Cost of Metac insualtion and airtight membrane

hexosan

Metac insulation 180mm (4.8 sqM per roll) @ €52.00

vario airtight membrane 40m x 1.5m @ €154

Pro Clima intello airtight membrabe 50m x 1.5m @ €215

Anyone get any better than these prices ??

rampantbunny

Not the same thickness's but might give you an idea...
Metac Isover 220mm @ €12.30/m2 inc. VAT (3.86m per roll)
Metac Isover 50mm @ €3.50/m2 inc. VAT (14.4m per roll)

Your quote for 180mm (4.8 sqM per roll) @ €52.00 is €10.80/m2 but don't know if your's is with/without VAT.

ProClima airtight membrane 1.5 x 50 (75m): €125 ex.VAT
ProClima airtight membrane 3 x 50 (150m): €251 ex.VAT

hexosan

Thanks for that, mine all include vat.

I see I'm getting rode on the price of the intello.

hexosan

Just an update

Knauf Metastud
€11.99 sqM for 220mm
€4.61 sqM for 50mm

Metac
I'm waiting further prices for Metac tomorrow which I'll add

hexosan

Has anyone used or heard of Isover's Airtightness membrane Vario extra safe.

My roof build up is
Slate
2x1.5" baton
Solitex
225mm rafter

Isover claim I can fulfil the rafters with 220mm Metac without leaving a ventilation gap (as roof isn't counter batoned) if I use their product Vario extra safe. Their technical dept claim this will allow the roof to sufficiently breath and won't cause issues with timber rot.

rampantbunny

hexosan wrote: »

Has anyone used or heard of Isover's Airtightness membrane Vario extra safe.

My roof build up is
Slate
2x1.5" baton
Solitex
225mm rafter

Isover claim I can fulfil the rafters with 220mm Metac without leaving a ventilation gap (as roof isn't counter batoned) if I use their product Vario extra safe. Their technical dept claim this will allow the roof to sufficiently breath and won't cause issues with timber rot.

My engineer told me he wouldn't accept a roof done as described regardless of membrane type. I wasn't planning on it anyway. Does yours have an opinion on it?

BryanF

hexosan wrote: »

Has anyone used or heard of Isover's Airtightness membrane Vario extra safe.

My roof build up is
Slate
2x1.5" baton
Solitex
225mm rafter

Isover claim I can fulfil the rafters with 220mm Metac without leaving a ventilation gap (as roof isn't counter batoned) if I use their product Vario extra safe. Their technical dept claim this will allow the roof to sufficiently breath and won't cause issues with timber rot.

I would expect double battens above in order to 'fully fill' between rafters

galwaytt

hexosan wrote: »

..Isover claim I can fulfil the rafters with 220mm Metac without leaving a ventilation gap (as roof isn't counter batoned) if I use their product Vario extra safe. Their technical dept claim this will allow the roof to sufficiently breath and won't cause issues with timber rot.

^^^^^, I wouldn't. Their 'technical department' won't be any use to in the event of a problem or claim, down the road.

And, if you think about it, if filling it allows air through, "to breath", well imho it's a heat path as well.

Vented space required.

hexosan

rampantbunny wrote: »

My engineer told me he wouldn't accept a roof done as described regardless of membrane type. I wasn't planning on it anyway. Does yours have an opinion on it?

As always waiting for a call back from at least four messages to the engineer

hexosan

BryanF wrote: »

I would expect double battens above in order to 'fully fill' between rafters

Due to an error on site roof wasn't counter batoned so that's not an option unfortunately

BryanF

Leave 50mm air gap below the felt.

galwaytt

hexosan wrote: »

Due to an error on site roof wasn't counter batoned so that's not an option unfortunately

Of course it is - remove, add, replace.

You can't ignore it if it's 'wrong'.

rampantbunny

galwaytt wrote: »

Of course it is - remove, add, replace.

You can't ignore it if it's 'wrong'.

The whole roof...slates off and all?

BryanF

rampantbunny wrote: »

The whole roof...slates off and all?

Have you a main contractor? Was it described in the contract documents? I'm not suggesting you remove the slates but be prepared to install venting into that roof - your architect should be advise you in this

hexosan

BryanF wrote: »

Have you a main contractor? Was it described in the contract documents? I'm not suggesting you relive the slates but be prepared to install venting into that roof - your architect should be advise you in this

Originally explained to 1st roof who pulled out two days before start of job was replaced by 2nd roofer the next day. It wasn't his fault as he wasn't aware it was been counter batoned. Roof was practically felted and batoned when it was noticed.
Roof has been vented at eaves and ridge as per Tegral's spec. Roof as since been slated so they won't be coming off.

Arch and engineer work together as a team and one is as bad as the other, and as stated in previous threads the professionals we employ arent always as professional as ye guys on boards.

hexosan

I've spoke with the engineer about using vario xtra safe and he's said he's encountered it once before and if their technical dept produce a cert stating it complys with part F ventilation he'll sign off on it.
Their tech dept claim they can provide this cert and I'm waiting for them to email same. They claim that it's covered to work even on non breathable felt so there's no issue with breakable felt (solitex)

hexosan

I've looked at knauf omnifit stud earthwool 220mm it has a thermal conductivity of .034w/Mk and a thermal resistance of 6.45w/mk

Isover Metac 220mm has a thermal conductivity of .034w/mk and a thermal resistance of 5.25w/mk

Both are priced roughly the same does the thermal resistance make much of a difference.

Calahonda52

hexosan wrote: »

I've spoke with the engineer about using vario xtra safe and he's said he's encountered it once before and if their technical dept produce a cert stating it complys with part F ventilation he'll sign off on it.
Their tech dept claim they can provide this cert and I'm waiting for them to email same. They claim that it's covered to work even on non breathable felt so there's no issue with breakable felt (solitex)

OP, how does all this fit in with the Tegral eaves and ridge venting system?
Whats the air path?
Doe it not require counter battening?

sydthebeat

1. ask them for a copy of the BBA or NSAI cert
2. check the BBA or NSAI cert for certification in a 'full fill' situation
3. ask to see a copy of the report on "dynamic condensation and moisture risk analysis" in accordance to I.S. EN 15026:2007 Hygrothermal performance of building components and building elements - Assessment of moisture transfer by numerical simulation.
4. ask them for verification that the install is in accordance with their manufactures specifications and certifrication requirements.

then and only then should you accept it as a valid construction method,

hexosan

sydthebeat wrote: »

1. ask them for a copy of the BBA or NSAI cert
2. check the BBA or NSAI cert for certification in a 'full fill' situation
3. ask to see a copy of the report on "dynamic condensation and moisture risk analysis" in accordance to I.S. EN 15026:2007 Hygrothermal performance of building components and building elements - Assessment of moisture transfer by numerical simulation.
4. ask them for verification that the install is in accordance with their manufactures specifications and certifrication requirements.

then and only then should you accept it as a valid construction method,

I'll copy and paste this into an email and see
What they get back with. Rep rang at 4.30pm looking for exact roof build up, type of slate etc. said he was on to the tech dept on the other line. Interested to hear what they come back with tomorrow

hexosan

Right below is what the tech Dept replied to the the rep which was forwarded to me:

Further to your enquiry, regarding the use of Full fill Metac between Rafters on a Pitched roof. It is our opinion that using
Vario Extra safe, on the inner face of the rafters with full fill Metac will allow the structure to suitably breath. This will allow
vapour release to the inside when required, due to intelligent technologies in the Vario Extra Safe. Please see attached our product
literature on Vario Extra Safe for any further information or contact me to discuss.

hexosan

sydthebeat wrote: »

1. ask them for a copy of the BBA or NSAI cert
2. check the BBA or NSAI cert for certification in a 'full fill' situation
3. ask to see a copy of the report on "dynamic condensation and moisture risk analysis" in accordance to I.S. EN 15026:2007 Hygrothermal performance of building components and building elements - Assessment of moisture transfer by numerical simulation.
4. ask them for verification that the install is in accordance with their manufactures specifications and certifrication requirements.

then and only then should you accept it as a valid construction method,

I contacted the rep and said the above reply (post #21) wasn't good enough and forwarded syd's four points and asked them to clarify all before i could move forward so it's gone back to the tech dept

hexosan

hexosan wrote: »

I've looked at knauf omnifit stud earthwool 220mm it has a thermal conductivity of .034w/Mk and a thermal resistance of 6.45w/mk

Isover Metac 220mm has a thermal conductivity of .034w/mk and a thermal resistance of 5.25w/mk

Both are priced roughly the same does the thermal resistance make much of a difference.

Any takers on this

Calahonda52

hexosan wrote: »

Any takers on this

http://en.wikipedia.org/wiki/Thermal_resistance

If I understand it correctly this issue is related to the idea described here
http://www.designingbuildings.co.uk/wiki/Decrement_delay

Do you have a density figure for both products?

The way it was explained to me some time ago was that say you have two materials with same U value in a south facing roof roof and that one of them is twice as dense as the other: e.g. wood fibre vs foam.
The heat from the sun will pass through the foam more quickly than the wood fibre and overheat the room. Its an issue in converted dormers.
Hope this is a, correct and b, helpful.:)

Calahonda52

hexosan wrote: »

I contacted the rep and said the above reply (post #21) wasn't good enough and forwarded syd's four points and asked them to clarify all before i could move forward so it's gone back to the tech dept

I don't believe they have the syd specified paperwork for this one yet, I may be wrong so lets see.
However suppose they don't and you decide to go with the "comparable" material from the same stable as the Solitex, then this brings you back to the ventilation issue they was part of the design when cross battens were specified.

Again, I may be wrong, but the tegral eaves and ridge ventilation system has an airflow in the space between the Solitex and the slating battens created by the counter battens.

Does the solitex require cross battening?

hexosan

And this is what the tech dept came back with:

""""Further to your recent enquiries regarding the use of full filling Isover Metac insulation, using Vario XtraSafe to the underside of rafters on a pitched
roof we can offer the following advice.

Within the Isover Vario range of products there are now two intelligent air-tightness membranes, Vario KM Duplex and Vario XtraSafe. Vario KM Duplex has been an Isover product used successfully on the continent for approximately 20 years and has been sold and used successfully in Ireland for 10 years. During this time it has been proven to be a performance related leader in the market. Demonstrating successful application of full fill mineral wool insulation solutions below breathable roofing systems.

Demonstration of the successful performance of the Isover Vario membranes in various situations and locations has been undertaken using a dynamic software assessment tool called WUFI. WUFI complies with all requirements of standard EN 15026:2007.

The new Vario XtraSafe membrane, which has the largest available sd range of any comparable membrane product on the market, is changing the rules with regards to traditional building physics practices. The implications of the XtraSafe material’s larger sd range can allow the use of mineral wool applications below certain non-breathable roofing situations. Isover have worked closely with the Fraunhofer Institute in Germany, where the dynamics of WUFI were originally established and proven by practical experiments, to establish the properties of the Vario products. Isover have carried out WUFI investigations/calculations which demonstrate our details and claims for a mineral wool “full fill” situation using Vario XtraSafe.

Please note that whilst WUFI calculations have demonstrated that Isover Vario XtraSafe may also be used in unvented flat roof situations, with torch on felt and other dark coloured, cold roof systems, due to the potential for post application of other finishes to the surface i.e. gravel, solar reflective paint and retrofit insulations, we cannot recommend this application. The post application of such finishes can inhibit some of the beneficial effects of solar gain and can actually lead to some detrimental issues

Currently, we do not have an IAB or BBA certificate for the Vario XtraSafe with full fill insulation below non-breathable roof covering. However, the Vario’s product characteristics have been substantiated by third parties where the Vario KM Duplex membrane has been used as part of the Isover Optima system, which is the first and only internal dry lining system to have gained IAB accreditation. Vario KM Duplex also has a BBA certificate for both the material itself and its use as part of the Isover Optima system.

For further information please refer to the attached documents which include the respective BBA/IAB certificates for the Isover Optima system and further literature on the Vario products.""""""

I can't attached the documents so if anyone wants them send me a PM with your email

Atlantic1

hexosan wrote: »

Any takers on this

hexosan wrote: »

I've looked at knauf omnifit stud earthwool 220mm it has a thermal conductivity of .034w/Mk and a thermal resistance of 6.45w/mk

Isover Metac 220mm has a thermal conductivity of .034w/mk and a thermal resistance of 5.25w/mk

Both are priced roughly the same does the thermal resistance make much of a difference.

You are wrong on this, Hex. The figure you quoted for Metac is for about 180mm thickness I reckon. If they have the same thermal conductivity, they'll have the same thermal resistance. I've checked both sites and each product has almost identical thermal resistance of 6.45/6.47 for 220mm thickness.

You must have misread something.

Links are here..... Hopefully I'm not breaching posting guidelines by putting them up for clarification purposes.

http://www.tidl.ie/files/Isover_Metac.pdf

http://www.knaufinsulation.co.uk/en-gb/products/omnifit/earthwool-omnifit-stud.aspx#axzz3SKHGrmU1

hexosan

Atlantic1 wrote: »

You are wrong on this, Hex. The figure you quoted for Metac is for about 180mm thickness I reckon. If they have the same thermal conductivity, they'll have the same thermal resistance. I've checked both sites and each product has almost identical thermal resistance of 6.45/6.47 for 220mm thickness.

You must have misread something.

Links are here..... Hopefully I'm not breaching posting guidelines by putting them up for clarification purposes.

http://www.tidl.ie/files/Isover_Metac.pdf

http://www.knaufinsulation.co.uk/en-gb/products/omnifit/earthwool-omnifit-stud.aspx#axzz3SKHGrmU1

The one thing I'm sure of is I'm not wrong ��. The mistake lies firmly with their tech dept who quoted those figures to me.

Atlantic1

hexosan wrote: »

The one thing I'm sure of is I'm not wrong ��. The mistake lies firmly with their tech dept who quoted those figures to me.

You can see from the links I posted that they got it very wrong......

hexosan

Atlantic1 wrote: »

You can see from the links I posted that they got it very wrong......

Thanks for the links

Atlantic1

hexosan wrote: »

Thanks for the links

You're welcome. 👍

hexosan

Below taken from the recently published NSAI guidelines on retrofits

http://www.standards.ie/cgi-bin/news/ie/NEW276


6.3.3.3.5 Re-roofing and using a breather membrane Where roof coverings are being replaced the existing felt underlay can be replaced with a breathable roofi ng membrane instead of providing a 50 mm void for ventilation, in accordance with relevant certification. The membrane should be laid taut from ridge to eaves, or side to side. Generally breather membranes should have an additional set of counter battens fixed on top of the rafters, prior to fixing the new tiling battens to allow for drainage and ventilation. The type of breathable roofing membrane should be installed in accordance with the manufacturer’s instructions and any relevant certification and the void between the breather membrane created by the counter batten should be ventilated from eaves to ridge. It may then be possible to fill the majority of the depth of the rafters with insulation, as usually it is only necessary to leave a nominal space between the insulation and the breathable roofing felt.

hexosan

Calahonda52 wrote: »

OP, how does all this fit in with the Tegral eaves and ridge venting system?
Whats the air path?
Doe it not require counter battening?

I have installed a ridge vent strip (supplied by tegral) which is rolled out underneath the ridge tiles before they're installed creating a continuous 5mm ventilation gap at the ridge.