High density insulation

[Russell griffiths]

Can anybody point me at some high density insulation, I’m looking for something to take a high load so I can sit my windows on it, I’m having a good look around but just wondering if anybody had used anything. 

[willbish]

I had a GRP box made up for my front door sill. It's got a ply spine and filled with PIR.

 

Haven't fitted yet so can't be sure it's going to work. But if it does I'll use the same method for the other doors

[ProDave]

26 minutes ago, Russell griffiths said:

Can anybody point me at some high density insulation, I’m looking for something to take a high load so I can sit my windows on it, I’m having a good look around but just wondering if anybody had used anything. 

What windows are these and why do they need something so strong?

 

Mine sit on a 20mm layer if PIR and even before they were fixed in place, the weight of them did not reform it.

[Temp]

51 minutes ago, Russell griffiths said:

Can anybody point me at some high density insulation, I’m looking for something to take a high load so I can sit my windows on it, I’m having a good look around but just wondering if anybody had used anything. 

 

Do you want it to carry the load permanently or just long enough to add fixings? If permanently then i think you want to beware of creep. Eg it might support the load initially but over several years it slowly compresses the insulation.

 

I've never done the sums before but just for fun...

 

Google found some data for PIR in here....see "Continuous compressive stress".. 

 

http://www.react-ite.eu/uploads/tx_mddownloadbox/PP02_Thermal_insulation_materials_-_PP02_20130715.pdf

 

It talks about 40kpa causing 1.5% deformation over 5 years and 2% over 20+ years. So if you had a ground floor window supported on 1m (height) of PIR it would compress 1.5% of 1m or 15mm over 5 years under a pressure of 40kpa. Sounds a lot but the pressure may not be that high under a window...

 

To work out the pressure you would need to know the weight of the window in Kg and the area it rests on.

 

Making up some numbers... Suppose it was a 100kg window resting on a strip of 75mm * 2000mm. The pressure would be..

 

Force/area = 100*9.8/(0.075*2) = 6.5kpa 

 

So might expect a 1m depth of PIR rated for 40kpa to compress 15mm * 6.5/40 = 2.5mm over 5 years.

 

Good enough? 

Edited August 5, 2019 by Temp

[Russell griffiths]

22 minutes ago, ProDave said:

What windows are these and why do they need something so strong?

 

Mine sit on a 20mm layer if PIR and even before they were fixed in place, the weight of them did not reform it.

430kg window, 3.1m long. 

 

So 430 kg divided by 3, so 143kg per m sitting on a frame 90 odd mm wide. 

I dunno am I over thinking this it looks a lot. 

Im not looking forward to moving them. 

[A_L]

55 minutes ago, Russell griffiths said:

So 430 kg divided by 3, so 143kg per m sitting on a frame 90 odd mm wide. 

 

-so about 15kPa, EPS100 with a 1% deformation at around 45kPa would be O.K., perhaps use EPS300 to be safe

 

- here are several possible high compressive strength options

 

foamglas - https://uk.foamglas.com/en-gb/applications/foamglas-perinsul

 

marmox thermoblock - http://www.marmox.co.uk/products/thermoblock

 

purenit - http://en.puren.com/fileadmin/user_upload/products/industrie/purenit/en/Purenit_ENGLISCH_2016_SCREEN.pdf

 

compacfoam - http://www.compacfoam.com/26-compressive-strength.html

 

- none are exactly cheap though.

KayMetzler EPS.pdf

[Conor]

EPS300 will be more than up to the job. Cheap and easy to work with.

[Russell griffiths]

Thanks all. 

[kxi]

For ultra-dense, there's structural thermal breaks like:

Farrat https://www.farrat.com/structural-thermal-break-connections

Armatherm https://www.armatherm.com/thermal-break-materials/

Which presumably you could just use a few blocks of and fill the spaces between with standard non-dense insulation.

 

I assume expensive though.

[scottishjohn]

heres a suggestion 
if you going to sit it on the PIR which is no doubt on top of an ICF wall?

 then how about putting a couple of support screws into the concrete and have them just flush with pir --then if weight gets too much load will transfer 

 i doubt the thermal bridge it could possibly make surrounded by pir is even calculable --but no sinkage 

Edited August 7, 2019 by scottishjohn

[Cpd]

58 minutes ago, scottishjohn said:

then how about putting a couple of support screws into the concrete and have them just flush with pir --then if weight gets too much load will transfer 

Don’t think you want 450kg of window sitting on a couple of screws....... IMHO but I get what your saying ?

[scottishjohn]

Just now, Cpd said:

Don’t think you want 450kg of window sitting on a couple of screws....... IMHO but I get what your saying ?

450kg of window --how big is it ?

 thats one mother on a window ----sounds more like bi-folders than window 

but no problem just put a row of them to spread load --

[Jeremy Harris]

11 minutes ago, Cpd said:

Don’t think you want 450kg of window sitting on a couple of screws....... IMHO but I get what your saying ?

 

 

Definitely not!  The pressure on the bearing area would be colossal, as the screws are so small in cross section.  The key is making sure the window is bearing on enough area to keep the pressure well within the allowable bearing stress of whatever it's sat on.  A couple of large (say, 10mm diameter) screw heads would have a pressure on them, from a 450 kg window, of over 28,100 kN/m². 

[Russell griffiths]

2 hours ago, scottishjohn said:

heres a suggestion 
if you going to sit it on the PIR which is no doubt on top of an ICF wall?

 then how about putting a couple of support screws into the concrete and have them just flush with pir --then if weight gets too much load will transfer 

 i doubt the thermal bridge it could possibly make surrounded by pir is even calculable --but no sinkage 

You are nearly as inventive as me @scottishjohn but not there yet keep trying. 

Going to cut out 90mm diameter holes in the eps, then fit a 90mm fibreglass tube, then replace the bit I cut out into the centre of the tube. 

So in effect I will have little fibreglass load cells every 300mm along length of window. 

[Jeremy Harris]

17 minutes ago, Russell griffiths said:

You are nearly as inventive as me @scottishjohn but not there yet keep trying. 

Going to cut out 90mm diameter holes in the eps, then fit a 90mm fibreglass tube, then replace the bit I cut out into the centre of the tube. 

So in effect I will have little fibreglass load cells every 300mm along length of window. 

 

That will just create a pretty high stress in the limited cross sectional area of the fibreglass tubes.  What wall thickness are they?  I can easily work out the bearing stress and see it it's within limits.  I suspect it might be pretty high, as the CSA won't be very large.

 

Area is your friend when it comes to situations like this.  The higher the load bearing area the lower the stress in the material.  The EPS will be fine on it's own, as it's well within the max allowable bearing stress for even EPS100.  If you wanted to reduce the bearing stress still further then a bit of ply under the window, that's wider than the bearing area of the base of the frame, would spread the load. 

 

If it were me I'd just put the window on the EPS and have done with it.  I have a left over L shaped EPS foundation block here, that's been outside for 6 years now, and which I've regularly used as a step-up.  I weigh about 82kg, and the soles of my feet have a CSA of about 0.02m² each (assuming that they were dead flat - they aren't, as the tread pattern will probably halve this area).  Each time I step on to that block of EPS I'm putting a bearing stress on it of about 40 kN/m².  After years of being repeatedly stepped on and stood on there's not a sign of any depression in the surface.  Your window is going to put a load that's probably less than 1/4 of the stress that my feet put on that block of EPS, and unlike me jumping up and down on it all the time, with luck your window's just going to be plonked on there once.

[Russell griffiths]

@JSHarris I have been doing the, how much does the builder squash the eps when he stands on it test today, all 70kg of me barely puts a dent in it. 

I have been thinking of making a cill pan to go under my windows for extra weather protection and I think this combined with all the side fixings and the strength of the eps itself will be plenty, I think I will be leaving it alone. 

[Jeremy Harris]

6 minutes ago, Russell griffiths said:

@JSHarris I have been doing the, how much does the builder squash the eps when he stands on it test today, all 70kg of me barely puts a dent in it. 

I have been thinking of making a cill pan to go under my windows for extra weather protection and I think this combined with all the side fixings and the strength of the eps itself will be plenty, I think I will be leaving it alone. 

 

 

Sounds a good solution.  My only concern without this would be an uneven point load being applied to the EPS during installation, before the window is sat fair and square down on the EPS.  Putting a tray or pan on top of the EPS will remove that risk and probably make getting the window into place a bit less fraught.

[scottishjohn]

I agree if there were no other areas taking the load --then yes too small --but you already have found it only compresses very small amount -so the full load will never  end up on any one area   ,but shared and anyway i am assuming you have at least 6 other fixing at sides of window which will all take some load , so total downward force will be nothing like full weight 

 

 this cannot be the first time this has been done what is normal solution ?

I have used  2 lumps of 5" phonelic roof insulation as packing blocks under truck  wheel s to get it 10" off ground -- to give space to get under easy  and even with that very small foot print a tyre gives it dented very little even though there would 350 -450kg  on each  of rear wheels 

i think you are over thinking this problem really .

but if want to make something tough 

then use expoxy lay up resin  on grp woven  cloth and lay it directly on the eps in the window holes --  expoxy resin will not melt EPS  as normal grp resin would 

thats what i used to make the wings for the europa aircraft --

 

blue foam cores covered inexpoxy resin+cloth 

 

 

 

[scottishjohn]

4 hours ago, JSHarris said:

That will just create a pretty high stress in the limited cross sectional area of the fibreglass tubes.  What wall thickness are they?  I can easily work out the bearing stress and see it it's within limits.  I suspect it might be pretty high, as the CSA won't be very large.

as i said above there will be sod  all compression really to worry about 

[Jeremy Harris]

9 hours ago, scottishjohn said:

but if want to make something tough 

then use expoxy lay up resin  on grp woven  cloth and lay it directly on the eps in the window holes --  expoxy resin will not melt EPS  as normal grp resin would 

thats what i used to make the wings for the europa aircraft --

 

 

I think we may have met at West Freugh, back in the mid-1990s.  Are you the chap that wanted to do the initial test flights for a Europa there?

[ToughButterCup]

On 06/08/2019 at 07:05, Conor said:

EPS300 will be more than up to the job. Cheap and easy to work with.

 

If you can get hold of it. We needed the shaped EPS 300 for our foundations. 10 week back order....

[scottishjohn]

1 hour ago, JSHarris said:

 

I think we may have met at West Freugh, back in the mid-1990s.  Are you the chap that wanted to do the initial test flights for a Europa there?

that would have been  robert  bolton -king -- our  12000hr+test pilot / type instructor  - or

basil lockwood  -goose  ex aviation engineer -his last working project was concorde  braking 

leader of the  6 man  build group 

yes it was one of the first Europas  to be  home built 

 I got permission to do instrument approachs and touch +go,s --without touching down -- on west freugh when i did my IMC rating training  on a c182 I had use of  ,as  it was closest place that had someone to direct  approach right to ground level by radio/radar --think it was good for them for training as well.

I had to wear "foggles" --which stop you seeing anything but instruments--to simulate full INSTRUMENT CONDITIONS and full aircraft instrument failure .

,turn +slip all covered up ,all you got is rpm and altimeter and  compass

all good fun 

Edited August 8, 2019 by scottishjohn

[Jeremy Harris]

9 minutes ago, scottishjohn said:

that would have been  robert  bolton -king -- our  12000hr+test pilot / type instructor  - or

basil lockwood  -goose  ex aviation engineer -his last working project was concorde  braking 

leader of the  6 man  build group 

yes it was one of the first Europas  to be  home built 

 I got permission to do instrument appriachs and touch +go,s --without touching down -- on west freugh when i did my IMC rating training  ,as was closest place that had someone to direct  approach right to ground level by radio --think it was good for them for training as well.

I had to wear "foggles" --which stop you seeing anything but instruments--to simulate full INSTRUMENT CONDITIONS and full aircraft instrument failure .

,turn +slip all covered up ,all you got is rpm and altimeter and  compass

all good fun 

 

I remember Basil, he was a friend of my Chief Pilot, Dougie (who lived in Newton Stewart), I think. 

[scottishjohn]

yes your  devon pilot often did tree top fly bys above my house --waving at the wife i think  

nice to see an old piston twin being flown other than in a straight line 

[Jeremy Harris]

2 minutes ago, scottishjohn said:

yes your  devon pilot often did tree top fly bys above my house --waving at the wife i think  

nice to see an old piston twin being flown other than in a straight line 

 

He ended up getting into serious trouble for unauthorised low flying after I'd left, as I was asked if I'd be a character witness for his defence.  I had to refuse, as I knew full well that he'd take any and every opportunity to break the rules.  I've flown at a few feet above the water down the length of Glen Trool with him more than once.  I had two Devons in the fleet at West Freugh, XM223 and VP959.  Both were scrapped before I left (they ran out of fatigue life), and were replaced by a Jetstream, XX475.