Advertisement
Help Keep Boards Alive. Support us by going ad free today. See here: https://subscriptions.boards.ie/.
If we do not hit our goal we will be forced to close the site.

Current status: https://keepboardsalive.com/

Annual subs are best for most impact. If you are still undecided on going Ad Free - you can also donate using the Paypal Donate option. All contribution helps. Thank you.
https://www.boards.ie/group/1878-subscribers-forum

Private Group for paid up members of Boards.ie. Join the club.

Wall u value calc

  • 04-01-2021 01:03AM
    #1
    Registered Users, Registered Users 2 Posts: 353 ✭✭


    Hi . My design involves a sand cement render externally on a 100mm outer leaf, 200mm blown bead cavity , 100mm inner leaf with sand cement and skim finish. I attempted a u value calc .. see below.Can you tell me if I am thereabouts or am I missing something...
    seems to me if you could guarantee effectiveness of PIR ie non thermal looping it is a no brainer in terms of u values...
    Appreciate it . Thanks

    Resistance to external surface 0.048 r
    External render - 0.347
    Concrete block outer leaf standard 0.075
    Blown beads 200mm thick at 0.032 conductivity = 6.25 r
    Concrete block inner leaf standard -0.075
    Internal sand cenent and skim - 0.075
    Resistance to internal surface - .122
    Total resistance- 6.99
    U value 1/r = 0.143???
    Thanks


Comments

  • Registered Users, Registered Users 2 Posts: 420 ✭✭Biker1


    Moggaman wrote: »
    Hi . My design involves a sand cement render externally on a 100mm outer leaf, 200mm blown bead cavity , 100mm inner leaf with sand cement and skim finish. I attempted a u value calc .. see below.Can you tell me if I am thereabouts or am I missing something...
    seems to me if you could guarantee effectiveness of PIR ie non thermal looping it is a no brainer in terms of u values...
    Appreciate it . Thanks

    Resistance to external surface 0.048 r
    External render - 0.347
    Concrete block outer leaf standard 0.075
    Blown beads 200mm thick at 0.032 conductivity = 6.25 r
    Concrete block inner leaf standard -0.075
    Internal sand cenent and skim - 0.075
    Resistance to internal surface - .122
    Total resistance- 6.99
    U value 1/r = 0.143???
    Thanks

    Cavity wall.pdf


  • Registered Users, Registered Users 2 Posts: 353 ✭✭Moggaman


    Thanks Biker1.


Advertisement