U-Values for Standard Building Materials?

gaelicyoda · 28-11-2009 2:27am #1

Hi All,

This may or may not exist, but does anyone know where you might find u-values for standard building materials for people trying to work out u-values for their building elements? Some kind of repository?

e.g. Standard u-value for things like your bog standard 100mm thick masonary block, an air cavity, hollow core, natural stone, plaster, mortar, plasterboard, rafters, etc.?

For the likes of specific insulation products, then obviously the place to go would be to the manufacturer's website, but for some of the more generic materials as mentioned above, anyone have any ideas?

I've had a look at the builddesk trial version, but I find there to actually be TOO much choice there, and not that easy to pick any one item over another (basically I think it would be easy to generate inaccurate composite u-values by selecting incorrect individual elements).

Also, I noticed in a number of posts where people mention the SEI u-value calculator, but it looks like it's now missing from their website. If this was a downloadable executable (rather than an online tool), does anyone have a link for it anywhere else?

Cheers,
GY.

(P.S. If there is no such thing currently, might it be a good idea for a sticky for people to refer back to? Mods, please comment!)

holdfast · 28-11-2009 9:46am

ask your ber assessor to over it with you and get him/her to right the spec for the plumbing and insulation.

sydthebeat · 28-11-2009 11:11am

gaelicyoda wrote: »

e.g. Standard u-value for things like your bog standard 100mm thick masonary block, an air cavity, hollow core, natural stone, plaster, mortar, plasterboard, rafters, etc.?
)

materials have 'thermal conductivity' (TC) values.

The thermal resistance of the material is the thickness divided by the TC value.

The thermal resistance (R) of a construction is the sum of all the thermal resistances.

The U value is the inverse of this total resistance.

you will find many thermal conductivities here, on page 36:
http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad,19069,en.pdf

calculating u values is not easy.... there are also conventions to be considered. they are contained here:
http://www.bre.co.uk/filelibrary/pdf/rpts/BR_443_%282006_Edition%29.pdf

my advice.... engage a professional (preferably an architectural technician) to calculate your proposed u values....

u valuate here is a good tool: http://www.xtratherm.com/software/software.php

gaelicyoda · 28-11-2009 12:17pm

Bingo - just what I was looking for, thanks Syd.

I will be engaging with a pro at some stage, but I just wanted to work out a reasonable estimation myself to begin with.

Cheers, GY.

Mellor · 30-11-2009 1:25am

sydthebeat wrote: »

materials have 'thermal conductivity' (TC) values.

The thermal resistance of the material is the thickness divided by the TC value.

The thermal resistance (R) of a construction is the sum of all the thermal resistances.

The U value is the inverse of this total resistance.

you will find many thermal conductivities here, on page 36:
http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad,19069,en.pdf

calculating u values is not easy.... there are also conventions to be considered. they are contained here:
http://www.bre.co.uk/filelibrary/pdf/rpts/BR_443_%282006_Edition%29.pdf

my advice.... engage a professional (preferably an architectural technician) to calculate your proposed u values....

u valuate here is a good tool: http://www.xtratherm.com/software/software.php

Pretty much the exact post I was going to make

U-Values for Standard Building Materials?

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