Spray Foam Insulation

cookie1234

Hi there,
I am just in the process of building a house (237m2), windows go in tomorrow so we are now looking into insulation. We have recieved 1 quote so far for soy based spray foam roof insulation of 5300 Euro for 212m2 roof rafter area. It's much more expensive than I anticipated, and we aren't even on to pumped cavity walls yet. Are there any less expensive alternatives for the roof that are similarly insulative/provide similar airtightness or is this our only sensible option? Any help or advice would be appreciated with regards all our insulation.
Thanks

Declanm5000

What part of the country?
What about air tight membrane?

BryanF

cookie have you looked at some of the other threads on boards.ie about foam insulation (one from the construction forum i mean) you or your arch need carefully read the cert before going ahead...

cookie1234

We are building in Galway. What is airtight membrane is that an alternative to foam? The guy we have got the quote from has a great reputation and he uses BioBased 501s Open Cell Insulation - certified, so we are happy with what will be installed. It's the price that's worrying us! Are there any realistic alternatives to foam that are comparable on airtightness/u-value, but much cheaper? What about good old rolls of insulation between rafters? I have done a bit of reading on boards.ie but have not found an answer yet.

sydthebeat

an alternative depends on an holistic view of the build.

have a read here and maybe do a search on boards.ie to get a general option on the material.

150 mm is offering a u value of approximately 0.253, which is not great.
200mm is offering 0.19 which is more acceptable. what are you being quoted for?

IMO a vapour barrier MUST be used in conjunction with these foams, is this being offered??

BryanF

cookie1234 wrote: »

What is airtight membrane is that an alternative to foam?

may I ask

1. who is looking after your build?
2. who is doing the BER?
3. and who is making sure it is complying with building regulations?

if you don't know what an air tightness membrane is, someone else working for you should! see http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad,27316,en.pdf

cookie1234

Thanks for the information.

Syd - the quote we have so far is for 175mm with a u-value of 0.2. not sure about what barrier/membrane is being quoted for will check up on that.

BryanF - We have been managing the contractors ourselves, but our engineer is overseeing the overall project. He is responsible for compliance with bulding regs and BER. However, he tends to only give us one option when it comes to doing a job. As I said we thought this option for insulation was expensive, so I thought I would do some research myself. I guess I have some reading to do!

In short though are rolls of insulation a viable alternative to pumped foam? Or is it really just a matter of the type of foam you choose?

BryanF

cookie1234 wrote: »

Thanks for the information.

Syd - the quote we have so far is for 175mm with a u-value of 0.2. not sure about what barrier/membrane is being quoted for will check up on that.

BryanF - We have been managing the contractors ourselves, but our engineer is overseeing the overall project. He is responsible for compliance with bulding regs and BER. However, he tends to only give us one option when it comes to doing a job. As I said we thought this option for insulation was expensive, so I thought I would do some research myself. I guess I have some reading to do!

In short though are rolls of insulation a viable alternative to pumped foam? Or is it really just a matter of the type of foam you choose?

look maybe your eng is aware of the ventilation issues and the other cert requirements..
yes there are rolls of several types of insulation available + cellulose & all the poly based products.. your clearly have a learning curve ahead of you, or you could pay your engineer to research an appropriate cheaper alternative:) best of luck, come back and tell us what way you went

cookie1234

Thanks BryanF I certainly do have a learning curve! Could I ask though in your opinion does 5300 euro for 212sqm of pumped foam insulation seem reasonable? I appreciate there are lots of variables you made need answering but a ball park guide would really help.

Carlow52

cookie1234 wrote: »

Hi there,
I am just in the process of building a house (237m2), windows go in tomorrow so we are now looking into insulation. We have recieved 1 quote so far for soy based spray foam roof insulation of 5300 Euro for 212m2 roof rafter area. It's much more expensive than I anticipated, and we aren't even on to pumped cavity walls yet. Are there any less expensive alternatives for the roof that are similarly insulative/provide similar airtightness or is this our only sensible option? Any help or advice would be appreciated with regards all our insulation.
Thanks

Re It's much more expensive than I anticipated
What had you in mind.

What's the rest of the roof structure?

What level of airtightness are you expecting?

why roof insulation as opposed to ceiling?

The following question is somewhat controversial: what does the cert say re fire-rating for the spray: why not post a link to the cert?

BryanF

cookie1234 wrote: »

Thanks BryanF I certainly do have a learning curve! Could I ask though in your opinion does 5300 euro for 212sqm of pumped foam insulation seem reasonable? I appreciate there are lots of variables you made need answering but a ball park guide would really help.

if your figures are correct then that's circa €25 per msq without an air-tightness membrane? or plasterboard? this is a room in roof type job is it? an idea of your floor/roof plan would help as your floor footprint maybe be very different to rafter space being covered... but actually as i said already you need to ask your eng or start ringing around to see whats on offer...I think its a bit high, its also not a low enough U-value for a roof space ... think 0.1 or at least 0.15 w/m2k.. heat rises!:)

cookie1234

Here is the link to the cert -

http://www.biobasedinsulation.ie/insulation/product-certification.php

The foam installer states that there is no requirement for an airtight membrane/vapour barrier as the product is airtight and breathable, and that there is a lifetime guarantee on the product.

I say I thought it was expensive as we have been quoted 2600 for pumped bead cavity wall insulation, for a 150mm cavity, which has a much greater area. Can I compare cost of cavity wall with cost of roof insulation? I'm showing my lack of knowledge again!

Roof is wooden 6x2 joists and slate. There isn't actually much usable space in the attic as the house is a dormer, so I doubt we will use it for anything. I was thinking we may be better to insulate the ceiling as you say then we aren't heating space we don't need to, but like I said our engineer is sending us down the pumped foam route. What would our options for ceiling insulation or where is best to look for this information? Then I can go back to our engineer armed with a little knowledge.

BryanF

cookie1234 wrote: »

Here is the link to the cert -

http://www.biobasedinsulation.ie/insulation/product-certification.php

The foam installer states that there is no requirement for an airtight membrane/vapour barrier as the product is airtight and breathable, and that there is a lifetime guarantee on the product.

I say I thought it was expensive as we have been quoted 2600 for pumped bead cavity wall insulation, for a 150mm cavity, which has a much greater area. Can I compare cost of cavity wall with cost of roof insulation? I'm showing my lack of knowledge again!

Roof is wooden 6x2 joists and slate. There isn't actually much usable space in the attic as the house is a dormer, so I doubt we will use it for anything. I was thinking we may be better to insulate the ceiling as you say then we aren't heating space we don't need to, but like I said our engineer is sending us down the pumped foam route. What would our options for ceiling insulation or where is best to look for this information? Then I can go back to our engineer armed with a little knowledge.

sorry i havent the patients to look for the cert. im very sceptical about 'airtight' and 'vapour barrier' bio foam... + its install requiring roof ventilation and the last one i looked at required plasterboard to comply with certification, are you plasterboarding right to ridge?
here's a link from early today by Beyondpassive, this gives one option of what standard of roof insulation is available:
http://www.boards.ie/vbulletin/showpost.php?p=75033161&postcount=5

still queueing

Hi
I have had foam done on our house and airtight membrane installed.
If you are still in the market PM me and I will tell you who i used and who not to use.
The foam guy is a small operator living in galway with an attention to detail second to none. I can't praise highly enough.
The airtight membrane company who also do insulation based in Tuam / Kilbannon are worse than useless and caused me more hardship and lost me more time. I had 3 weeks of remedial work to do after them fixing holes in the membrane. :mad:

If you need a name for your ground works the guy we had is also fantastic. based in the tuam / shrule / headford area.

Also the plasterers from cloonboo / Roscommon did a fantastic job.

Oh the electrician although he hasn't finished has everything covered from cctv / alarm / elect gates cat5 and hdmi to every TV point. also based in Tuam / Kilbannon.

PM me if you need any details of any of our contractors or to see the work they done / doing.

Waters10

still queueing wrote: »

Hi
I have had foam done on our house and airtight membrane installed.
If you are still in the market PM me and I will tell you who i used and who not to use.
The foam guy is a small operator living in galway with an attention to detail second to none. I can't praise highly enough.
The airtight membrane company who also do insulation based in Tuam / Kilbannon are worse than useless and caused me more hardship and lost me more time. I had 3 weeks of remedial work to do after them fixing holes in the membrane. :mad:

If you need a name for your ground works the guy we had is also fantastic. based in the tuam / shrule / headford area.

Also the plasterers from cloonboo / Roscommon did a fantastic job.

Oh the electrician although he hasn't finished has everything covered from cctv / alarm / elect gates cat5 and hdmi to every TV point. also based in Tuam / Kilbannon.

PM me if you need any details of any of our contractors or to see the work they done / doing.

Hi Still,

Would appreciate if you could forward foam installers and typical things I should be looking for, i.e typical price for a roof approx. 316 sq meters. Also when spraying onto the breathable felt and not using vent cards ..should I be concerned.
Why did you chose to go belts and braces with additional air tightness and use of membrane and foam?

Thanks

still queueing

<snip>
Sorry I can quote you for someone elses work.
Give <snip> a ring he'll call out and measure up and quote you.
Re vent cards certain types of foam need card others don't.
<snip>can advise you there too.
Reason I went with belt and braces is because I am never going to get a second chance at it and even if the spray foam fails air tightness in 10 - 20 years I still have the membrane.

Just got our heating on last week. Cant say how good things are yet as its still drying out from the screed so heat on and all windows open...:eek:.


Snipped: Sydthebeat

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