125 Slab Edge Insulation

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9 responses to “125 Slab Edge Insulation”

1. How to Insulate a Concrete Floor Slab

   June 6, 2020

   […] Check out this article for a list of slab edge insulation solutions, and episode 125 for my interview with Henry Edney of […]

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2. 

   Robert Potts

   May 30, 2017

   Floor Heating
   If the correct planning is not followed for floor heating design and installation then it should be omitted from the project.
   The building will provide the owner with poor personal comfort and associated high running costs.
   Key points of correct design are:
   1. A structural slab is poured
   2. Walls are built and the roof is constructed
   3. Insulation and thermal perimeter insulation is fitted to all inside/outside walls.
   4. R1.9 insulation is installed on the structural floor. This is required by the NZBC when heating floors
   5. Pipes are laid in circuits for each room
   6. Small aggregate concrete of 90mm is poured over the top
   7. Floor coverings are important. Concrete, tiles and vinyl have 100% efficiency. Timber has a 60% efficiency and
   carpet is rated at 50% efficiency.
   8. Energy source must have weather compensation ability for the modulation of the water temperature pumped
   through the floor. This prevents over/under heating and increases the efficiency of the energy appliance.
   9. This will give the house owner a system that will give them a comfortable house with low running costs.
   10. This method is a European Standard.

   There is a standard EN that we install our floor heating systems to which is a fully thermally broken floor on a room by room basis. Only when this is done the NZBC of R1.9 is acheived.
   It makes no sense that when one room has reached temperature and turns of that the room/s adjacent carry on heating. Thius causes heat transferance

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3. 

   Kara

   April 28, 2016

   12.6C are the minimum to avoid mould growth at 20C indoor air temperature and 50% relative humidity, as this will lead to water activity at surfaces exceeding 80%, which is all that many mould fungi need to grow (in addition to ubiquitous substrate). But: if your indoor relative humidity is >56%, the same is true for 14.4C. So: 14.4C is certainly better than 3.6C, but by no means safe. To achieve safe temperatures at the edge, you either need to put insulation on top of the slab, or cantilever the wall to allow for more insulation around the perimeter. So: Maxraft is on the right track – but there’s still some way to go.

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   1. 

      mcutlerwelsh

      April 30, 2016

      I think that’s a good summary of (parts of) the NZ building industry Kara: “on the right track – but there’s still some way to go”!

      Reply
4. Thermal Mass

   October 27, 2015

   […] the concrete exposed as a useful and comfortable thermal flywheel (with the possible exception of MAXRaft now that they have an XPS option for more rugged edge […]

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5. Concrete Slab Edge Insulation Update

   October 12, 2015

   […] fully insulated slab system (see episode 125 for more […]

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6. 

   ergodesk

   August 11, 2015

   The facts on Polystyrene here are bassackwards, but you are on the other side of the world. That’s all I will say about that.

   Reply
   1. 

      mcutlerwelsh

      August 17, 2015

      Feel free to enlighten and correct us. There’s some confusion out there about polystyrene. I’m interested to know what is backwards.

      Reply
      1. 

         Fabio Parodi

         January 9, 2017

         Hello Mathew,

         My name is Fabio Parodi, I am a CPEng Structural Engineer with an academic
         background in green design. I am cofounder of Cresco Group (www.cresco.co.nz), an international engineering firm with projects on 32 countries.

         There are several drawbacks in using Expanded Polystyrene (EPS).

         ENVIRONMENT:

         (1) especially when used on building sites (where cuts are required) EPS produces small particles very difficult to collect and dispose

         (2) In New Zealand* and Australia EPS still might contain a dangerous chemical called HexaBromoCycloDodecane

         https://en.wikipedia.org/wiki/Hexabromocyclododecane
         https://www.sciencedaily.com/releases/2013/08/130826105752.htm
         https://chemicalwatch.com/45491/european-commission-implements-hbcd-ban
         https://www.wwf.or.jp/activities/lib/pdf_toxic/chemical/newpopsfinal.pdf
         https://www.google.co.nz/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=0ahUKEwjckYmXvrPRAhWGupQKHWpKBt0QFggrMAM&url=http%3A%2F%2Fchm.pops.int%2FPortals%2F0%2Fdownload.aspx%3Fd%3DUNEP-POPS-POPRC6WG-EVAL-HBCD-draftRME-110412.En.doc&usg=AFQjCNE15o5unG_rFlHyJEiqGdb591VzWQ&sig2=zP3Cw15osHi5r5LEBRGU-w

         (3) EPS is uneconomical to recycle (resulting one of the less reclaimed plastic material in many countries – http://www.reclaim.co.nz/productitems.php?id=anytime4908294936a39) and, when contained in a waffle slab, it is virtually impossible to be separated from the other debris in case of demolishing.

         (4) EPS carbon footprint is affected by fuel consumption in freights (typically for a slab with a 180 m2 floor area a 40ft container of EPS is needed).

         PERFORMANCE:

         (1) Insulation: Long term EPS (and XPS) insulation performance tends to degrade. The two primary mechanisms for the loss of R-value of insulations are water absorption and loss of blowing agents.

         (2) Mechanical:
         One of the reasons (maybe the primary reason) of the EPS success is that it is cheap compared to other options. High density EPS and XPS have acceptable (or good) creep performance and therefore they are suitable to bear loads without incurring in long term deflections. Unfortunately, high density EPS and XPS are more expensive than conventional types and only a fraction of EPS used to insulate slabs is high density type…

         (*) New Zealand has a notice of non-acceptance in place for HBCD, which was listed under the Stockholm Convention in 2013. This means that New Zealand will face no obligations towards
         HBCD-containing material under the Stockholm Convention until it chooses to remove that notice.
         There is a voluntary industry accord in place for HBCD which represents an understanding between signatory companies to move away from HBCD towards alternatives. NZ Ministry for the environment is not a party to the accord and does not have the ability to enforce its terms. The NZ Ministry for the Environment is continuing to work with industry to confirm supply settings are right before regulating HBCD which we anticipate will be late 2016 or early 2017. This would include HBCD in building products.

         There are better (and not necessary more expensive) alternatives to EPS. I am happy to provide more information if you like.

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