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The materials you choose to use for your tiny home are very important. But the options are truly endless for the trailer, the structure and the internal fitout. Like with any housing project, you have to lay the foundation first. For a tiny house project, the foundation will most likely be a trailer, depending if you’ll need towing or not.
If you’re planning on towing it, you will need to be conscious of the weight of the materials you use to avoid exceeding the trailer weight limit. From there, it’s all about the structural integrity of the house frame and then, the internal fitout. It might sound obvious, but your choice of foundation will influence whether the rest of your build succeeds or fails.
I often get asked for my thoughts on buying a second hand trailer. As much as I like reusing things, I always recommend buying a new trailer that is engineer designed and one that is specifically designed for your tiny home so you can get peace of mind from the beginning. I start by asking people the following questions so they can understand my reasoning for this position.
- Do you know what the trailer was originally engineered for and how old it is?
- What is the history of its use? Has it been involved in an accident? How has it been stored and how many kilometers has it travelled?
- Was it engineer designed or have you had an engineer check it’s structural integrity for weld points, steel gauge and presence of steel stress fractures?
- Has it been designed to support the weight you want to submit it to?
Another thing to consider is whether or not the trailer will need modifications to meet your requirements. If you cannot answer these questions and feel comfortable about the answers then I recommend you buy a new trailer. I know this might not be what people want to hear but consider the alternative – a structural failure that potentially causes an accident on the road when being towed.
The tiny home will also need to be built with materials that will withstand the climatic elements of where you choose to locate it. It needs to be weather tight and structurally sound for when it’s in place and when it’s being moved.
Next let’s talk about the building envelope, ie. the structure. What are your options?
You might be thinking of repurposing materials that you have salvaged, or made, or perhaps you’re keen to use new materials. No matter what the material choice – apart from structural strength, you’ll need to consider their weight. Every kilo of materials will make a difference and it will translate directly to the capacity of the trailer to support the final weight. My friend Fred of Fred’s Tiny House Trailers said to me it’s all about millimetres and kilograms when designing a tiny and I couldn’t agree more.
I suggest creating a spreadsheet and recording the weight of the sample materials you intend on using for the structure and then calculate the projected quantity. Remember the structural materials cannot be compromised, so you may need to pear down on the weight of the internal materials. Remember that the joining members such as screws, bolts and nails need to be added into the weight equation.
So what structural material do I use and why?
I choose to use structurally insulated panels for my tiny houses where the external and internal skin of the panel is Colorbond and insulated with polystyrene. My entire weight for my insulated walls and roof for my 6m tiny house is 700kg and my 7.2m system is 800kg.
When compared to timber and steel, that’s really low. That’s because my structural system doesn’t require plasterboard, external cladding or framing elements. Another reason why I chose this building system is that it’s so easy to construct with, has no ongoing maintenance and is very quick to build.
Other construction options are steel or timber wall frames and metal roofing systems. Again, it is important to buy new at this stage as unfortunately you wouldn’t be able to determine structural integrity of used materials.
You might love the idea of natural timbers inside the home, which can look great for cabinetry, benchtops and doors. Or if you want to reduce the weight, then consider a stainless steel benchtop, which can provide an industrial look. For cabinetry doors, consider using a Colorbond mini orb, or rattan in a frame, or no doors at all. The use of fabrics as the front of cupboards can also be a great way to keep the weight down.
In the bathroom it’s important to use a waterproof material for the floors and shower walls. Try to avoid tiles which are not only heavy but might not withstand movement. Instead you could consider vinyl or linoleum floor covering.
Fibreglass shower bases or cubicles are durable and lightweight, but you might want to install a bath. No matter what you choose, you will need to think about how you are going to avoid water splashing about, and one of the most common solutions is the shower curtain. But if space permits, then a shower screen is an option.
Let’s talk about flooring.
Lots of people use timber floorboards, but there are other options, such as plywood, marine ply flooring, cork tiles on a timber base, linoleum or vinyl. When choosing your flooring, also consider whether the material will require any ongoing maintenance, such as sealing or staining.
Lastly, your furniture and storage areas. Perhaps you might have special pieces of furniture that you want to bring into the tiny house, but it’s essential to consider how functional they really are. And remember, not everything has to have multiple uses, but certainly good functionality is key in tiny homes.
Think about where you see yourself eating and how large of a surface you’ll need. Consider a fold down or pull out table, or a larger portable table for entertaining. Do you want chairs or stools? Make sure they’re stackable or can be pushed away.
If you have stairs and need storage solutions there are so many options to make the stairs contain a storage area, either as individual storage compartments or for larger items such as the washing machine or clothes hanging.
The overall weight of your tiny home is very important.
Finally, let’s talk about the overall weight of your tiny house. It really boils down to whether the tiny house will be towed and if so, how regularly. Whilst you will need to refer to the road laws in your state, here are the common limitations: no higher than 4.3m from the road, no wider than 2.5m, and no heavier than 4.5m tonne. The length of the trailer from point of articulation cannot exceed 12.3m. Just remember, there are only a couple of cars that could pull 4.5 tonne. If you want to keep it under 4.5 tonne, you will need to consider the tiny house length and this will really depend on your selection of building materials.
Another method to consider is using a towing company to tow your tiny house to site. There are a number of towing companies that will tow tiny houses and they provide insurance cover when towing and usually charge on a kilometer basis. If you are going to organise private towing by yourself or a friend, you will need to make sure that the towing vehicle is legally allowed to tow the total weight of the trailer and tiny house and that it has automatic brakes rated up to 4.5 tonne. It’s advisable to go over a local weighbridge before moving it far to ensure that tiny house is under the allowed gross weight for the trailer. If your weight is over, you might need to consider taking out furniture to reduce the load and move it separately. Remember, it is not the individual weight of items that you should consider, it is the collective weight.
Today we have covered off the importance of buying a trailer which is suitable for your needs and is the foundation of your home, the structural building materials and the internal fitout. We have also explored material choice and how they influence weight. Next time I will be talking with you about building your tiny and regulatory compliance. Onwards & upwards!