Spray foam insulation

[Russell griffiths]

Right running with my other topic, are there many people who have used or considered spray foam insulation @PeterStarck

What sort of thickness was sprayed(average)  

do you have a rough cost per m

are you happy with it ?

did this provide you with an air tight finish ?

god this is getting complicated. 

Russ. 

[Dreadnaught]

And what's the decrement delay of spray foam in comparison with EPS or blown cellulose? A useful question @Russell griffiths?

[bissoejosh]

For Icynene I was quoted £33m2 @ 300mm for an I-Beam roof. For comparison our best Warmcell quote was £23m2 @ 300mm thickness.

 

 

[Gone West]

7 hours ago, Russell griffiths said:

Right running with my other topic, are there many people who have used or considered spray foam insulation @PeterStarck

What sort of thickness was sprayed(average)  

do you have a rough cost per m

are you happy with it ?

did this provide you with an air tight finish ?

god this is getting complicated. 

Russ. 

I had 212m2 @ 350mm thick and 74m2 @ 250mm thick of Icynene which cost £9950. The 74m2 @ 250mm thick was in the ground floor ceiling. This works out at £107/m3 which is a little less than bissoejosh at £110/m3 but in the same ballpark. The installers had never sprayed a thickness greater than 100mm before so it took them a while to adjust. There was a lot of excess foam which I removed and disposed of. Icynene and the external 15mm OSB3 racking were the only airtightness layer used and we had an air test result of 0.47ACH.

 

7 hours ago, Dreadnaught said:

And what's the decrement delay of spray foam in comparison with EPS or blown cellulose?

The effects of decrement delay and whether it is is important in a build requires a lot of thought. It is very difficult to model decrement delay and the effects of heavy shading by trees, windy weather, micro-climate or the construction of the build with vented air gaps in the structure will all have an effect.

We did consider blown cellulose along with other types of insulation but weren't confident all the problems with sagging had been addressed.

[Jeremy Harris]

10 hours ago, Dreadnaught said:

And what's the decrement delay of spray foam in comparison with EPS or blown cellulose? A useful question @Russell griffiths?

 

It's slightly longer than EPS, and a fair bit shorter than blown cellulose.  However, it depends very much on what the outer skin of the house is made from.  If the outer skin is brick, block or stone, then that will substantially increase the overall decrement delay.

 

It's also a bit site-specific.  Our location is such that the house gets sun from sunrise to sunset, so decrement delay has a potentially big impact.  It was one reason we opted to use pumped cellulose.  If we'd had a stone outer skin than I'd not have been so concerned, and may well have opted for something like PIR insulation.

[willbish]

On 21/09/2018 at 17:05, PeterStarck said:

Icynene and the external 15mm OSB3 racking were the only airtightness layer used and we had an air test result of 0.47ACH.

 

Hi Peter, was the OSB you used the T&G variety with joints glued or was a butt joint sufficient?

 

I'd also like to do away with an airtightness membrane and go for Icynene but cant afford to do both! Therefore I need to ensure a solid airtight score from the Icynene and sarking.

 

[Simplysimon]

and don't forget any chemicals and offgassing which blown cellulose won't have, is recycling important to you?

[Gone West]

15 hours ago, willbish said:

 

Hi Peter, was the OSB you used the T&G variety with joints glued or was a butt joint sufficient?

 

I'd also like to do away with an airtightness membrane and go for Icynene but cant afford to do both! Therefore I need to ensure a solid airtight score from the Icynene and sarking.

 

The OSB3 was square edge and butt jointed. I think that the 350mm of Icynene I have, is the largest contributor to the good airtightness result along with careful detailing around windows and doors. The vast majority of the offgassing happens in the first 24 hours.

[Triassic]

On the subject of Icynene. I have a basement and the engineered metal web joists sit on a ledge forming part of the reinforced concrete basement wall. The level of insulation at this point is poor, so i was considering if sprayed lcynene between the beams, encasing the beam ends, would work?

[scottishjohn]

simple answer   is yes.

my architect did a job in london --conversion of an old big tin shed 30,s design into accomodation .

there was also a hvac system as well as it was multiple occupancy .

it was  fully foamed, all the walls and roof under plasterboard  etc .

when he went to sign it off it was found he could not open doors easily due to vacum in building  when hvac running .

when hvac people were contacted --"AHH you got it better sealed than we expected,never seen one that  good " --so it had to be re-speced to suit.

so yes it will work fine ,cos that was only 150mm they used

Edited January 30, 2019 by scottishjohn

[willbish]

9 hours ago, PeterStarck said:

The OSB3 was square edge and butt jointed.

Thanks Peter, and did you butt the joints up tight or follow the MI's and keep a 3mm expansion gap. Im assuming you didn't bother to tape the joints.

 

9 hours ago, PeterStarck said:

I think that the 350mm of Icynene I have, is the largest contributor to the good airtightness result along with careful detailing around windows and doors

Yes I think the thickness is important, in this demo example spray foam has been used to prove how well it performs at creating an airtight layer, coming in at 1.246m3/h.m2.

The foam is moderately thick, they've used decent backing/sarking throughout and the foam hasn't been trimmed in places which seems to help by not disturbing the joints between foam and rafter.

 

In a recent email Icynene said to me, "we regularly achieve figures better that 1.5m3/hr/m2". If I convert this to AC/H for my whole house the result is understandably poor. Therefore I need to balance the relatively poor airtightness of the roof compared with the good airtightness of the ICF (hoping for something less 0.5m3/h.m2 here, excluding openings)

 

Its hard to quantify how much effect the following have in creating an airtight layer with spray foam:

Thickness of foam

Whether its trimmed back

Type of sarking or backing material

Brand of foam

 

I'm finding it all a bit ambiguous and wondering whether taking the membrane route may be a safer option for a guaranteed <0.6AC/H

[Russell griffiths]

Hi will, in the grand scheme of things, an internal vapour control layer should cost about £3 per m 

could be money well spent. 

[willbish]

Yeh good point, it doesn't add a great deal if paying ~£40m2 for Icynene

[Gone West]

12 hours ago, willbish said:

Thanks Peter, and did you butt the joints up tight or follow the MI's and keep a 3mm expansion gap. Im assuming you didn't bother to tape the joints.

They started off by having the 3mm gap and filling it with PU glue but then changed to butt joints. They didn't tape the joints.

 

12 hours ago, willbish said:

Its hard to quantify how much effect the following have in creating an airtight layer with spray foam:

Thickness of foam

Whether its trimmed back

Type of sarking or backing material

Brand of foam

Yes very difficult to quantify. All I can say is that ours was trimmed back and that Icynene is very different from other types of spray foams I have seen. When cured it is very flexible, rubbery and doesn't crack. A potential problem with Icynene is that it doesn't stick to cold surfaces very well and is therefore best sprayed when the surface temperature isn't too cold. A friend had the walls of an outbuilding sprayed in the winter and the Icynene pulled away from the corners.

[SuperPav]

Reawakening this topic as we're trying to line up a contractor for Icynene (or similar) to fully fill the cavity on our build (stone outer, block inner). Icynene have come back and said only their closed cell (PU) foam is suitable for a masonry cavity application, I mistakenly was planning on open-cell waterblown stuff until this point.

 

More worryingly, they've quoted just a shade under £10k for a 110sqm at 125mm fill, which seems insane? Still waiting for a survey and quote from another installer, but this cost would be a big problem (we budgeted around half that, based on blown EPS being quoted at ~£3.5k). The ties and cavity tray/dpm and airtightness detailing is pretty poor in the house, so we don't really have any alternative to foam insulation at this stage with out a lot of other remedial/additional works to correct the detailing.

 

Has anybody used Icynene or other spray/injection foam insulation recently, and could recommend a contractor? The build is in Gloucestershire...

[SteamyTea]

18 hours ago, SuperPav said:

More worryingly, they've quoted just a shade under £10k for a 110sqm at 125mm fill

Not the cost of the machine, or the materials.

https://m.alibaba.com/product/62219800864/polyurethane-spraying-machine-foam-making-machine.html

[Russell griffiths]

What is wrong with the eps beads, would need to insulate further on the inside as well though. 

[Nickfromwales]

On 31/01/2022 at 23:00, SuperPav said:

and could recommend a contractor

Solarcrest seemed to do a very good job on the last install I saw them do, with a spray on internal airtight layer to take a stone cottage to AT. No experience of them doing a cavity wall tbh.

 

GreenEnergy was down to which team came out. 1st team with them was a disaster, and the very good second team ( sent out to rectify the train wreck the 1st team created ) struggled to retrospectively pull it out of the shit.

Now an expensive compromise, since made better by clients own patching and cutting, and diligent trades on site further reinforcing those works by filling gaps as they go with gun grade ( illbruck 330 ) closed-cell foam by hand. 

[Iceverge]

To reiterate the posts above, I priced this for our house an it was a shade under 4 times the cost of EPS beads. About €18000+Vat IIRC. However that was for a product with no agrement cert. Walltite or Icyene would have been dearer. Not remotely worth it to reduce from a K value of 0.033 to 0.026W/mK.

 

The beads worked fine. Very comprehensive full fill. 

 

In your case you could add a parge course internally and some insulated plasterboard or a battened service cavity if you wanted to bulk up the insulation levels. 

 

If you added a 50mm battened mineral wool insulated service cavity you would get a U value of about 0.21 W/m2K. 50mm of pir backed plasterboard about 0.16 W/m2K.