Alternative to celotex and equivalents

[Nathan Williams]

Is there an alternative to celotex/kingspan and other rigid type PIR insulation which has a comparable thermal conductivity performance (around 0.025-0.027W/mK). Wood fibres seem to be higher than simple rockwool (circa. 0.047W/mK), and sheeps wool similar to rockwool (circa. 0.040W/mK).

[J Ingram]

I guess the simple answer is no
Some denser mineral walls are around 0.032W/mK
Slab 32 cavity batts by Knauf being on example
Aerogel has a lower U than the PUR,PIR, phenolic @ 0.012W/mk and can be laminated to other material such as plasterboard.

Worth doing some reading on the potential benefits of natural insulation, vapour permeability
and the effect this may play on insulation performance and U values. Still trying to figure that one out myself !

[Mark Siddall]

Springvale do an EPS Neopor based product - they call it platinum. Conductivity 0.03 W/mK

[Nathan Williams]

Thank you for your comments. The Dritherm 32 is being used on a project of ours at the moment as it meant a full fill cavity was possible. The reason I ask was in alot of situations I struggle to get the architect to consider larger cavities than 100mm, therefore achieving a decent u-value is difficult and relies either on the full fill approach (Dritherm) or partial fill with Celotex.

[Nick Grant]

Nathan

I assume you have seen Mark Siddall's article on thermal bypass?

Nick

[Mark Siddall]

Nathan,
Foam in cavity walls is a no-no from my perspective. External insulation only (and beneath floor slabs.)

Mark

[Nathan Williams]

Yes I did read Marks artical on the cavity issues. Very interesting - hence full fill cavity I assume are better.

Mark - why no to foam in cavities?

I think the phrase "horse for courses" comes to mind. External insulation is all well and good, however is not practical for all situations.

[Mark Siddall]

QA problems really. Mortar snots etc. causing air gaps behind insulation and cracks between the joints - thus bypass. Builders can not get away with such things with ETHICS as the defects would be apparent in the level of the surface.

Mark

[Matthew Richards]

Hi

I am looking to get my teeth into organisng an event that will study and hopefully make soem scientifically informed advise on the issues of thermal upgrading/retrofitting insulation to existing properties (including the particuarly difficult case of doing this to a solid wall historic structure. This will obviusly need some detailed building physics input.

I would appreciate some advise on best approach:

My thoughts are to look at the various options on the market today i.e external versus internal insulation, thermal break problems at say floor and roof junctions, vapour and condensation risk, fabric decay, plaster type, paint type, costs and practicality.

Do you think I would be best to involve a university with building materials research capability.

If this info is already available I would be grateful to know. however, from the questions I have asked so far this appears that there is not clear guidance (just worrying rumours!).

Thoughts appreciated

regards

Darren

[Nick Grant]

Darren

In terms of universities UCL come to mind. Neil May has contacts.

Clearly, where practical, external insulation sorts a lot of these issues. I'm hoping Alan Clarke will give a talk at this year's conference describing the journey with his own house. Years of incremental improvements followed by biting the bullet. Not always possible though.

Nick

[Geoff Stow]

Going back to the original question have you seen Edenbloc by Second Nature
www.edenbloc.co.uk

Geoff

[Nathan Williams]

Geoff

Thanks for that link - will look in more detail.