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    • CommentAuthorwoodgnome
    • CommentTimeDec 6th 2013
     
    Does anyone know of a uk supplier of Compacfoam apart from the GBS.
    Need some for thresholds in new build and would like to compare prices.

    Thanks
    • CommentAuthorscrimper
    • CommentTimeDec 7th 2013
     
    I'd be interested to know too ... would like to save the 100e shipping charge from Germany!
  1.  
    Cavalok use it in their "structural" cavity closers. I don't know whether they sell it separately.

    David
    • CommentAuthorscrimper
    • CommentTimeDec 13th 2013
     
    Just got a price for 33 lengths from their head office in Austria ... total of 0.4665 cubic metres ... came to £985 + shipping which would be around £50 I guess. Seems A LOT ... but I don't know really know what to compare it to for a product over here.

    Basic requirement is for something to sit underneath some timber sash windows, straddling the cavity, just behind a stone cill.

    Any cheaper ideas!?!
    • CommentAuthorTriassic
    • CommentTimeDec 13th 2013 edited
     
    Why not cut your own sheets from a block of high density EPS?

    Isover do a high density EPS! http://www.isover.com/Our-solutions/Insulation-materials/Polystyrene-insulation
  2.  
    Extruded polystrene will have a higher compressive strength than expanded (i.e. look for XPS instead of EPS)
    • CommentAuthorscrimper
    • CommentTimeDec 13th 2013
     
    Need correcting if I'm wrong ... (very new to build processes!) ... but aren't sash window hung normally from the sides ... ie. the compressive force below a sash window installed in this way is next to nothing?
    • CommentAuthordaserra
    • CommentTimeDec 13th 2013
     
    I sat my windows on PU foam in the cavity as well as PU foam all around which joins the CWI. Trimmed it off after and then butted up the inner and outer sills to it stuck with MPS sealant.
    • CommentAuthorSaint
    • CommentTimeDec 13th 2013
     
    Posted By: willie.macleodExtruded polystrene will have a higher compressive strength than expanded (i.e. look for XPS instead of EPS)

    Yes exactly Willie there's XPS available in 500kPa and 700kPa compressive strengths so that's around 0.5N/mm2 and 0.7N/mm2 both with a better thermal conductivity than the Compacfoam at that sort of strength, somewhere around 0.029 W/mK
    • CommentAuthorEd Davies
    • CommentTimeDec 13th 2013
     
    Posted By: Saint500kPa and 700kPa compressive strengths so that's around 0.5N/mm2 and 0.7N/mm2
    The “around” here made my smile. Like 500 g is around 0.5 kg. But only very approximately, you understand?
    • CommentAuthorscrimper
    • CommentTimeDec 13th 2013
     
    Thanks daserra ... great stuff ... have found a supplier online which can do 1.2m square sheets of 100mm high density PU foam block for £150 a sheet ... should only need 2 to do the whole building. It seems to have a lot of pattern making applications, and the vendor doesn't really mention insulation as such, but I can't see why I shouldn't be able to use this. It is 96kg/m3 and has compressive strength of 1050kPa ... so plenty tough enough it would seem ...
    • CommentAuthorSaint
    • CommentTimeDec 14th 2013 edited
     
    Posted By: Ed Davies
    Posted By: Saint500kPa and 700kPa compressive strengths so that's around 0.5N/mm2 and 0.7N/mm2
    The “around” here made my smile. Like 500 g is around 0.5 kg. But only very approximately, you understand?

    ED, yes good point, not sure where the "around" came from, I think I was originally going to go Kgf/m2 to add gravitas then got distracted....:sad:
    • CommentAuthorowlman
    • CommentTimeDec 14th 2013 edited
     
    Posted By: Saint..............Yes exactly Willie there's XPS available in 500kPa and 700kPa compressive strengths so that's around 0.5N/mm2 and 0.7N/mm2 both with a better thermal conductivity than the Compacfoam at that sort of strength, somewhere around 0.029 W/mK

    I use it as in floor insulation under concrete, but do you think if you shaped it, tanked it, with something like a tanking slurry to create a key, you could then skim/render it to create a shaped plaster form that would take weight, with a timber tread on it,- steps for instance? Just an idea.
    • CommentAuthorwoodgnome
    • CommentTimeDec 14th 2013
     
    Are you able to fix the XPS the same way as the Compacfoam? I need to drill and bolt the compacfoam to the edge of my slab as support for doors and sliders.
    • CommentAuthorSaint
    • CommentTimeDec 15th 2013 edited
     
    Posted By: owlmanI use it as in floor insulation under concrete, but do you think if you shaped it, tanked it, with something like a tanking slurry to create a key, you could then skim/render it to create a shaped plaster form that would take weight, with a timber tread on it,- steps for instance? Just an idea


    Just remember the tanking product shouldn't be oil based, the XPS will "melt"
    As for coating it with a render type product for external use there are several companies that make replacement sills and the like with EPS coated with a reinforced cementitious skin but for higher tougher specs they'll use XPS
    • CommentAuthorowlman
    • CommentTimeDec 15th 2013
     
    Yes, it was the XPS I was thinking of.
    I have a couple of interior steps up, to create in either side of a split level room. I thought of making them with serpentine shaped risers and normally I'd use timber and plywood to create the basic form. It just occurred to me though that they may look nice plastered with oak treads. and instead of using a thermo-crete type block for the basic form, this stuff may be easier to shape. Getting the plaster/render to stick would be the problem, some sort of scrim base may be a solution.
  3.  
    Posted By: woodgnomeAre you able to fix the XPS the same way as the Compacfoam? I need to drill and bolt the compacfoam to the edge of my slab as support for doors and sliders.
    I don't know of any other insulation which will take a fixing of this type. If you use XPS then you'll need to put it in a pultruded fibreglass channel or box.

    David
    •  
      CommentAuthordjh
    • CommentTimeDec 17th 2013
     
    Posted By: owlmanGetting the plaster/render to stick would be the problem, some sort of scrim base may be a solution.

    For EWI, mesh is commonly used over EPS, and I think XPS too. Even chicken wire can work.

    Posted By: davidfreeborough
    Posted By: woodgnomeAre you able to fix the XPS the same way as the Compacfoam? I need to drill and bolt the compacfoam to the edge of my slab as support for doors and sliders.
    I don't know of any other insulation which will take a fixing of this type. If you use XPS then you'll need to put it in a pultruded fibreglass channel or box.

    When boatbuilders want to take a high load in a soft area like a balsa or foam core, the trick is to scoop out a larger area to spread the load and then fill it with epoxy plus filler. It has to be said that these are usually sandwich panels and they do leave as much of the skin in place as possible. But using resin-filled holes is commonly used in soft building materials too, so it might be worth trying with XPS, depending on how much the load is.
    • CommentAuthorCav8andrew
    • CommentTimeDec 19th 2013
     
    Purenit by Puren should match the properties of Compacfoam. We have used it for our engineered windows and it is a great material to cut, machine and bond (to timber). We purchased from E H Smith Sustainable.
  4.  
    Resurrecting this thread as we are looking at thresholds and, thermally at least,

    Posted By: Cav8andrewPurenit by Puren should match the properties of Compacfoam.


    this isn't quite true. The compacfoam gets a better lambda value (0.046 for CF200) against Purenit (0.087) for example.

    What I'm struggling with is how to know which section profile to use below our triple glazed sliding doors and windows.

    Purenit give their compressive strength in MPa, whereas Compacoam talk about Compression stress in N/mm² at 2 & 10% compression and allowable stress etc. The Internorm installers have told me that they can remove the standard purenit section that the threshold comes with and fix directly into a compacfoam ground instead. Since our windows are sitting out in the insulation zone, this makes sense as we can pre-fit the compacfoam in advance.

    The GBS sell 100mm wide lengths at 50mm, 75mm and 150mm depths. My feeling is the 75mm should be more than enough, but it would be great to confirm this with some numbers.

    Has anyone here had any experience with this approach or found some equivalent properties?
    •  
      CommentAuthordjh
    • CommentTimeOct 12th 2017
     
    Posted By: Doubting_ThomasPurenit give their compressive strength in MPa, whereas Compacoam talk about Compression stress in N/mm²


    1 Pa = 1 N/m² so 1 MPa = 1 N/mm² (ask google if you don't trust me :)

    The Internorm installers have told me that they can remove the standard purenit section that the threshold comes with and fix directly into a compacfoam ground instead.

    I don't know what 'the standard purenit section' is. Is it a simple rectangular section? What size is it?

    I understand why you might want Compacfoam/Purenit underneath a door threshold (what is the threshold itself made from?) but why do you want it underneath the windows? Why not mount the windows directly in the main insulation?

    Some drawings would help me understand, for one. I don't understand why the depth (=height?) is arbitrary? Why isn't it determined by the geometry?

    You understand that 2% of 75 mm is 1.5 mm - I wouldn't want that much movement in my threshold, for example, so what's the actual load and strain under the threshold?
  5.  
    Posted By: djhI understand why you might want Compacfoam/Purenit underneath a door threshold (what is the threshold itself made from?) but why do you want it underneath the windows? Why not mount the windows directly in the main insulation?


    Sorry I should have explained, generally windows will be supported in a timber 'picture frame' arrangement but the doors are in the same zone. I'm not proposing to use the Compacfoam everywhere, just at ground level where frames would otherwise bear onto the softer below-slab insulation.

    With all credit to Internorm and Isoquick respectively, I've attached a side by side of their details. From what I can make out (there's no direct label) the striped blocks below the extrusion profile on the B&W detail are purenit.

    Scaling that detail based on the threshold profile, I've managed to extrapolate that the purenit bits are about 140mm deep so it looks like I ought to plump for the 150mm depth Compacfoam to be safe...

    Posted By: djhwhat's the actual load and strain under the threshold?


    Not quite sure how I work that out, but what I do know is Purenit has a compressive strength of 7.1 MPa. Compacfoam 200 has
    Average stress at 5%: 2.56 N/mm2
    Average stress at 2%: 1.91 N/mm2
    Modulus of elasticity in linear-elastic range (E-Module): 102 N/mm2
    Recommended stress level (under service load): 1.01 N/mm2

    Are you asking how heavy the doors are likely to be? I'm going to try and get that confirmed this week.
      ThresholdDetails.JPG
    •  
      CommentAuthordjh
    • CommentTimeOct 14th 2017
     
    Posted By: Doubting_ThomasWith all credit to Internorm and Isoquick respectively, I've attached a side by side of their details. From what I can make out (there's no direct label) the striped blocks below the extrusion profile on the B&W detail are purenit.

    Thanks for the drawings but they are too small to read.

    And yes, you need to find out how heavy the doors are and how much of that weight is supported by the threshold (could be any proportion from 0% to 100% depending on the type of door). Then use that weight to work out the stress, check that it is within the working limit, and calculate the resulting strain and use that to adjust levels if necessary. Hopefully the strain is near enough zero to ignore.

    Who suggested the Compacfoam CF200, as opposed to 100, 150, 300, 400? Whoever that is, I'd check with all the other professionals involved that they're happy for that person to design the threshold and just go with whatever they say.
    • CommentAuthorgravelld
    • CommentTime6 days ago
     
    Posted By: djhI understand why you might want Compacfoam/Purenit underneath a door threshold (what is the threshold itself made from?) but why do you want it underneath the windows? Why not mount the windows directly in the main insulation?
    Do you mean using brackets, or a plywood box? Using Compacfoam looks easier than the latter. Might also be more secure than the former for larger glazing expanses?
  6.  
    OK,

    Got some weights...

    The entrance door is 1m wide and weighs 81kg
    Sliding door is 2.6m wide and weighs 260kg plus an 88kg sliding leaf
    Full height window is 1.7m wide and weighs 127kg

    Whilst the entrance and window are both on hinges (i.e. distributed load), I'd expect the sliding door to bear down solely on the threshold so it's probably the worst case scenario.

    So if I understand

    Posted By: djhAnd yes, you need to find out how heavy the doors are and how much of that weight is supported by the threshold (could be any proportion from 0% to 100% depending on the type of door). Then use that weight to work out the stress, check that it is within the working limit, and calculate the resulting strain and use that to adjust levels if necessary. Hopefully the strain is near enough zero to ignore.


    Stress = applied force / cross sectional area

    348kg = 3413 N and the cross section is 0.15d x 0.2w = 0.03m²

    Stress = 113757 N/m² or 0.113757 N/mm²

    The 'elastic modulus' is apparently 2% from elsewhere on Compacfoam's website, but I don't know if this is Young's modulus or how to get from this to the strain. Is it just 0.11/0.02?

    If so it would be 5.7 and nowhere near zero...

    Help!
    • CommentAuthorgoodevans
    • CommentTime4 days ago edited
     
    We need bigger pictures please - can you separate the two pictures above and do two posts - that way each will be 600pixels wide.

    I thick that 2% number indicates the deformation the foam can take and still remain elastic (i.e. not permanently deformd) - if that is true elsewhere on the site gives you a stress limit to remain in that 2% deformation limit. the Youngs modulus would be that stress divided by 0.02 i.e. cf200 the 2% compressive load is 1.91 N/mm2 which indicates a YM of 95.5 N/mm2

    Caveats - the is no info on tensile properties - so bending behavior is not known, and EPS will suffer from so creep keep well within the 2% deformation load.

    I can't make it out but there seems to be a big angle bracket fixed to the ground and supporting the foam this will be a big thermal bridge removing the advantage of the compacfoam - post a bigger picture and I'll be able to comment further.
    •  
      CommentAuthordjh
    • CommentTime4 days ago
     
    Posted By: Doubting_ThomasWhilst the entrance and window are both on hinges (i.e. distributed load)

    The door and presumably the window are fastened to and supported by the jambs at the side, not by the threshold. In particular, the jamb at the hinge side carries all the weight.

    Stress = applied force / cross sectional area

    348kg = 3413 N and the cross section is 0.15d x 0.2w = 0.03m²

    0.15d x 0.2w doesn't sound right. It should be the width of the door times its thickness, 2.6 x 0.2 I presume = 0.52 m²
    So the stress is 3413/0.52 = 6563 N/m² or 0.0066 N/mm², which is way less than the max working stress of 1.01 N/mm².

    The modulus of elasticity, E, is given at http://www.compacfoam.com/26-compressive-strength.html and for CF200 is 102 N/mm², so the strain = 0.0066/102 = 6.4 e-5 and with a height of 150 mm that gives a displacement of 0.01 mm which seems very tolerably low.

    But what Paul said about the need for bigger pictures of the details.
  7.  
    Isoquick detail
      EM10-Threshold-1400x823.jpg
  8.  
    Internorm detail (note: none of the arrows label the substrate but there's a key at the base that suggests the majority of the threshold is supported on 'THERMOPL' which I'm assuming is the purenit)
      Threshold.JPG
  9.  
    Finally the GBS has a variation on the Compacfoam threshold on their website.

    https://www.greenbuildingstore.co.uk/products/compacfoam-200/#prettyPhoto

    I'd be interested to know people's opinions on the threaded bar - this is presumably necessary to tie it into the slab in case the insulation below deforms. I'm assuming there's more than one flavour of threaded bar on the market, so any tips on what to go for would be welcome too.
   
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