Spray Foam Instalation Pics

Macspower

heinbloed wrote: »

You have a lot of patience Macspower, thanks!

In your last post answering my "loaf-of-bread" question you wrote:



(omparing the vapour/diffusion tighness/breathability of the foam's skin with the skinned foam itself)

I have my doubts about that, although I have not seen any test reports about this issue.

In a different thread in the construction forum you said the skin (if left on) acts as a vapour control, not as a a vapour tight membrane but still as a 'break'. This makes sense to me, the skin being of a more heavy and denser structure would naturally show a different behaviour.

So with several layers of skins integrated in the finished product (the cured foam would match in principle a Swiss role cake!) the vapour transport can't be the same as with the skinned foam on it's own.
And as far as I understand the EN test demands an exact dimension of thickness of the sample. A rugged sample with an unknown size of surface would be useless. Ergo the sample is cut flat.
The certificate concerning the samples being tested are trimmed samples therefore,foam without skin at all. .

Which is nothing special with bio-foam, it is the general way of testing technical foams. Flat surfaces are necessary for the test.

But in-situ foams are different to ready made insulants like panels, boards etc. where the skins are removed prior to delivery. In the (PU-, EPS-board) factory the skins of the foam blocks are removed and the blocks then cut to sheets or boards.
And then send in for testing, once or twice per year, nowadays it could be every month to hold the permit to sell them as building material- I think.

For this type of boards the EN test was developed.
A test for technical foams without skins.

But the in-situ foams do have these skins, can't be installed without them. Except it is shaved away but this works only at the open, visible side.
The foam's contact surfaces can't be shaved. And developes a skin, between foam and contact surface.

Check this out yourself using a teflon coated baking mould or a mould treated with oil or grease(to get out the sample easily).
I know this from crudely moulding canned PU foam on site. A skin developes on the contact surface which is harder, denser than the rest of the sample.



During the lab tests the sides of the samples are blocked to avoid test-vapour escaping from there, otherwise the vapour would be taking the easy short route and leading to false results.
Usually done with plastic tape.

The test sample results are therefore presenting a two-dimensional vapour movement.

So my question:

Is there a special test done for in-situ foams, an acredited standard for the test? Or is the test for the in-situ foam done the same way as the test for the ready-made foam boards?

I remember a discussion a few years ago where this point was discussed in the industry, that there is no particular test for in-situ foams. But I didn't follow the discussion and haven't heard about a new test method being acredited. I might have missed that!

I know that propellant gases (HCFC,CFC, Pentane, Butane, CO2 etc.) used for technical foams do escape much faster from the ready product if the naturally developing skins are removed, after the foams are cut to size in the factory.

And therefore these products, the cut boards, are sealed with skins of for example aluminia foil. Or wax or resin or whatever.
If the foam board's U-value is determined by the gas mixture it contains the installer of these boards is required to seal the cut edges, to create a seal, a skin. To keep the gas in as long as possible.

So sure it is generally agreed that it makes a difference to gas or vapour movement if the skin is intact or not, present or not.


And with the skin intact the in-situ foam takes up less moisture as compared to a 'shaved' sample. As you have said and as I think as well.

But there is more than 1 skin in the finished product, there are several layers of skin ('Swiss cake roll') plus the contact surfaces at the timber and at the HD-EPS board ( or at the roof felt).

Again: thanks for your patience!

Hi again, Sorry fro short response as I'm replying on my phone.. You've lost me a bit with this TBH but I will have a discussion on it with the foam manufacturers and the tech guys and get back to you

sent from windows 7 phone

heinbloed

Here a web page from an Austrian test lab explaining in short how the thermal conductivity test is done in their lab:

http://www.bti.at/GeraetE1.htm

The samples are grinded down to get an exact level surface.

Hence my question how the bio-foam samples are tested (thermal conductivity and vapour transport): with or without skins on them ? With or without layers of skins in them?

sinnerboy

Macspower wrote: »

Q4 Their must be a minimum of a 9.5mm (normally 12.5) plasterboard between the inhabitated area of a structure and the area insulated. In any living area a plasterbord must be used. This is stated in our documentation, certification and all our structural details. The quoted text refers to living areas.. where the attic is not used for living.. ie storage or just empty space the plasterboard is not used.

Here is the full text

4.1 BEHAVIOUR IN FIRE
Although Bio Foam Spray Insulation is not
classified as non-combustible and must be
protected from naked flames and other ignition
sources during and after installation, when used
in the context of this Certificate the increase in
fire loads in the building consequent to its use is
negligible.
The fire ratings to IS EN 13501-1:2007 Fire
classification of construction products and
building elements – Classification using data from
reaction to fire tests, when tested to IS EN
13823:2002 Reaction to fire tests for building
products – Building products excluding floorings
exposed to the thermal attack by a single burning
item are shown in Table 6.
Once installed, the product must be contained by
a suitable lining board, e.g. 12.5mm
plasterboard, with joints fully sealed and
supported by rafters or studs. Therefore, it will
not contribute to the development stages of a fire
or present a smoke or toxic hazard until the
lining is compromised.
Care must be taken to ensure continuity of fire
resistance at junctions with fire-resisting
elements, in accordance with the relevant
provisions of the Building Regulations 1997 to
2009.
Elements must incorporate cavity barriers at
edges, around openings, at junctions with fireresisting elements and in extensive cavities in
accordance with the relevant provisions of the
Building Regulations 1997 to 2009. The design
and installation of cavity barriers must take into
account any anticipated differential movement.

... no distinction is made between living and non living areas.

Macspower wrote: »

The foam has a neutral fire rating ie it does not increase the fire rating of a roof. The rafters are made of timber and and will have a specific fire rating and our foam has a lower fire rating than the rafters therefore not adding to the overall fire risk.. from NSAI cert 4.1.2 Roofs . The use of the product in a tiled pitched roof will not affect its external rating when evaluated by assessment or test to BS 476-3:2004 Fire tests on building materials and structures – Classification and method of test for external fire exposure to roofs. I hope this answers some of your questions regarding our spray foam.

I would not expect the foam to affect fire performance of a roof in the case of external fire exposure . Being

not classified as non-combustible and must be protected from naked flames and other ignition sources during and after installation

I do expect it to contribute , vigorously , to the surface spread of fire internally.

Ergo - there must always be a plasterboard lining and ergo - a vapour barrier.

Is this not so ?

What happens to the foam if you hold a cigarette lighter to it ? A

thermal attack by a single burning item

as mentioned in the text quoted above from the IAB cert

Macspower

heinbloed wrote: »

Here a web page from an Austrian test lab explaining in short how the thermal conductivity test is done in their lab:

http://www.bti.at/GeraetE1.htm

The samples are grinded down to get an exact level surface.

Hence my question how the bio-foam samples are tested (thermal conductivity and vapour transport): with or without skins on them ? With or without layers of skins in them?

I have asked this question on your behalf and will post a response when I get one from the foam manufacturer.. you can contact them directly if you wish

I was informed on my last enquiry that the samples are tested with skin on... but I will enquire again with your detailed post above.

thanks for your patience

Macspower

sinnerboy wrote: »

Here is the full text




... no distinction is made between living and non living areas.




I would not expect the foam to affect fire performance of a roof in the case of external fire exposure . Being I do expect it to contribute , vigorously , to the surface spread of fire internally.

Ergo - there must always be a plasterboard lining and ergo - a vapour barrier.

Is this not so ?

What happens to the foam if you hold a cigarette lighter to it ? A as mentioned in the text quoted above from the IAB cert

I have covered this in detail on another thread here tonight

you are correct and the foam should be covered by plasterboard according to the NSAI certificate and we recommend this. In reality this is not always done..

As to your cigeratte lighter Questions.. this I am an expert on... as I was always the child with the box of matches I have a liking for setting things on fire.. I have tried this several times.. It does not burn on it's own.. If I hold the lighter constantly to it it will blacken and shrink but when I remove the flame it does not continue... much to my dissappointment as a "denis the meance"

Neilw

What happens to the existing insulation on the floor of the attic, I presume this stays in place?

heinbloed

Youtube has a video available showing the installation of PU foam for various insulation jobs on-site, see here:

Here a German PU foam installer's video:

http://www.youtube.com/watch?v=yc_gqJCH4PU&NR=1

Note that the attic installation of PU foam leaves out the installation of boards between the rafters (in the video!).
The installation description tells us to install tulip wood boards between the rafters in a situation as seen in the video.
For the non-carpenters: Brasilian tulip wood is a highly mould resistant type of tropical timber, also called Bahia wood, the latin name is
according to Wikipedia dalbergia decipularis.

This wood would then be diffusion open,the insulation being capeable to 'breath'.