I've used both in my home, its unusual being a "sectional building" where even the outside walls are 3x2 stud walls. So I'm limited with thickness - so Airtec seemed a good supplementary option to boost the effective level of insulation. The theory is that the 6mm ish thick foil is equivalent to 55mm of kingspan. I've also used the same double method on the flat roof ceiling, although there I could only use 80mm kingspan and airtec again on the inside to allow a ventilation breathing gap above between the insulation and the flat roof immediately above it on the "cold side".
On the walls I used 60mm kingspan between the stud posts, and Airtec double stapled easily over the inside layer across the surface of the posts. Dead easy to fit with a stapler. You do need the foil tape and a couple of inches overlap, but you can also overlap where it meets the floor / ceiling.
I then attached battening horizontally across for plasterboard - which gives room for breathing gaps. You then need to go round filling gaps and holes around window frames etc. Of course going to such excessive lengths to stop cold draughts and air getting in means in the long term you have to add vents - but at least you're in control of it.
Eventually I will put a layer over the old floorboards before I put a new floor down - which should improve it to the same value all around. Its worse in my home because like a US home, I have a void 18" crawlspace below my bungalow that the wind howls into and up through the old floorboards!
Airtec works for me, if you live in a timber building with limited thickness on the walls its a very good option. I think anywhere you're limited with thickness its a definate problem solver - but you have to seal every join in every sheet!
In terms of living with it, as I've been living in it for a few months now through the early part of the winter, it holds heat brilliantly as it "reflects" the heat built up from humans or even electronic gadgets in the house.
As its hard to judge with seasonal variations over time - I hired a thermal camera and did a test, cranking up the heaters to a 26 degree test inside the home (at the ceiling level) then on a cold 6 degree night, I went up on the roof and measured the temperature of the flat roof surface, it was only 2 degrees above the air temperature - which means in theory I was only losing a marginal amount of heat - so it seems to work really well.
What I've noticed is you have to consider stabilising the air temperature in the house if you super insulate all round - any air leaks, windows etc cause hot air to cool and drop. As this stuff "reflects heat" it doesn't store heat, so the air in the room and your furniture/flooring is what ends up retaining heat.
The weak point now in my case is that I don't have the floor done yet, so the walls and ceiling hold the heat brilliantly, but overnight on a cold night, the floor being 2 degrees lower temperature starts to gradually lower the air temperature from the bottom of the rooms going upwards. after you go to bed and everything including the heating is switched off. So about 5 hours later, unless you have a really hot sunny morning sun through the east windows - the whole house drops to the temperature of the floor.
I think its great stuff, I got mine delivered by
Screwfix - very easy to work with. Most importantly - this stuff does work, the proof in the pudding is this - I have no heating yet apart from a couple of panel heaters - and when its 7 degrees outside, I'm at 21 degrees all evening.
Considering when I moved in there was no insulation and waking up on a summer morning after a clear sky night was unbearable - its a vast improvement - so I can recommend using it.
I think Rab C Nesbitt wore one
