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    •  
      CommentAuthordjh
    • CommentTimeDec 4th 2017
     
    I think Nick was asking about the specific project you posted photos of.
  1.  
    @djh, yes, thanks, I was.

    @Bauwer, ''Sure if you improve U value of your 100 years old home at least by two or three times it helps a lot, as the rate of heat bleeding would be reduced by 2 to 3 times correspondingly''. Yes it does, but if you can improve it by even more it helps even more.
    •  
      CommentAuthorBauwer
    • CommentTimeDec 4th 2017
     
    Posted By: Nick Parsons@djh, yes, thanks, I was.

    @Bauwer, ''Sure if you improve U value of your 100 years old home at least by two or three times it helps a lot, as the rate of heat bleeding would be reduced by 2 to 3 times correspondingly''. Yes it does, but if you can improve it by even more it helps even more.


    Not necessary Nick, especially if you improve traditionally built home with petroleum based non breathable insulation. The key requirement for old stone or brick walls without cavity is breathability in my view.

    Just think about that - the target for 40 years old cavity wall insulation is 0.55 (building reg L1B) clearly you can not (and should not) request a more chalanging target for 100 years old wall design.

    It is like asking a 100 years old car to drive with the speed of a modern car....it just does not make sense.
  2.  
    ''Just think about that - the target for 40 years old cavity wall insulation is 0.55 (building reg L1B) clearly you can not (and should not) request a more chalanging target for 100 years old wall design.

    It is like asking a 100 years old car to drive with the speed of a modern car....it just does not make sense.''

    Hmmm...

    The target for a cavity-walled house is 0.55 because the house has a 50mm cavity which, when filled with 'fluff', gives a U value of .... wait for it ... 0.55W/m2K. The reason, I think, is to avoid a revolt in Middle England.

    With solid-walled houses the starting-point is worse, and the potential result better.

    I do not disagree with you re breathability. I was involved with the EWI of a solid-walled house using 180mm of wood-fibre and lime render. Breathability and a massive reduction in U value (less than 0.22). The '100-year-old car' is doing very well.
    • CommentAuthorgravelld
    • CommentTimeDec 5th 2017
     
    Sorry if I missed this, but what's the lambda (of the Light product)?

    How does it compare in installation costs to stick block (EPS) and render?

    I'm thinking maximum possible thickness (150mm on your calculator).
    • CommentAuthorMarkyP
    • CommentTimeDec 5th 2017 edited
     
    can this render really compete with EPS or wood fibre where there is more than 50mm of additional build up available? How thick can it be built up per coat? 30 or 40mm of insulated render perhaps a good option where you are constrained on external build up thickness for some reason. But as soon as you can get a 40 or 50mm EPS board on the wall the render only option is going to be trumped. Much is made of breathability, indeed Bauwer's webiste says the render is both breathable and dehumidifying! If you really need a very vapour open wall then as mentioned wood fibre/lime will do nicely, but lots of period property out there with a coat of EPS and they seem to be doing just fine. I'd consider a product like this if I had less than 50mm to play with, otherwise I'd be willing to bet EPS or woodfibre will be faster, cheaper to install and achieve a far superior u-value.
    •  
      CommentAuthorBauwer
    • CommentTime13 hours ago edited
     
    Hello Nick,
    Sorry for my slow reply, we are extremely busy with the number of orders at that cold time.

    My comments:
    "I was involved with the EWI of a solid-walled house using 180mm of wood-fibre and lime render. Breathability and a massive reduction in U value (less than 0.22). The '100-year-old car' is doing very well"

    a) 0.22 is declared performance while actual performance could be significantly worse due to links between boards being potential "cold bridges" while Bauwer delivers seamless insulation without a need to link boards.

    b) stone homes have rough walls which must be leveled first before boards application, Bauwer does not require any leveling. Actually Bauwer likes rough wall as it is an additional key. Also Bauwer is the most cost efficient way to level the stone walls as it is light-weight and strong highly breathable material.

    c) if wooden fibre board used internally it could lead to condensation issues.

    d) Bauwer is inorganic and nutrural based on vulcanic sand Perlite while wood is organic material could be impacted by water, etc

    e) Please advise what was the cost per sqm both material and labour. Bauwer material is times more cost competitive:
    https://www.homebuilding.co.uk/how-to-insulate-solid-stone-wall-homes/

    f) the main benefit of lower U value is saving on your energy bill and related carbon emissions. Sure the cost of the project should be balanced with the energy savings and improvement of U value by 3 to 4 times are generally sufficient for vast majority of stone wall customers assuming budget cost of Bauwer insulation.

    I could continue with my bullet points:
    http://bauwer.co.uk/templates/Default/images/Leaflet.pdf

    Please do not hesitate to contact me should you require any further information at 0151 558 0890

    Regards, Alexander
    info@bauwer.co.uk
    •  
      CommentAuthorBauwer
    • CommentTime13 hours ago
     
    <blockquote><cite>Posted By: gravelld</cite>Sorry if I missed this, but what's the lambda (of the Light product)?

    How does it compare in installation costs to stick block (EPS) and render?

    I'm thinking maximum possible thickness (150mm on your calculator).</blockquote>

    Honestly speaking EPS should not be used for stone walls traditionally build homes insulation:
    https://www.homebuilding.co.uk/how-to-insulate-solid-stone-wall-homes/

    Bauwer insulation is one of the most cost competitive way to insulate solid stone walls on the market.

    Based on the Building regulations L1B, part 5.12 U value of 0.7 or lower need to be achieved by solid stone or brick walls.
    •  
      CommentAuthorBauwer
    • CommentTime13 hours ago edited
     
    <blockquote><cite>Posted By: MarkyP</cite>can this render really compete with EPS or wood fibre where there is more than 50mm of additional build up available? How thick can it be built up per coat? 30 or 40mm of insulated render perhaps a good option where you are constrained on external build up thickness for some reason. But as soon as you can get a 40 or 50mm EPS board on the wall the render only option is going to be trumped. Much is made of breathability, indeed Bauwer's webiste says the render is both breathable and dehumidifying! If you really need a very vapour open wall then as mentioned wood fibre/lime will do nicely, but lots of period property out there with a coat of EPS and they seem to be doing just fine. I'd consider a product like this if I had less than 50mm to play with, otherwise I'd be willing to bet EPS or woodfibre will be faster, cheaper to install and achieve a far superior u-value.</blockquote>

    Hi MarkyP,
    as I mentioned earlier, not a very good idea using petroleum based EPS insulation for solid stone walls insulation. The reasons are well explained here:
    http://greenbuilding.co.uk/insulating-masonry-walls-of-old-stone-cottages-and-listed-buildings/

    The issues of trapped moisture in traditionally built homes are massive thanks to "experts" or not qualified architects who apply modern impermeable solutions in older buildings.

    Could you please read my post above on wooden fibre boards insulation option.

    We also offer modern insulation systems based on graphite EPS, XPS or stone wool with wide range of robust and flexible fibre reinforced finishes under Vimark brand:
    https://www.vimark.co.uk/linee-prodotti/external-insulation-systems/

    Please do not hesitate to contact me should you require any further information.

    Best regards,
    Alexander
    0151 558 0890
    •  
      CommentAuthorBauwer
    • CommentTime13 hours ago edited
     
    More projects being completed delivering cost efficient solutions.
      Dean Miller.JPG
  3.  
    *My (Nick Parsons') responses to Alexander at Bauwer are prefaced by an asterisk:

    Alexander at Bauwer wrote:

    Hello Nick,
    Sorry for my slow reply, we are extremely busy with the number of orders at that cold time.

    My comments:
    "I was involved with the EWI of a solid-walled house using 180mm of wood-fibre and lime render. Breathability and a massive reduction in U value (less than 0.22). The '100-year-old car' is doing very well"

    a) 0.22 is declared performance while actual performance could be significantly worse due to links between boards being potential "cold bridges" while Bauwer delivers seamless insulation without a need to link boards.

    *Nick P response: Yes, I agree with you that all systems must be installed well. It is a particular concern of mine that some EWI firms leave gaps between insulation boards, or allow thermal by-pass, and cover it all up with the 'icing (render) on the cake'. While a good render finish is important to me, the extremely tight fit of all boards is of fundamental importance.

    b) stone homes have rough walls which must be leveled first before boards application, Bauwer does not require any leveling. Actually Bauwer likes rough wall as it is an additional key.
    *NP response: I agree with you that uneven walls are an issue. Each case needs to be weighed up. In the case I refer to we used a wood-fibre material with a rigid face but with flexible fibre behind, allowing the board to be 'pulled in' over the irregularities we encountered in this specific case.

    Also Bauwer is the most cost efficient way to level the stone walls as it is light-weight and strong highly breathable material.



    c) if wooden fibre board used internally it could lead to condensation issues.

    *NP: My reply referred to EWI - External insulation of External walls. Any improvement to insulation of any wall could potentially lead, through poor detailing or installation or poor understanding of building physics, to condensation issues. In my view that's what fine attention to detail and dynamic condensation risk assessment tools such as WUFI are for.

    d) Bauwer is inorganic and nutrural based on vulcanic sand Perlite while wood is organic material could be impacted by water, etc

    *NP: You are quite right - wood-based insulation can be affected by moisture, and attention to detail, to avoid moisture ingress, is essential. I believe it is essential, though, for pretty well all insulants, even if the material of the insulant itself is not physically affected by water.

    e) Please advise what was the cost per sqm both material and labour.

    *NP: I do not know. I was engaged as a sub-contractor.

    Bauwer material is times more cost competitive:
    https://www.homebuilding.co.uk/how-to-insulate-solid-stone-wall-homes/

    f) the main benefit of lower U value is saving on your energy bill and related carbon emissions. Sure the cost of the project should be balanced with the energy savings and improvement of U value by 3 to 4 times are generally sufficient for vast majority of stone wall customers assuming budget cost of Bauwer insulation.

    *NP: And for those who wish to achieve lower U values other options exist.
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