Spray PUR foam. Why isn't it popular?

[Onoff]

30 minutes ago, Patrick said:

In regards to the Topic, I can just assume that it partly isn't more popular because of Health issues. Maybe not a problem for many, but it definitely put me off. It is just not tested long enough, specially the icynene type, to tell the long term effects. I was looking into it for quite a while because I found it a very good idea to sprayfoam the entire house, but there aren't any independent studies for long term effects out yet. University of Toronto doing one at the moment but this is to be released in the further future. There are chemical analyses of the foam which suggest that its PROBABLY alright, but I wouldn't want to rely on a probably. Asbestos used to be absolutely brilliant, one of the best materials you could imagine. Until a few decades later. And now it's just official poison. Might be just overly cautious but I didn't want to risk it.

 

There was a thread on here somewhere ref the off gassing of such materials I think. I'm sure MVHR helps greatly in getting rid of that "new build" smell and any accompanying nasties. Not sure though I'd want to live in there if it was noxious. Guess earth wools and cellulose are friendlier in that sense.

[scottishjohn]

6 hours ago, Patrick said:

In regards to the Topic, I can just assume that it partly isn't more popular because of Health issues. Maybe not a problem for many, but it definitely put me off. It is just not tested long enough, specially the icynene type, to tell the long term effects. I was looking into it for quite a while because I found it a very good idea to sprayfoam the entire house, but there aren't any independent studies for long term effects out yet. University of Toronto doing one at the moment but this is to be released in the further future. There are chemical analyses of the foam which suggest that its PROBABLY alright, but I wouldn't want to rely on a probably. Asbestos used to be absolutely brilliant, one of the best materials you could imagine. Until a few decades later. And now it's just official poison. Might be just overly cautious but I didn't want to risk it.

If you air tight barrier is good --won,t be problem anyway -as nothing can get through it.

If it can your barrier is crap !!

Edited May 19, 2019 by scottishjohn

[scottishjohn]

6 hours ago, Patrick said:

In regards to the Topic, I can just assume that it partly isn't more popular because of Health issues. Maybe not a problem for many, but it definitely put me off. It is just not tested long enough, specially the icynene type, to tell the long term effects. I was looking into it for quite a while because I found it a very good idea to sprayfoam the entire house, but there aren't any independent studies for long term effects out yet. University of Toronto doing one at the moment but this is to be released in the further future. There are chemical analyses of the foam which suggest that its PROBABLY alright, but I wouldn't want to rely on a probably. Asbestos used to be absolutely brilliant, one of the best materials you could imagine. Until a few decades later. And now it's just official poison. Might be just overly cautious but I didn't want to risk it.

asbestos is still alright --if you do not disturb it making dust 

over boarding and sealing is quite often done to old asbestos panels --used to be used in plaster amongst other things,so if you knocking down an old plaster coated wall --you might want to damp it down just in case +wear  masks

[Ed Davies]

13 hours ago, scottishjohn said:

If you air tight barrier is good --won,t be problem anyway -as nothing can get through it.

If it can your barrier is crap !!

 

But aren't these foams intended to be the air barrier?

[joe90]

Is it not true that all foams are a petro chemical (oil) product ? Therefore not “green”. I would prefer cellulose (re cycled newspaper). I like (in theory) the idea of wet spraying cellulose into panels in a timber framed house. It’s a shame that in this country you cannot hire cellulose pumping kit like you can in the States to do a DIY job.

Edited May 20, 2019 by joe90

[scottishjohn]

1 hour ago, Ed Davies said:

 

But aren't these foams intended to be the air barrier?

the man was worried about off gassing of the foam 

 

[scottishjohn]

1 hour ago, joe90 said:

I like (in theory) the idea of wet spraying cellulose into panels in a timber framed house. It’s a shame that in this country you cannot hire cellulose pumping kit like you can in the States to do a DIY job.

I don,t like the sound of "wet " when its to do with old  shredded newspapers --thats called paper mache !!

and wet +wood+ paper and our climate sounds like mold to me

 

[joe90]

Perhaps I should have said damp! https://www.greenbuildingadvisor.com/article/insulating-with-damp-spray-cellulose just found this as an example.

[Jeremy Harris]

5 minutes ago, scottishjohn said:

I don,t like the sound of "wet " when its to do with old  shredded newspapers --thats called paper mache !!

and wet +wood+ paper and our climate sounds like mold to me

 

 

It works fine, and is well-proven:

 

 

[scottishjohn]

so how long before you can cover it in ?

that is not the same as blown cellulose where you put a plastic barrier up first and fill through hole ,so must rely on being open to dry out

[Jeremy Harris]

The stuff dries out in a day or so, ends up being a solid block much the same as the pressure-blown dry fill cellulose, but doesn't need the pressure blower and is quicker to install as it doesn't need holes to be cut in an inner skin, that later have to be covered over.

[epsilonGreedy]

32 minutes ago, scottishjohn said:

I don,t like the sound of "wet " when its to do with old  shredded newspapers --thats called paper mache !!

and wet +wood+ paper and our climate sounds like mold to me

 

 

A belief I have harboured for a year but never been brave enough to post in this place.

[Jeremy Harris]

FWIW, I don't think that "wet" sprayed cellulose is used much here in the UK.  Dry, pressure blown, cellulose seems to be reasonably wide spread, though.

[PeterW]

9 minutes ago, epsilonGreedy said:

 

A belief I have harboured for a year but never been brave enough to post in this place.

 

33 minutes ago, scottishjohn said:

so how long before you can cover it in ?

that is not the same as blown cellulose where you put a plastic barrier up first and fill through hole ,so must rely on being open to dry out

 

The blown cellulose stuff with the membranes is exactly the same - just not as wet as this system as it needs to flow and not stick to the walls. 

 

It relies on a couple of products - not just water - that both make it fire resistant and also mould/insect resistant. It used to be a borax based solution but think that has now changed. 

[Ed Davies]

2 hours ago, scottishjohn said:

the man was worried about off gassing of the foam 

 

Obviously. However the foam could be a perfectly good air barrier but still off gas horrid stuff so your assertion that off gassing being a problem implies a crap air barrier is a bit tenuous.

[Dreadnaught]

10 hours ago, JSHarris said:

 

FWIW, I don't think that "wet" sprayed cellulose is used much here in the UK. 

 

 

There is an example at PYC’s new offices in Wales. (They are an importer of WarmCel). The ceiling of their high-ceilinged open-plan office is fully coated with it. It’s a rather unusual and pleasing texture and they intend for it to remain on show. Good for dampening echos too I would think. 

Edited May 20, 2019 by Dreadnaught

[SteamyTea]

I have, in the past, made dozens of moulds for PU.  Once cured, and to the best of my knowledge, there have not been any proven health issues.

This may not be true from incorrect mixes and bad working practices.

There is one very real problem and that is shrinkage.  This happens over many months and sometimes is not obvious.  Every time I see a Panther car I look at the dashboard, and see the gap.  They looked brilliant when they left Harlow in the mid 1980's.

[Jeremy Harris]

13 minutes ago, Dreadnaught said:

 

There is an example at PYC’s new offices in Wales. (They are an importer if WarmCel). The ceiling of their high-ceilinged open-plan office is fully coated with it. It’s a rather unusual and pleasing texture and they intend for it to remain on show. Good for dampening echos too I would think. 

 

 

It's certainly good for sound absorption.  We have dry-blown cellulose and it seems to be exceptionally good at both soundproofing and reducing reverberation, something that quite surprised me, as I expected the plasterboard to pretty much remove any effect that the cellulose would have on that.

[SteamyTea]

3 minutes ago, JSHarris said:

exceptionally good at both soundproofing and reducing reverberation

Was commented on just this afternoon.

[joth]

On 20/05/2019 at 09:30, joe90 said:

Is it not true that all foams are a petro chemical (oil) product ? Therefore not “green”. I would prefer cellulose (re cycled newspaper). I like (in theory) the idea of wet spraying cellulose into panels in a timber framed house. It’s a shame that in this country you cannot hire cellulose pumping kit like you can in the States to do a DIY job.

 

Icynene is castor (vegetable) oil based, not petrol-chems AFAIK?

 

 

On 19/05/2019 at 13:25, Patrick said:

In regards to the Topic, I can just assume that it partly isn't more popular because of Health issues. Maybe not a problem for many, but it definitely put me off. It is just not tested long enough, specially the icynene type, to tell the long term effects. I was looking into it for quite a while because I found it a very good idea to sprayfoam the entire house, but there aren't any independent studies for long term effects out yet. University of Toronto doing one at the moment but this is to be released in the further future. There are chemical analyses of the foam which suggest that its PROBABLY alright, but I wouldn't want to rely on a probably. Asbestos used to be absolutely brilliant, one of the best materials you could imagine. Until a few decades later. And now it's just official poison. Might be just overly cautious but I didn't want to risk it.

 

Been reading up on this a bit:

- Polyurethane contains Isocyanates which are strong irritant / health risk while being applied and if not fully cured (risk if poorly installed).

- If it burns it can emit cyonide which is obviously even worse (aside from the whole "and now your house is burning down" thing).

 

- Icynene has lower VOCs and generally considered safer, but still health concerns linger especially if it isn't cured properly, and if the "closed cell" (vapour impermeable) version is used.

 

 

Context: researching what to put in a cavity wall retrofit; Icynene closed cell has be suggested (by potential contractor) for the extra layer of airtightness defense it provides, but Passive house consultant very against it due to it not ticking the Natural boxes.  I think on a retrofit, we're going to have to accept some unnatural choices, and having it outside our "main" airtight layer (internal OSB) means any lingering badness is mostly kept outside (Edit to add: as @Ed Davies already pointed out above]

The other issue raised is around  breathability  and risk of (condensing?) vapour in the middle of the cavity.... I read so much conflicting info on that my head spins.

 

Edited May 31, 2019 by joth

[scottishjohn]

16 hours ago, joth said:

Context: researching what to put in a cavity wall retrofit; Icynene closed cell has be suggested (by potential contractor) for the extra layer of airtightness defense it provides, but Passive house consultant very against it due to it not ticking the Natural boxes.  I think on a retrofit, we're going to have to accept some unnatural choices, and having it outside our "main" airtight layer (internal OSB) means any lingering badness is mostly kept outside (Edit to add: as @Ed Davies already pointed out above]

The other issue raised is around  breathability  and risk of (condensing?) vapour in the middle of the cavity.... I read so much conflicting info on that my head spins.

 

If you have vcl on inside of it -how  are any vapours going to effect you --the permeable house wrap is allow them to gas off to the outside  over time.

I have been looking at an old granite house and looking for simplest way to get a non permeable layer on inside of the walls ,  the idea is to build a TF inside old walls 

 

closed pur foam is what I have been told by more than one source as the way to seal the old walls -a 30MM layer of closed cell ,as it is a water /vapour barrier it will make any moisture and any "off gassing " in  thewall go outwards through the lime mortar  ,

sprayed in after skeleton of Tf is built(30mm from wall face) ,then insulation of your choice  before closing the new interior walls with air tight membrane

seems this is a common way of dealing with these problems in barn conversions .

icynene close  cell? ,you sure that's not PUR    he was meaning-

still not a DIY job 

[scottishjohn]

On 20/05/2019 at 09:30, joe90 said:

Is it not true that all foams are a petro chemical (oil) product ? Therefore not “green”. I would prefer cellulose (re cycled newspaper). I like (in theory) the idea of wet spraying cellulose into panels in a timber framed house. It’s a shame that in this country you cannot hire cellulose pumping kit like you can in the States to do a DIY job.

maybe an opportunity there  for you?

[joe90]

11 hours ago, scottishjohn said:

maybe an opportunity there  for you?

 

Oh I did look into it and I talked to someone I know in the tool hire business and in his opinion to much work, and risk for a small return in this country.

Edited June 1, 2019 by joe90