DIY Doctor UK DIY Forums

I have a new log cabin which I've decided to add insulation to.

The concrete base had a DPM added during construction. The tanalised battens are resting on the concrete directly. I want to add PIR board but understand that ideally I should have DPM under the PIR.

Can I lay a simple DPM over the battens, working it down into the gaps and then just lay the PIR onto that or is there a better way to approach this problem?

I did see suggestions that I could float the PIR on screws screwed into the battens, so that it doesn't contact the concrete base. Is that a suitable alternative solution, or would I still need a DPM?

Thanks in advance for any advice

Hi b4con,
Since you already have a DPM in the concrete base there would be no advantage in adding another one. Ideally you need the PIR boards to be level with the top of your floor joists, if the boards when fitted are below the top of the floor joists fit strips of timber fixed to the sides of the floor battens at the bottom, to correct this - tiling battens are ideal.
Regards S

That's great, thanks so much. The PIR is 40mm, the existing battens are 47mm sides so I'll look for some beading to bridge that gap.