealing to me. I live in an area prone to seismic activity, and the thought of having a home with the strength to endure earthquakes and other natural disasters gave me peace of mind like no other material could.
The concept of durability was equally significant. I wanted a home that would require minimal maintenance over the years, allowing me to focus on creating lasting memories rather than dealing with constant repairs. Steel’s resistance to decay, pests, and the wear and tear associated with traditional building materials made it an obvious choice for someone looking for a hassle-free homeownership experience.
Environmental Sustainability:
Being environmentally conscious, I couldn’t ignore the sustainability factor that steel offered. Steel is highly recyclable, and I knew that when my home reaches the end of its life, the steel used in its construction could be recycled and repurposed. This aligns perfectly with my commitment to reducing waste and lowering my carbon footprint.
Cost Efficiency:
While the initial cost of a steel frame home can be higher than traditional construction, the long-term savings were a compelling factor in my decision. The durability of steel translates into fewer repair and replacement expenses, reducing the total cost of homeownership over time. Additionally, insurance savings due to steel’s resistance to natural disasters can be substantial.
Design Flexibility:
One of the most exciting aspects of choosing steel was the design flexibility it offered. I had a vision for my dream home, and steel allowed me to turn that vision into reality. The strength of steel frames meant I could have open and spacious living areas with large windows, creating a seamless connection with the outdoors. The architectural possibilities with steel are virtually limitless, and my home is a testament to that.