Is cavity wall construction obsolete, and if so what's the alternative?

Building methods cannot be considered homogeneous.

Inuits live in igloos, mongolians in yurts etc etc. Irish vernacular construction consisted of thick single leaf structures of stone, mud, rubble, horse hair, straw, seaside aggregate etc or anything that was available, handy and cheap. This method isno longer acceptable giving our energy crisis and general health and quality of life understanding.
With the industrial revolution it became possible to build economically with materials such as bricks and blocks. This allowed irish vernacular construction deal with ongoing issues such as rising damp and weather damage by creating a protective second leaf.

However with the looming peak oil crisis and constant rising energy costs, insulation and energy conservation is now the main driver of building methods. As a result, traditional cavity wall construction (4" 4" 4") has been shown to be limited as a solution to the problem.

As a build method it is the most utilised in ireland, apart from maybe cavity block which is still used widly around dublin. This means its is the method that most trades are trained in when serving their time. Its the method most used by established domestic contractors. Also, as a result of more stringent regulations, the concrete industry, the main driver of cavity wall construction, has attempted to react to these regulations in various manners. Cavity wall still has the main advantage of being a very resilient protection against weather.

In my opinion a lot of these augmentations to cavity wall construction are suitable for used as a baseline type of construction for those most financially stretched wanting to provide a dwelling for themselves. Th euse of wider cavities with pumped insulation, or AAC internal block leaf, or even just AAC at dpc level to reduce the thermal bridging. There is now newer type materials which can be used in cavity wall construction to reduce these thermal bridges such as foamglass and rubber.

for those wishing to build above minimum standards i feel cavity wall construction may not meet their brief. How many passive houses are cavity wall?? That being said, newer methods are not the holy grail either. A cavity wall house properly built, with tremenduous attention to detail, will out perform a EWI or Poroton house which isnt built with detail and workmanship in mind. Theres enough threads here and elsewhere debating the pros and cons of all the methods available... .and all the newer technologies as well. At the end of the day there is no substitute to skill, workmanship and buildability.... whether here, Germany or elsewhere. I would purport that one reason german building is looked to as high quality is because, in order to trade as a building contractor, you need to pass a full time college course. Over here all you need to a 4 X 4 and a mobile phone .

Iwannahurl wrote: »

....... but I am not going to post the URL here as I reckon it would probably just be taken as another "business" link and snipped.

yes it would have been !

What point exactly are you trying to make here?

So far i am seeing nothing that hasnt been trashed out many times over here already. If you did a search youd see that that article in CI has been referred to previously.

Alternatives to CW construction have been discussed many times... is this just another rant thread?

Iwannahurl wrote: »

The thread title is self-explanatory, I would have thought.

well, taking that as your main issue then:

1. No, cavity wall construction is not obsolete. See building regulations, accrediated details, Homebond, etc etc

2. The alternatives have been debated many times before and are mentioned in many areas already here.


Maybe your question should be "is cavity wall construction a lesser performing building method than its alternatives?"... now thats a question worthy of debate and one which a lot of the regular contributors here would agree with.

Interestingly, the article you are referring to never claims that cavity wall is obsolete, just that it shouldnt be afforded the "best practise" status it currently has.....
which, ironically, it is fast loosing, by educated professionals, since that article was first published.....

Jonny Harris wrote: »

Hi
I worked as a brick/blocklayer in the UK for quite a while and we ALWAYS built the inner leaf first with 5" aerated blocks and after it had set we would strap the insulation onto the wall and tape the joins. Then build the outer leaf keeping the cavity clean. At the reveals these were filled with strips of PU insulation thus avoiding cold bridging. Easy! I have never seen this method employed over here. You see isulation bats flapping around in cavitys on a lot of sites. I blame the drive by engineers myself!

i have seen examples of this, only in photos. Its an admirable solution to the problem.
Easier just to omit partial fill IMHO