I thought I’d write about my recent project of building a camper bed for my Honda Civic, mainly because I found it was hard to find information online about car boot sizes or blog posts written by people who have done similar projects.
Before I started I was uncertain about whether the Honda Civic would have enough space in the back for me to lie down straight. I actually bought my car based on this criteria – I had recently sold a campervan and was having withdrawals. So during a viewing, I asked to fold the seats flat and actually tried lying in the back as a proof of concept. If you are considering the project for yourself, here is a diagram of the area formed by the boot and back of the rear seats when they are folded flat and the front seats are pushed forward. The shape of the sleeping area is awkward, as the centre console sticks up about 10cm higher than the platform, and quite far behind the front seats. So any mattress will have to mould around this bump.
Even once I’d bought the car, I wasn’t sure how best to go about turning the back of the car into a comfortable sleeping platform. I know that I don’t sleep comfortably on narrow or uneven beds. So I wanted a flat sleeping surface that covers the entire rear of the car, to avoid the feeling of having to lie completely straight to avoid falling off a raised platform. The mattress would also have to be hard enough that I don’t sink too much when I sit up or shift my body.
I built 2 platforms to fill in the gaps between the rear and front seats (£10 scrap wood). On top, I build a multi-layered bed until I was like princess and the pea:
Parcel shelf and cushions in boot, 9mm ply on back seats (1.2x0.6m, £16).
2 self-inflating camping mats (£40 total)
5cm thick foam mattress topper, cut to size (£10 second hand)
I had ruled foam out because I thought there was no way I could get away with a thin piece of foam, and didn’t want the hassle of storing a thick piece. But combined with the inflatable mattresses and an rigid, flat platform of plywood, it was just right.
I could sleep completely straight, opting to put my head at the boot end as there is more width to move around. The space would definitely sleep two people of my height (5’10”) as long as you don’t mind being cosy. I am a light person so someone heavier than me might find their hips press against the wood underneath, but that could be prevented with a thicker inflatable or foam mattress.
4 stages of making the bed
I bought a roll of foil insulation (£15) and cut out window blinds that were ever-so-slightly bigger than the windows. That way, they held themselves in place once I’d stuffed them into the nooks and crannies surrounding each window. Total blackout, perfect for a lie-in if you don’t get too damp.
I finished it off with a custom sewn mattress cover (£5 for fabric), some fairy lights, and my actual bedding – it didn’t feel like camping at all! The overall cost was under £100 which was great since I want to adapt or recreate the bed for any car that I own in the future.
Double inflatable mattress
My initial idea was to use a thin almost-double inflatable mattress, which I ruled this out because of the awkward ‘bump’ (the centre console) in the middle of the sleeping area. This would have raised the mattress by 10cm above the sleeping platform and not left enough room for sleeping let alone sitting.
Custom PVC mattress
A homemade PVC mattress would solve the awkward shape problem because I could make it fit around the bump. And it would be easier to store than foam, and comfortable enough as long as it kept pressure (see here for an idea of how to maintain mattress pressure over time).
There is plenty of information online, since the DIY pack rafting community make TPU plastic inflatable chambers. The process involves welding together separate sections of TPU-coated fabric in a waterproof way (instructions here). You need some equipment and patience. I suspect one of the most important tips from the article is that you need to overlap joints (one layer on another) so that they only experience shear force rather than peeling force.
I had a cheap PVC mattress to hand, and so decided to test the concept with this. PVC does not respond to heat-sealing in such a neat way. Instead people recommend are to use the same technique as you would use when repairing an air mattress: use some PVC glue and overlapping PVC sections to produce a strong, airtight joint that will not peel apart when the mattress is inflated.
I cut the mattress to shape, leaving extra material to join together and make new ‘sides’ of the mattress. I then used Bostik soft plastics clear glue (£20) to start gluing the edges together. It was time consuming and very difficult to get the fabric to form an airtight seal, and in the end I went with the other lazier but good-enough option.
Other car options
I recently sold my large campervan and was looking for a car to replace it as a day to day vehicle. I wanted to see if I could keep the main benefit of a campervan – a bed more comfortable than camping but cheaper than a hotel.
I initially considered Berlingo / Partner / Doblo as I know plenty of people who sleep in the back of these very comfortably, and there is a bigger community out there. But in the UK it seems like most of the cheaper ones have been converted to mobility vehicles.
I didn’t want a large family car / SUV so I tried to find the smallest car that would allow me and one other person to comfortably sleep in the back. I didn’t look at that many models, but I’m pretty sure the Honda Civic Mk9 (2012-2015) and Mazda 3 are similar in size and both have rear seats that fold flat.