Hi there,
Our new house will have 180mm of sprayed Warmcell as the external insulation.
However, in the factory, one of the panels was, unbeknown to me, filled with Warmcell and sealed. During the shell erection, the panels got wet, and this one panel has remained very damp at its base. Owning to electrical first fix, I needed to cut a hole and that is when I discovered it was filled, now with very damp Warmcell.
To assist in drying, I have removed the OSB and found that behind, the Warmcell had seriously slumped and compacted at the base. I will be refilled when the whole house is insulated, but I am concerned about the slumping.
I would hate to think that the insulation will slump and I will be left with uninsulated areas in the future.
What is the experience of forum members?
Many thanks in advance,
Rex
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Rex
It occurred this time, I believe, because the panel got very wet during the Jan snow. The Warmcell got wet and its weight compressed it to the base of the panel. If it is not wet, then surely this should not
happen.
Rex
I like cellulose fibre but it needs to be used with full knowledge of its likely limitations.
Tony and Keith - slumping generally seems to occurr when the moisture content is not at the optimum. For example first thing in the morning when the machine starts up and too much water goes in.But it happens early on and can be topped up before boarding. It is generally only in one or two voids. The stuff once dry is almost as stiff as the paper pulp used to make egg boxes. I don't feel gravity is going to compress it enough any more than it will do for comparable insualtion such as glasswool or wool.
There's a load of research into installation of cellulose fiber insulation. The main thing is to get the pressure right when it's blown in place. If it is done correctly, and kept dry, then it should not slump. Warmcell should have plenty of data on this and it should inform the performance specifications they can provide.
Mark
I will talk with Excel about this, but of course, they are likely to say there should not be a problem.
The one panel was probably filled dry int he workshop, but wet entered during the snow and rain when we only had the gf panels standing vertically.
The panels are all PanelLine (or is it Vent?) on the outside, so should be breathable.
Some of the panels have a have structural noggin so the possible slump height is about 1.2m, but many do not. Am thinking of fitting a few noggins (2x1) to give something for the Warmcel to 'sit' on.
Our Warmcel will be 180mm deep, damp sprayed. I am not too concerned about the damp spraying, since there is a difference between damp and wet!
Rex
I'm sorry to hear about your problems with Warmcel. In our experience on building sites and when tested by external institutes such as TRADA, Warmcel doesn't settle when exposed to extreme levels of climatic humidity or vibration as long as it is installed within the guidleines set out in our manuals.
The key to optimum performance is that Warmcel should be installed to the correct density, whilst ensuring the panels don't get soaked in the rain.
Your comments regarding the difference between damp spray and wet are indeed correct. Warmcel can cope with damp conditions due to its breathable properties. Indeed, the damp spray application technique works well and studies performed in the Building Research Establishment (BRE) hygrothermal chamber have consistently demonstrated that the panels dry to below the maximum moisture threshold for timber within 30 days of closing off the panel with a vapour control layer. However,Warmcel, like many other types of insulation product should be kept away from exposure to rain.
Warmcel is only sold into the UK for new build timber frame constructions to approved installer.
I hope that this reassures you. Feel free to contact me at any time should you require any further information or assistance.
Many thanks
Neil
Could you use a vibrating poker (a la concrete pouring) to settle the warmcell when it's blown into voids. Would this greatly reduce it's insulating properties or maybe even improve them?
What does the panel think?
Thanks for you comments. I will be going with Warmcell, if for no other reason than all the SAP calculations are based upon it. Change the insulation and everything changes.
The problem I am having right now is two fold. I have 180mm stud to be filled by damp spray. Or so i was told by the t/f manufacturer. But they went into liquidation and I can find no-one who recommends spraying into 180mm. Most recommend 150mm max. So what to do?
I have been advised to board and dry fill, then batten and put the drylining up. This would create a 1" service void which I do not want.
Then there is the issue of a vapour membrane. I was told that the Paneline/PanelVent construction did not need one, so I have not planned for it. But the general consensus seems to be, put one in. Again, what to do?
Your recommendations would be greatly appreciated.
Thanks,
Rex
The problem with this is the number of spaces that will have to be filled by the Warmcell. Additionally, the nature of the t/f construction has so many vertical narrow spaces (5cms), and noggins dividing normal cavities into two, that it would not be possible to inject Warmcell into them, or know where they are once the drylining is in place. Warmcell would require in injection hole in every space and that will be a lot of work restoring.
I have been told by various Warmcell companies that the drying of damp Warmcell is not a major issue; the issue is that the deeper the wall, the greater the difficulty of keeping the Warmcell in place. 150mm seems to be the max that most companies will spray. Excel say that 180mm is just fine if the applicators feel happy with doing it. The company that will be doing it are fine; they say they have done it before (but they would say that , won't they?)
Regarding the service void, although I have plenty of space, I really don't want to loose another 1" all around the house. I'm not against a service void, but all the services are now in place so I would have an empty void for no apparent reason. Additionally, if the dryling board is in contact with the Warmcell, there will not be a void to provide a 'hollow' sound.
To help with drying, I can always hire a dehumidifier for a week or two.
In retrospect (or on the next build!) I would probably go with factory installed Warmcell, service void and inuslate that void. However, the t/f company did inject Warmcell inot one panel (they cannot explain why) and no-one seems to have know about it. During the shell erection, this panel (along with everything else) go wet. As it was not protected, the Warmcell became a giant sponge. I did not know about this until the first fix, which prompt this thread.
Imagine if the whole house had been factory filled and the tops of the wall not protected! Since the t/f company went into liquidation, I would really have been up the creek without a paddle.
The restructured t/f company have told me that it is the shell erectors who should protect the tops of the panels from rain, but I don't know who is passing on the responsibilty. As it is happens, I only had one wet/dam panel, no big deal.
Rex
But I have a solution. With all the excess wood around the site, I am cutting noggins from bits and pieces and nailing them about mid-way. Not the full 180mm deep to reduce cold bridging, but sufficient to give the top half of the Warmcell something to support itself.
Rex
very interesting thread. I have seen slumping on damp sprayed warmcel into 150mm voids. It was the fist void they sprayed in the morning and there was a little too much water in the mix. The installer offered to come straight back and sort it out. It happened straight away and you could feel that warmcel was looser and wetter. All the other voids stayed put and felt hard to the touch as they dried. It's a pity that a very good product has got this reputation and I think unfairly so. As your experience shows if the whole panel gets soaked there;s not much anyone can do and I agree that pre-filled panels are problematic in our climate unless the whole set up can be protected (unlikely). Sounds like you have found a good simple solution to ease your fears.
Why can't you blow in dry warmcell?
The alternative is to dry line first and then dry fill. But to do this, each vertical drop needs a 100mm hole bored through the dry lining and in the average timber frame house, that will be A LOT of repair work.
Many of my panels have noggins, so that would mean two fill points for a 600mm width. Additionally, dry blowing Warmcell this way, it is not possible to see if all the voids are filled.
My t/f structure has many vertical studs, some of them have a gap of only a few cms. Wouldnever be able to get dry blown in.
Rex
Locomotive fire standards are exceptionally tough. BS 6583 in many countries, M1 in many more. Can't see cellulose meeting those regs?!
The fire tests for passenger trains require passes in surface spread of flame, fire propagation, smoke emission and toxicity, I imagine it would struggle on all 4