For your comments and edits:
Congratulations John, another excellent piece of work. It might be worth adding some conclusions about prioritising insulation work based on the construction of an *individual* property. Maybe also mention solar gain and how serious air leaks can wipe out insulation gains, and that other factors play a part such as shelter and wind exposure.
When is the John Rumm Book of the House due out?
I think I'm part of the target audience for a project such as this as I'm trying to understand it all. Please could you define your use of 'surface' as to me that is just an area with no depth. "The thermal resistivity of the surface (U) - the more insulating the material, the slower the rate of heat flow."
So far it seems that it is aimed at people wanting to size rads and boilers.
What would be useful to a possibly wider audience, me included is info for building new extensions, where you need to achieve a certain U value such as
0.3. From what I've deduced from various threads it's not a simple matter of determining wall components, adding their U values and what was that about the reciprocal of something? Then there was the matter of the outer surfaces exposed to the air to factor in, well I think so. It all disappears in a mental smog. Also for floor insulation the thickness of say Jablite required depends on the perimeter to floor area ratio.A comprehesive table of U values would be good.
mark
Yes, I see what you mean. I was just looking for a way of saying a "wall" without it being taken to mean only a wall - it could be a floor or ceiling or window etc.
Indeed - as it says in the intro...
Yup - no reason why it can't be used for that... perhaps including some of the target u values from the approved documents may help here.
Sounds like a bit more description on using k values would help - that is current tucked away at the end.
yup - here is where I was hoping some kindly folks would populate this section with more data ;-)
Yup a bit more intro may help here...
It doesn't have the ring of an international best seller does it?
K values (W/mK) of typical building materials:
Asphalt 19mm 0.50 Blocks lightweight 0.38 mediumweight 0.51 heavyweight 1.63 Bricks exposed 0.84 protected 0.62 Calcium silicate board 0.17 Chipboard 0.15 Concrete aerated slab 0.16 lightweight 0.38 dense 1.40 Felt/bitumen 3 layers 0.50 Fibreboard 0.06 Fibreglass quilt 0.04 Glass sheet 1.05 Hardboard standard 0.13 Mineral Wool quilt 0.04 slab 0.035 Mortar normal 0.80 Phenolic foam board 0.020 Plaster gypsum 0.46 sand/cement 0.53 vermiculite 0.19 Plasterboard gypsum 0.16 Polystyrene expanded 0.035 Polyuretane board 0.025 Rendering external 0.50 Roofing tiles clay 0.85 concrete 1.10 Screed 0.41 Stone reconstructed 1.30 sandstone 1.30 limestone 1.50 granite 2.30 Stone chippings 0.96 Timber softwood 0.14 Vermiculite loose 0.65 Woodwool loose 0.11
Hi John
Celotex have an online U value calculator which seemed easy to use is my test drive. Maybe you could put this link on your wiki.
mark
Ta for the list...
(now if anyone can work out how to get the wiki table to format the list with indented sub catagories - even better)
What does the 19mm refer to here?
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