Block on flat closing cavity

Curious Geroge

Hoping someone can tell me if this is right. Second level blockwork complete and I see that the blocklayers have closed the cavity with a block on flat. Is this right ? There is a holicore been placed on top for the attic floor but I thought cavity closers were used for closing a cavity ?

fclauson

Ahhhhhhh Massive thermal bridge

The old way of closing cab used to be using a block - the modern way is to use a fire proof(priory hall!!!!) closure

Get your eng or arch to advise on how to reduce thermal bridge

Curious Geroge

fclauson wrote: »

Ahhhhhhh Massive thermal bridge

The old way of closing cab used to be using a block - the modern way is to use a fire proof(priory hall!!!!) closure

Get your eng or arch to advise on how to reduce thermal bridge

Thought so.. surprised as both the eng and architect are all about energy and air tightness etc..

Carbonnet

Has any body seen a cavity closer with a cert for cavities over 150mm?

Close with block, put 40/50mm pir in there you ll meet the 0,05 psi value requirement and avoid condensation (f factor greater than 0.75)

Quit scaremongering. Simple detail.

fclauson

Could you do a quick sketch of this

Also your calcs need to take into account how the wall ceiling junction is formed

Carbonnet

fclauson wrote: »

Could you do a quick sketch of this

Also your calcs need to take into account how the wall ceiling junction is formed

Every junction, gable, floor, sill, party wall etc etc are all effected by the decision to thermal line or not, to use aerated block or not just the wall ceiling junction.. There are scenarios published by Irish acceptable, English and Scottish accredited. Use the figures quoted there. A return back, traditional used in Ireland with 40 mm closer.

fclauson

Unfortunatky the published acd are woefully inadequate and create cold bridges issues in their own right if you go for the uvales requird by part l

Carbonnet

fclauson wrote: »

Unfortunatky the published acd are woefully inadequate and create cold bridges issues in their own right if you go for the uvales requird by part l

Has anyone re-run the analysis of the acd's to prove this? Have you seen them?

fclauson

Carbonnet wrote: »

Has anyone re-run the analysis of the acd's to prove this? Have you seen them?

This is how bad it is- in Ireland we have had part l 2011 for a while but the ACDs as published are still only to 2008 - if you use what is published you will create liner cold bridges at most of your junctions so 50 mm as prt acd is just not good enough

Carbonnet

fclauson wrote: »

This is how bad it is- in Ireland we have had part l 2011 for a while but the ACDs as published are still only to 2008 - if you use what is published you will create liner cold bridges at most of your junctions so 50 mm as prt acd is just not good enough

The ACDs use a spread of U-values either side of the junction - down to 0.14.
This should cover whats happening under the current part L also?

50mm in a return cavity block will achieve a PSI value better than the 0.05 requirement. And yes I have run it on full 3D accredited software.

fclauson

Carbonnet wrote: »

The ACDs use a spread of U-values either side of the junction - down to 0.14.
This should cover whats happening under the current part L also?

50mm in a return cavity block will achieve a PSI value better than the 0.05 requirement. And yes I have run it on full 3D accredited software.

When you did this what window frame uvalue did you use and how was it fitted into the ope

Additionally did you to an frsi calc to check the temp on the internal surface at the coldest point if the junction

dathi

lads he talking about closing the cavity at the top of wall ye seem to be chating about closing the cavity at windows:D

fclauson

dathi wrote: »

lads he talking about closing the cavity at the top of wall ye seem to be chating about closing the cavity at windows:D

whoops - anyway - you need to do the thermal model on this too :mad:

Look in any house boom time house which has been recently pumped with insulation where the wall U value has improved but due to the loft insulation not coming out to meet that which is in the wall then you have a liner cold bridge all the way along the roof/wall line

The ACDs does not show a block closing the cavity http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad,18751,en.pdf

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