Any experience with cavity block (aka hollowblock) pumped insulation?

Spndlewick

I have noticed a small number of companies are now offering the pump foam insulation into 9 inch cavity block walls (sometimes called hollowlock walls).  When I last looked into this, the prevailing wisdom was that it was pointless, due to the construction of the walls meaning there were thermal bridges every few inches.  This is distinct from a cavity wall, made by having a gap between two cinder block walls.  However, the cost is SIGNIFICANTLY less than external dry lining (1500-2000 Euros as compared with 12,000 to 15,000 Euros).  The websites for these companies do not claim that the solution is as effective as it would be in a cavity wall, or as effective as external dry lining, but state that (I'm paraphrasing here) about 75 to 80% of the wall will be filled, you will still see a noticeable improvement.
I'm aware the SEAI doesn't offer grants for this, and I think they explicitly discourage you from doing it on their site, and I've seen plenty of threads here where people have voiced strong opinions about this (generally, that it's useless and a scam).  Perhaps it is, and if so, fair enough. But what I am curious to know is, is there anyone on boards who has had the cavity block insulation done, and if so, did you notice an improvement and were you happy with it?

Roadtoad

Consider the €1500-2000 a discount on the €12000-15000 spend, i.e. do not do it, but invest the money into the bigger fund.

There is way too much bridging, and far too many cavities.

Spndlewick

Thanks, have you had it done?

Gumbo

They would have to drill every block twice, yeah?
I suppose the thermal bridging may be helped if you already had internal insulation such as insulated boards or wool between battens?

Many houses built with brick fronts had cavity blocks (hollow blocks) as their side fable and rear. These were then all fitted internally with board or wool.

Maybe someone can do the tech figures of that would help?

sydthebeat

Snake oil

Metric Tensor

Even if they were able to fill each void the result, in my opinion, would be quite poor and possibly not worth the outlay.

But I cannot see how they can claim to fill each void. There are usually two separate hollow sections in each block and the blocks are also staggered. Add to this the fact that the mortar between the blocks will have been in no way laid to try to ensure continuity between voids. It will almost certainly have been lathered on and spilled and dropped all over the shop.

I'd be very interested to see thermal imaging photographs of previous jobs.

sydthebeat

Filling the voids makes the situation actually worse.

There have been studies on this.

Lumen

Spndlewick wrote: »

external dry lining

Spndlewick

Sorry Lumen, I mean external wall insulation, I've just gotten into the habit of calling it that.
Thank you for the replies, but does anyone have any personal experience with this, or even know someone who does?  I'm afraid my researches (i.e. Googling :-) ) haven't turned up any personal experiences with it, and obviously the companies who supply it are going to speak positively about it.

DOCARCH

sydthebeat wrote: »

Snake oil

+1

It's a sham.

gctest50

Those holes in the middle are for filling with rebar and concrete ?

gctest50

,

Gumbo

gctest50 wrote: »

Those holes in the middle are for filling with rebar and concrete ?

Generally no.
They can be utilised like that in specific locations on larger builds such as schools or warehouses, but in a general dwelling, they will not be filled with anything.

Metric Tensor

As per kc above - only filled in unique and relatively rare circumstances usually coinciding with vertical tying for disproportionate collapse in large masonry structures. Not something you encounter in your "average" house.

In addition - it's can be quite useful in tall garden wall scenarios!

dathi

Spndlewick wrote: »

Sorry Lumen, I mean external wall insulation, I've just gotten into the habit of calling it that.
Thank you for the replies, but does anyone have any personal experience with this, or even know someone who does?  I'm afraid my researches (i.e. Googling :-) ) haven't turned up any personal experiences with it, and obviously the companies who supply it are going to speak positively about it.

http://www.josephlittlearchitects.com/content/breaking-mould-2

some info in this article

Spndlewick

Thank you dathi, that article was very informative, much obliged to you.

Exo

dathi wrote: »

http://www.josephlittlearchitects.com/content/breaking-mould-2

some info in this article

Updated link to the article, for those curious: http://www.buildinglifeconsultancy.com/content/breaking-mould-2.

ravendude

Surely having your house walls drilled like swiss cheese can't be structurally sound either.

zl1whqvjs75cdy

I think the house at the end of my road had this done. Can seem to see the drill marks coming up on the colder mornings. I'll knock in and ask them how they find it. House round the corner recently had the external insulation done too so I'll knock in there and see how they are getting on. Will report back on which is better but I think we all already know the answer here.

sydthebeat

donkeyoaty0099 wrote: »

I think the house at the end of my road had this done. Can seem to see the drill marks coming up on the colder mornings. I'll knock in and ask them how they find it. House round the corner recently had the external insulation done too so I'll knock in there and see how they are getting on. Will report back on which is better but I think we all already know the answer here.

Unless the drill holes are 9" apart.... It won't be what's being discussed here

zl1whqvjs75cdy

sydthebeat wrote: »

Unless the drill holes are 9" apart.... It won't be what's being discussed here

They look about that alright and there's loads of them

Milsey

The op asked for feedback from people who have had it done. Not peoples opinions on wether they like the idea or not. I too would like to hear from somebody that actually got it done and not keyboard engineers.

Gumbo

Milsey wrote: »

The op asked for feedback from people who have had it done. Not peoples opinions on wether they like the idea or not. I too would like to hear from somebody that actually got it done and not keyboard engineers.

Keyboard engineers in a Construction Sub-Forum where most of the regular posters are Architects, Engineers and Surveyors

Might want to start your own thread considering this one started over a year ago.

Calahonda52

kceire wrote: »

Keyboard engineers in a Construction Sub-Forum where most of the regular posters are Architects, Engineers and Surveyors

Might want to start your own thread considering this one started over a year ago.

.
The keyboard engineers are over in the build your own computer section
Another one for the ignore list