The moment has come for us to put up the internal walls of our tiny house on wheels. It has taken us quite a while to get to this stage but the time has finally come!
First step: Insulating our walls
But before we can actually install our wall boards we have to insulate the walls. We went to our local warehouse and were looking for insulation with a high R-value. The R-value measures the resistance to heat flow through a given thickness of the material. The higher the R-value the greater the resistance.
In addition to the R-value, we were also looking for an insulation material that had the right thickness of our walls. Since our steel frame is quite thin our insulation couldn’t be thicker than 75mm. Unfortunately, with insulation that thin, the R-value is also not very high. But given our sunny and warm location (and the fact that there was nothing else available) we settled for insulation with a low R-value. So far it seems to be fine.
“Installing” the insulation is very easy. Simply fill all the gaps in your frame with it. I must say that, although this was super easy, it was my least favourite task so far. The insulation material is itchy on the skin with lots of particles flowing around.

Step two: Installing the wall panels
Once the insulation is in place it’s time to install the wall panels. We bought 6mm thin structural plywood sheets.
When installing your wall panels we found that the best method is to screw them on mid joist rather than the full panel. If you just screw them on panel by panel the plywood boards might bow because they have nothing to sit on. That happened to us along the ceiling. So we changed our method along the walls. You might end up with a lot more scrap that way but the end result is much nicer.
Also, before we even installed our plywood sheets we painted them with a white primer coat. We’re hoping that the primer helps to water and mould proof the panels.

Step three: Filling the gaps
Once all the plywood sheets are installed it’s time to fill the gaps between the sheets to give them a smooth finished look.
Normally, we would use something like Gyprock for the job but since our house is mobile we thought that the gaps might crack once we move it. So we tried a different method.
Instead of Gyprock, we used tape to close the gaps between the sheets and then filled everything with gap-fill. We used gap-fill because it’s more elastic than Gyprock. It might still crack when we move the house but, oh well…
Step four: Painting the walls
Once all the gaps in our internal walls were filled so they looked smooth and nice, we gave them their final coats of paint. To achieve a better result we painted them twice. Now they look all white and shiny.

The end result
Woo, our tiny house actually has walls!! That’s pretty awesome.
We’re still amazed by how different our tiny house looks now. The internal walls really have transformed it and the white paint makes it look big. Who would have thought that a tiny space can look so inviting and spacious?
Hi there,
ive just started my own build and would love to know how your 6mm plywood has been?
any cracks? ive been leaning towards a 6mm v grove board any thoughts?
Hi Dylan, thanks for your comment. So far we didn’t have any issues with our 6mm ply but we’re also not moving our tiny. God luck with your build! 🙂
Hello, just wondering what you meant by tape up the gap fill. Did you tape the joins and then put gap fill over them. I am looking at using ply as well. Also what grade and type of ply did you use?
Yes, we taped the joints and then put gap fill over it. We used 7mm structural plywood.
Although I have already watched your episode on LBIATH multiple times, it’s really awesome to see it all come together. These blogs posts are great. It’s been so overwhelming the whole process. I am hoping to be able to at least get our house locked up before October but it looks like we won’t be able to but we’ll be giving it a good try.
What did you guys end up using for insulation? Is that earthwool? I’ve been trying to source non-toxic, low VOC materials. It seems like there aren’t many builders like Ben Garrat here, or is it just my seraching skills haha