U Value for old cottage wall

michael knight

I'm trying to estimate a u-value for an old cottage wall. It's roughly 800mm thick, I'm assuming it's made up of a mixture of mud, straw, stone etc. I'd say it's around 100 years old but no way of knowing.
Anyone any ideas??

Jimbo

michael knight wrote: »

I'm trying to estimate a u-value for an old cottage wall. It's roughly 800mm thick, I'm assuming it's made up of a mixture of mud, straw, stone etc. I'd say it's around 100 years old but no way of knowing.
Anyone any ideas??

2.10 W/m2k is the generic U-value give to stone wall of that age of any width in the BER software

michael knight

Thanks for that, but I don't really think you could really call it a stone wall, I'd say there's fairly little stone in it. It's a typical cottage wall that dates back to around the end of the 19th or beginning of 20th Century.

sydthebeat

michael knight wrote: »

Thanks for that, but I don't really think you could really call it a stone wall, I'd say there's fairly little stone in it. It's a typical cottage wall that dates back to around the end of the 19th or beginning of 20th Century.

Preston (1991) reports an evaluation of a cob wall with a U-value of 1.49 Wm-2K-1. Pearson (1992), p.54, reports U-values of 1.12 Wm-2K-1 and 0.67 Wm-2K-1 for cob walls of 300mm and 600mm, respectively.

busman

Hi Michael,

What I think you are referring to is a cob wall
http://en.wikipedia.org/wiki/Cob_(material)

As cob is a natural material and very variable you will find it hard to find a "certified" u-value

One reference that I have found on
http://www.tonygraham.co.uk/house_repair/wattle_daub/WD-5_5.html
which reports it as
"Pearson (1992), p.54, reports U-values of 1.12 Wm-2K-1 and 0.67 Wm-2K-1 for cob walls of 300mm and 600mm, respectively."

Where I'm from in South Wexford this was a very common building material and many cob houses still survive. One in particular near Mayglass was built in the early 1700's
see http://www.mayglass-2000.ie/project.html.

The clay used is locally know as "marl" and many houses have ponds near them called "marlholes" where the clay for the house was dug!

sydthebeat

lol... snap busman!!

great minds.....

busman

sydthebeat wrote: »

lol... snap busman!!

great minds.....

I must learn to type faster!!! :-)