Internal wall insulation

[JT101]

Hi fellow eco warriors

I want to insulate the two external walls of the my tiny 2m x 2m box bedroom on the inside.

I've thought long and hard about this, and done plenty of research so I think I'm on the right track. Just wanted some feedback and other ideas.

Insulation requiring stud and framework wouldn't be ideal as I really can't afford to lose much space, so I think rigid board is the way to go. I ideally would like something with a very low k-value, non toxic in production, usage and end of life; and ideally low embodied energy (although that is not so paramount since better insulation properties will more than offset this in energy savings)

Came across Fermacell 0.032 W/mK (gypsum-fibreboard) and , Homaherm 0.040 W/mK (Cellulose slab). I would consider Kingspan or Celotex due to their incredible efficiency but I am concerned about their end of life waste.

The thickness would be ideally the lower end of 20-50mm range.

Cheers big ears

[grahamhobbs]

The most practicable is probably Thermalboard Plus, this is like Kingspan insulation bonded to ordinary plasterboard and the board (2.4x1.2m) is stuck to the wall with a plaster adhesive. It comes in various thicknesses in range you want. You can then skim or dryline the plasterboard as normal. They also do one with polystyrene backed plasterboard but this less efficient and can soak up moisture if the walls get at all damp.

[JT101]

Did you mean this: http://www.british-gypsum.com/products/ ... super.aspx

I can't find Thermalboard Plus

If it is the gypsum one, I took the R values supplied, and did the reiprical for U value, and they come out at 30mm = 1.03, 40mm = 0.67, 50mm = 0.5 W/m.K which isn't fantastic

Thanks

[boboff]

I am no expert, but I believe you can get this "foil" stuff which is thin and very good value thermally, then just use normal plasterboard, drylined?
It's not cheap mind.

[grahamhobbs]

JT101, sorry official name is Thermaline Plus, this I think is the easiest and most practicable. Bobof suggestion is good, the foil can be got from Wickes these days, but you need to fix 25mm thick timber battens to the wall, then the foil, then more battens and then the plasterboard. It will give a better U value but with more labour.

[JT101]

Can you be more specific about the "foil". i.e. a product name

Thanks

[boboff]

I could pop round and give a quote whilst I am about it?

No sorry, as Graham gives the name and the outlet, I think thats all I can give!.

Best of luck.

[grahamhobbs]

There are numerous manufacturers of what are generally referred to as multi-foil insulations, one of the first was Tri-iso super but there was a lot of controversy about whether it met the Building Regulations required U value and whether it's Agreement Certificate used the proper test. Some local Authority Building Control depts would not permit its use. Nowadays there are many other competitors. I think YBS is one that is fully certified. but you can also check out the ones from Wickes, B&Q, etc

[plumbers]

how about external insulation ? it saves space

[JT101]

Looking back on my original question I realise what a newbie I was and how much I've learned since then.

In answer to plumbers question, ideally I'd have both. But being an end of terrace house, taking space from the alleyway is tricky. Plus I can't afford it at the moment.

I ended up using phenolic foam. Bascially identical to Celotex. I used Xtratherm

I clearly didn't understand what Fermacell was. I even considered

Whilst Aerogel is amazing stuff, I think you can't beat phenolic foam for cost vs efficiency. Kingspan is only marginally better for a disproportionate price increase. I'm sure well see the cost of Aerogel come down and other materials available in the future, but this is where we're at now.

My room is still cold, but nowhere near as bad as it was. 25mm of insulation improves it somewhat, but you'd need a lot more to warm a solid brick wall. Ideally inside and out insulation.

Another area to watch for is the windows. I could see my curtains swaying with the draft!! I weatherproofed it to buggary. But the cold double glazed aluminium frames wick the heat away. So again, this ideally would be replaced.

Anyway, I was doing this to originally get rid of mold forming on the cold walls. This is not happening but then again it isn't that cold yet. Watch this space.............