How to build a double loft bed?

maddi1

Hi, I am wanting to build a double loft bed to suit 2 adults but I want the base bigger than the mattress so I can put storage above too. I was thinking along the dimensions of 250cm long and 140-150cm wide and the base of the bed to be about 150-165cm high. I have no idea on how to get started or approximate costs if anyone can help guide me it would be greatly appreciated. I’ll attach a picture of the gram I want to build just different measurements. (Also needs to be rental friendly).

JacobZ

Hi @maddi1,

Welcome to the Bunnings Workshop community, it is fantastic to have you with us.

Being a rental, you can't really anchor things to the ground and walls, which makes building a large structure like this a bit complicated.

It sounds like a fun project, but I will warn you that to build an elevated structure like this, you need to use structural-grade timber, and the calibre of materials required is probably a fair bit larger and heavier than you are expecting.

Without being able to build and test the structure, I need to rely on verifiable information, and the closest thing that is readily available is the guidelines for building timber decks. 

Any structure like this needs to start with posts. I'd suggest something like a 100x100 timber post would be suitable.

You would then, essentially, be building an elevated deck, so we can use a Bearer Span Table to work out the calibre of timber needed to span longways between the posts, which at 2500mm long, would be fairly large. You would be looking at something along the lines of a 240 x 45mm. You would need one of these bearers to run between the posts on each side of the bed. They will attach to the posts with cup head bolts. 

Any timbers that span between these bearers would be treated like the joists on a deck, so we can use Joist Span Tables to select a timber capable of spanning that distance. In this instance, 90x45 timbers spaced at 450mm intervals along the length of the bed will suffice.

 

You would then need to laterally brace the posts, as any movement at the top of the structure will be amplified down the posts. This can be done by adding braces 450mm above the ground. 

To have at least one open side without the braces, you would need to add angled braces to help with that lateral bracing.

You could then add a ladder to one end and paint it how you like.

Unfortunately, at the size and height of your project, I couldn't see a way to build it with fewer materials and be comfortable that it could support your weight. 

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob