Hello I'd like to build a loft bunk (to house a king single) with a queen bed under (see picture below) - can you help with materials and methodology?
Hello @halid21
Welcome to the Bunnings Workshop community. It's wonderful to have you join us, and thanks for sharing your question about building a loft bunk.
If you are building a king single loft bed that may regularly have two adults and a child climbing into it, my recommendation would be to approach it as a small structural platform rather than a standard bunk bed. While a capable DIYer can certainly build a loft bed, once it is anchored into the walls and intended to support adult loads, the design, fixings, and bracing become much more important. The timber itself is often not the issue; ensuring the structure is securely fixed into the wall studs and that the loads are transferred safely into the house framing is what really matters.
A wall-supported loft can be incredibly strong and stable when built correctly, but because it relies on the home's structure, I would strongly recommend engaging the services of a carpenter to help with reviewing the design and assist with the structural components. They can confirm the wall framing is suitable, specify the correct fixings, and make sure the loft is properly braced to handle the movement and forces created by adults climbing, sitting, and sleeping on it. The cost of a professional review is usually small compared to the peace of mind that comes from knowing the loft is safe, solid, and built to last.
Child safety should also be a key consideration from the beginning. The loft should have sturdy guard rails on all open sides, with the top of the rail extending well above the mattress height so a child cannot roll over it during sleep. Openings in the guard rails should be small enough to prevent a child becoming trapped, and the access point should be designed so there is no risk of falling while getting in or out of bed. It is also important to avoid creating gaps where a child's head, neck, or limbs could become caught. Using the Australian bunk bed safety standard as a guide is a sensible approach, even for a custom-built loft.
I would also give careful thought to the access. If adults will be using the loft regularly, a proper staircase is a much better option than a traditional ladder. It is safer, more comfortable to use, and places less stress on the structure. If space is limited, a ship's ladder with angled treads can be a good compromise, but a vertical ladder would be my last choice for everyday use. Many loft designs also incorporate storage into the stairs, which can be a great way to maximise the available space while improving safety.
Overall, I think it is a fantastic project and absolutely achievable, but with adults and children using it regularly, a friendly chat with a carpenter before you start will be one of the best investments you can make. With good design, quality materials, appropriate child safety features, safe access, and the right structural advice, you'll end up with a strong, secure, and impressive loft bed that the whole family can enjoy with confidence.
I also recommend having a look at this discussion - Kids bedroom upgrade with bunk bed BY @Tara86.
I also suggest having a look at these double bunk beds if you are looking for alternatives.
Let me call on our experienced members @Tara86, @RobP, @Dave-1, @Nailbag and @DIY4Knuckleheds for their recommendations.
If you have any other questions we can help with, please let us know.
Eric
Good Evening @halid21
The first place I would start with is actually sketching your idea out, starting with the dimensions of your room (width, windows and height of the room)
Height of the bed bases plus mattress thickness to be considered.
Existing power points, light switches.
As you sketch up what you like/want you will see how pieces of timber will need to join. Fixing them to the studs in the wall as @EricL has mentioned would give it rigidity and as a peace of mind with the potential weight of the structure overall plus people I would also recommend to get a carpenter to have a look over your sketch.
Dave
