Has anyone come across or know anyone who has used the Mantle Panel System?

http://www.mantlepanel.com/environment.html

Is it a viable alternative to Timber frame? They have BRE accreditation and LABC approval.

Peeps thoughts would be much appreciated

Thanks

I am concerned about the idea of combining structure and insulation, my feeling is that it is not at all a bright idea in principle.

Tony
Do you have any reasons for your concerns? or is it just lack of history for the technique?

Seems to remember that there were similar concerns when cars (and planes) went to monocoque construction.

Tony
I see what you mean. Worth splitting it up into design and materials though, they are quite separate.
One thing that does intrigue me is why we over engineer houses so much in the UK. Do you think it is to do with quality control, which is sadly lacking in the building industry?

Only thing that would concern me is the choice of PU. Having worked with that material for over 30 years, I know that properties vary and it can be very temperature and humidity related during production. When making small components, this may not be a problem as faulty ones can be easily discarded, but with a large SIPs panel the rejection costs can start to get to high.
There is also a long term stability problem, expanded PU tends to keep shrinking for years, quite often this is overcome by pumping a bit more mix into the tool. Initially this seems to work but over time the shrinkage can become worse than slightly underfilling.

Posted By: tonythermal bridging at the joins and corners

This system seems to address that quite well. Better than SIPs any way.

<blockquote><cite>Posted By: SteamyTea</cite>Only thing that would concern me is the choice of PU. Having worked with that material for over 30 years, I know that properties vary and it can be very temperature and humidity related during production. When making small components, this may not be a problem as faulty ones can be easily discarded, but with a large SIPs panel the rejection costs can start to get to high.
There is also a long term stability problem, expanded PU tends to keep shrinking for years, quite often this is overcome by pumping a bit more mix into the tool. Initially this seems to work but over time the shrinkage can become worse than slightly underfilling.</blockquote>

The degradation of PU is something worth looking at more closely. There was a trend to use PU foams for core material in composite light aircraft years ago, until there was a spate of core failures, In the worst case I personally saw a vertical sandwich panel lost most of the core when it turned to dust - we cut a hole in the base of the panel and the core material ran out like sand. The problem was two fold; poor control of the mix of chemicals when the foam sheet was manufactured and temperature cycling over several years.

I've also experienced the shrinkage problem. I used two pack PU foam (probably very similar to the stuff used to make SIPs cores) to stiffen the solar panel canopy on my boat (it has thin ply skins, curved over laminated timber frames). This has shrunk enough over the past year or so as to give the panel underneath a "hungry horse" look.

I'd like to hope that construction grade PU foam cores are very long lived and don't suffer from these problems, but I wonder how anyone would know in practice when they form the structural core of a house? Testing will have been done under controlled conditions where failure could be spotted, but I doubt you'd get any clues about core failure in SIPs panel.

There's a thread here somewhere about supposed PUR degredation. Cwatters did a very good job of explaining that any degredation is taken into account in the manufacturers stated lambda values. I'll see if I can find it

Ah, my mistake. Good topic for discussion. Brings to mind a whole host of applications where materials/renders are bonded to insulation such as EWI.

I notice on their website that any cladding or render can be adhered.

OK, but, getting back to Mantle, the YouTube video says it is constructed by laminating the layers together. It also looks more like an EPS material than PIR/PUR (larger beads).

Strange you should talk about PU having "turned to dust" because I recently sent a tube of low-expansion foam back to Dow Corning because it had literally turned to dust when it had cured. Never seen the like before.

A particular mystery because it came in the (standard) pack of five with an applicator gun. That tube was the fourth of the pack, all the others having performed normally, as did the fifth tube that was used after it. I did wonder if the few months since last using the pack had been enough to allow deterioration and on that basis fully expected the fifth tube to give the same problem.

I'd used it to fill the small gaps around the architrave on one of the sash windows I'd recently double-glazed. Left it for an hour whilst I had lunch. It all looked normal, but as I went around with the old pull-saw I use to trim the stuff back it literally crumbled into dust. Thinking it must have been "something" on the job (although there was nothing different to any of the previous three windows I'd done) I squirted a line onto a board in the workshop and left it to go off. Normally you can peel off such a line in one go, but this just crumbled to dust in my fingers.

I emailed Dow Corning and they asked to see the tube, which I duly sent off to them. Subsequent testing by them had the stuff behaving perfectly normally!

Tested the gun used on the fifth tube and it worked perfectly, so it wasn't the gun.



Bit wary of using the stuff in areas I can't see into now.

I'd be interested why they recommend dry lining internally?

Yes, they mention services on the video, But cables and pipes could just as easilly be accomodated within floor voids and boxed in corners inside the thermal envelope.

Just had an email from them saying it is EPS and quotes a U value of around 0.1 (depending on design). Quite interesting especially as you can render direct on to it and I suspect the impact resistance is pretty good.

Posted By: djhWhere do you see that?

http://www.mantlepanel.com/safety.html seems to imply there is no such need.

4'.50 into their you tube video. Prior to that they say all mantle panel walls have a 60' fire rating but then they add this stuff to the internal walls. Maybe if it's multi-occupancy - it wasn't clear to me why.