Wednesday, 3 April 2013

Unintended consequences

I don't know why, but this made me smile this morning. 

You may have noticed a newish trend for retro-fitting external wall insulation to blocks of flats; 4" or so of mineral wool batts covered in a coloured render. Not only do they dramatically cut heating bills for those in old solid-walled apartments, they are proving very popular with green woodpeckers. Once they're through the render on a corner, it's short work to create a warm, snug, waterproof home to raise a family in at safe treetop level. And as birds learn very quickly from each-other, these are proving more popular than the harder work of hollowing out a burrow in a live tree.


10 comments:

SadButMadLad said...

They must be some big woodpeckers looking at the size of the holes compared to the balcony.

right_writes said...

The local council should fine them for squatting.

Raedwald said...

I think it's more of a fascia board than a balcony - the size of that conduit is prob 25mm

Peter Ward said...

...then the rats will get in, and the pigeons.

But once the bats take up residence nothing can be done!

G. Tingey said...

Where does the original photo/article come from?
Somewhere in Gramnay, obviously [ "K Heute" ] but more detail would be apprciated....

pjt said...

I am slightly astonished. Does this kind of insulation thing really work in British climate? Up here closer to Arctic circle, that'd be a sure way to get condensed water in the structures, and then you've got mould and fungi growing there, and in a year or two the building is banned by health officials.

Perhaps the English just don't care about a bit of growth in the walls, and if it makes you cough, it's too bad you're such a weak person?

Though I must admit that it's a more polite way of senicide than sending old people to float away on a piece of ice.

Raedwald said...

Greg: http://tvthek.orf.at/programs/70022-Kaernten-heute/episodes/5682647-Kaernten-heute

Item 6 specht-krähen (woodpecker - crow)

Raedwald said...

pjt - the render is vapour-permeable but waterproof, so internal moisture can escape (or. as you suggest, condense in the rockwool layer, where it doesn't do much harm until a spot of sunny weather sweats it out)

The worst system is expanded polystyrene applied externally with an impermeable render on solid brick walls; result is exactly as you suggest

G. Tingey said...

Followed you link.
I LURVE the idea of "scare-crows" being models of crows to keep the woodpeckers out!
Oh, and they are Spotted woodpeckers (probably greater), not green ones!

pjt said...

Interesting - thanks for explaining. Over here (60°N), that kind of structure is not permitted. The outer surface may pass water vapor out but that is not enough, the insulating layer needs to be ventilated in our building code. And allowing significant amounts of humidity in there (e.g. by woodpeckers) is not a good idea.