Insulation problem with tinfoil bubblewrap material

[Ian 56]

 

A friend who is selling his house has just had a diagnostique inspection of the property. The loft area has been insulated using the tinfoil, bubble wrap material which has made a great difference to the comfort of the house and which is claimed to be equivalent to 200 mm of fibreglass. However in the assessment of the Performances Energetiques he was told by the inspector that this form of insulation is not acceptable and counts for nothing. Can anybody confirm this as I am considering using this material?

ian

 

[mint]

This tinfoil stuff was installed by the previous owner and I personally don't think it's much good because last winter, I found the house horribly cold despite woodburners, paraffin heaters, electric radiators, etc.

We have had our roof completely stripped and rock wool/fibre glass stuff put in between the purlins.  It was early spring when we had this done so can't say yet about the thermal effects but traffic outside is now much quieter so the sound effects have been good. 

[Chancer]

I am in the process of insulating 100m2 of roofspace with extruded polystyrene between the chevrons and 17 layer mylar isolant mince, as the apartments will be rented I too will have to fork out for what now looks lto be a pointless energy survey, the inspector has confirmed what I thought would be the case.

I have never really understood why there have never been any accepted insulation figures for this type of material, whilst I am not convinced that mine is the equivalent of 240mm of laine de verre it is undoubtedly very good and arguably better than traditional insulation between the chevrons as it removes the thermal bridge.

Still if it is not on the no doubt recently hurriedly trained spotty youth "inspector"s checklist, then clearly my roof is uninsulated [8-)]

[Gluestick]

[quote]

Still if it is not on the no doubt recently hurriedly trained spotty youth "inspector"s checklist, then clearly my roof is uninsulated

[/quote]

No doubt he has his "Sustificate, Mate" though, JR.

I recently went through such a charade with an "Asbestos Inspection" on commercial property. The "Surveyor" who turned up was a Director of a company which was not even a member of the main trade association: but had, no doubt, attended one of the numerous few days courses similar to HIPS courses, which take a bozo and turn them into an "Expert", thanks to a thousand quid changing hands..............................

Perhaps someday someone clever could explain to me how a Chartered Surveyor cannot provide a HIP; but an ex-estate agent with attitude and a short course can.

 

[La Guerriere]

For some real tests on multi-layer foil insulation, read .....

www.foam-insulation.co.uk/building-regulations/BRE-multi-foil-insulation-measured-u-values.pdf

This makes mighty interesting reading

 

[Gluestick]

Surely, such tests wopuld only have any quantifiable scientific meaning when and where control facts were introduced, such as building a test structure and employing precisely identical insulation material support (wood battens e.g.) and thereafter empying most commonly used insulation methodologoes and materials and then tabulating U values one to another, as comparitive.

Unfortunately, for me, the final attribution, viz:

[quote]

The work described in this report was supported by the Office of the Deputy Prime Minister.

[/quote]

Provides cause for concern............

It was this very same organisation which was responsible for the wondrous HIP.

[Www]

[Albert the InfoGipsy]

The Building Research Establishment was not impressed

http://www.foam-insulation.co.uk/building-regulations/BRE-multi-foil-insulation-measured-u-values.pdf

If anyone has a few days to spare you might want to read this thread:

http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=125&page=1#Item_0

Which was a follow-up to at least one earlier one, totalling about 1,000 posts.

My feeling is that if you have a situation where there is no room to install conventional insulation then multi-foams are better than nothing.

 

[La Guerriere]

The BRE tests were the standard tests done of insulation and can be directly compared with other published U-values. Two loos Prescott did not have anything to do with it (praise be).

[tegwini]

We've just had our top floor re-done and used a 'sandwich' insulation  ( 13 layers) which was not cheap. 

I was assured  that this was the most modern and best way to de this, as we originally had an unbelievably high quote, euro 40K, to do this with the French builder using this stuff.  We have raised the ceiling heights and used the insulation close to the purlins & rafters, with placo to finish.  The French builder we sub-contracted (and saved lots) also liked the sandwich insulation.

I rather think the French are in advance of us in the UK in this field.

I am assuming it will improve the insulation.  Anyone else used it ?  

Many thanks

Tegwini

[Anton Redman]

It will improved the insul;ation and when properley installed can produce measurable results but here is the rub no UK importer or manufacturer has been able to produce an installed and tested. The UK Advertising Standards Authority will not I believe allow adverts which say 'Equivalent to 40 mm of glass fibre' or specefic U or R values which cannot be tested to be quoted. I believe the French situation is similar as Bricodepot no longer publish these figures in their catalogue.

[Scooby]

We've just had our house done.  In the main part of the house we have had 240mm of laine de verre put in when it was being reroofed.  The part of the house that didn't need reroofing we insulated (again with 240mm of laine de verre) from the inside using a screw on metal framework covered with placo.  We have noticed a massive difference in temperature and in the heating bills.  We paid 4k euro for the insulation for the main part of the house (plus 14k euro for the reroofing) and 2k euro for the section insulated from the inside.   Our house is 250 m2 on two floors.

The only downside in respect of the boarding out on the inside was that, because we have mansarded ceilings, it has meant the vertical sections of the walls finish at a much lower height - a bit of a pain for fitting in headboards and furniture.

[WJT]

[quote user="tegwini"]

We've just had our top floor re-done and used a 'sandwich' insulation  ( 13 layers) which was not cheap. 

I was assured  that this was the most modern and best way to de this, as we originally had an unbelievably high quote, euro 40K, to do this with the French builder using this stuff.  We have raised the ceiling heights and used the insulation close to the purlins & rafters, with placo to finish.  The French builder we sub-contracted (and saved lots) also liked the sandwich insulation.

I rather think the French are in advance of us in the UK in this field.

I am assuming it will improve the insulation.  Anyone else used it ?  

Many thanks

Tegwini

[/quote]

Tegwini, is that similar to the Triso Super 9 insulation?

[WJT]

OK, lost Tegwini but does anyone else know if this is the same as the Triso Super 9?

[shimble]

personally speaking.... i have used the multi layer tinfoil on both interior walls and roofing space.....in the roofing space i have found that it is effective however i have spent time making sure that all the edges are well sealed using the aluminium tape and that i have sufficient overhang in the areas that could be susceptible to draft. the foil has illiminated all the draft into the roof space and in winter did indeed keep the heat reflected into the room below this is without plasterboard and the foil was fitted from the inside. on the exterior walls where it has been used i noticed an immediate diffference after fitting changing from what was a cold damp wall surface to a warm dry surface. overall i am happy with the results and find that well installed this gives a good barrier between the outside elements and the inside. but.... i have then used laine de verre to give further insulation (although my previos comments are based on just foil insulation) r values and u values mean nothing to me but cold and damp do and the areas that havebeen insulated have drastically changed i dont think the foil is useless but i dont think either it should be considered as the sole form of insulation..... the installation is however important the better it is sealed the more effective it will be.....it is a bit more involved than a quick staple it on and a bit of tape and the air space betwwen wall and foil and foil and inner surfaces should be respected ........ also note that as this is a metal based insulation it can conduct electricity and it should be earthed to your consumer board i wonder how often this is ignored .......anyway im no expert just putting my deux centimes worth in and regardless of reports advices and opinions i shall continue to insulate my house in this method even if it takes time and care to do properly and maybe a bit expensive ....

[tegwini]

Hi   WJT

Tegwini, is that similar to the Triso Super 9 insulation?   WJT

Busy yesterday!  Had a freezer crisis!! 

But, not sure the name of the insulation, or what it's similar to !   It wasn't cheap- over  euro 130 per roll at Leroy-Merlin, and less at Bricodepot.  13 layers costs more than fewer layers. Some of the layers wool type stuff, the outsides foil, maybe foil inside. We just left the huge bags to M. L'artisan and the keys!

The original quote was with a large company specialising in wooden houses and the Chef recommended a multilayer insulation.

Regards

Tegwini

 

[WJT]

Thank you Tegwini. [:)] I wasn't sure if you were talking about the same thing. Sounds like they are all similar just different names.

[Chancer]

I recently finished the mammoth task of insulating my grenier and am working in their every day during the heatwave, today I decided to take some comparative temperature measurements.

My roof has clay tiles without ecran sous toiture, I cut 20mm extruded polystyrene "tiles" to be a push fit between the chevrons and fitted them overlapping to be the first line of  defence against rain and snow ingress followed by 17 layer isolant multi-couche from Leroy Merlin.

Before in summer the heat in the grenier was insupportable, and everyone now comments on how cool it feels, I have not yet put up any placo.

Today the tiles were at 59 degrees celcius and the insulation at 31 degrees, the temperature measured in the middle of the room was also 31 degrees, this is not the whole story as there is a lot of radiant heat being reflected by the foil, I have 6 large veluxes on the south elevation and the sun coming in from that side is bouncing off the insulation on the other and gave me severe sunburn before the weather even got hot, I am now wearing factor 20 to work indoors!

A comparitive measurement on the 1st floor showed the floor to be at 21 degrees but 31 where the sun was shining through the windows.

I reckon that when I have the placo up and if I use the blinds the loft will be very cool to work and live in, even at 31 degrees it is relatively cool compared to the outside temperature, I can certainly see why the cannabis growers use the stuff.

When I get too hot and bothered I go into the cellar which is at 15 degrees - bliss [B]

[Clair]

We have found the same pleasant improvement under our canal tiles.

We too have used "tin-foil" insulation to insulate the attic (40-odd m²), but added some left-over Rockwool mainly over the north face.

We have three large (1.3 m²) Velux windows on the south-facing side. We chose to go for the "Comfort" version, said to stop 77% of the heat in summer. Each window also has an outside blind.

The current outside air temperature is 29°C; inside it is 21°C downstairs and 23°C in the attic.