Anna Kettle wrote:

On Fri, 03 Jun 2005 02:59:52 +0100, The Natural Philosopher
wrote:


Andrew Firebarce are giooid on structural calcs. The BCO will take their
word for it.


Don't know them but will squirrel the name away for future reference.
Where are they based?


Well you know Anna, there are two ways to do things: let the damp in and
arrange for it to get out outwards, or not let it in at all barely, and
let it migrate inwards and have a bit of internal heating and ventilation.

Your way is number one, but I see no problem with modern ways to
insulate/heat/ventilate and put a waterproof skin outside- you need that
anyway to get rid of the water that humans give off.


You got me thinking about the differences between the two building
methods and I came up with

Traditional:
Breatheable
Slightly flexible
Eco friendly ... man

Modern:
Impermeable
Rigid
High embodied energy

Straw bales sit firmly in the traditional zone on the ecofriendly
front, being bio and degradable. On reflection I can't see a problem
using them under an impermeable skin so maybe there is potential for
crossover there, but the design would have to be thought through with
care if they are to be loadbearing cos they will definitely not be
rigid and impermeable is only any good if it stays that way

You see Anna, I am an engineer, and I use whatever is to hand, that's
suitable and cheap.

400 years ago it was oak and wattle and daub and thatch. It looks nice,
but it has structural limitations.


Today we have a huge range of plastics, steels and other materials
available.

I am neither a traditionalist, not a modernist.

I don't like buildings with steel exoskeletons 'celebrating the use of
modern materials' any more than I like a house with no damp proof
course, no foundations, and which absolutely requires a breathable skin
to eradicate the rising damp. ;-)

I suppose if you gave me an unlimited budget I might come up with a
house thatched with carbon fibre :-)

I am by no means sure that slaked lime takes any less energy to make
than portland cement by the way.

Arguably we have more oil left than oak trees as well.

BUT we certainly have a LOT of straw around right now. And its
engineering properties are actually, in large bulk, pretty reasonable
for houses.

As far as breathable/not breathable goes, houses with humans generate
water. That has to be eradicated somehow.

In older houses with lower insulation, the water got to the walls and
condensed, making them damp, and the walls needed to breath outwards to
get rid of it. The walls got damp also because they had no DPC's. They
needed to be flexible because they subsided as they had no foundations.

They got round all that by having open fires with chimneys that sucked
out warm sticky air, in order to cause smog and pollution in the cities
and towns, and by having draughty doors to let fresh air in, and wearing
woollens - sometimes the same set - all winter. And by using flexible
breathable lime rendering on their flexible wattle and lathe ..

Today we go far far deeper with rigid steel reinforced foundations, so
our houses don't move, and with open fires being a bit polluting, we
have efficient boilers and hot water heating, and sealed double or
triple glazed windows and sealed doors and pack the walls with insulation.

The net effect of that is what water IS inside, stays there and will
condense on the coldest part of the house - generally just behind the
insulation. So we install vapour barriers on the inside.

And then punch holes in the structure to achieve enough 'background
ventilation/air change' to let the sticky fug out in a controlled way.

We probably use far LESS energy to heat our houses than we used to
actually.

As I said, I am not arguing particularly for or against either method,
as both on their way work, and both are adapated to the resources available.

My complaint about modern houses is their soullessness. My response has
been to construct a house to modern standards using a mixture of
whatever worked properly and looked good and felt right. I've got single
glazed leaded light french doors in a steel encased frame. For example.
The look and feel is Lutgyens, the construction is post war steel..in
this case. I've got an oak and softwood frame stuffed to the hilt with
rockwool. I've got a slate floor with UF heating. And open fires. And
fully wired Broadband and TV...

The appearance is very traditional, and the sound of a door slamming
tells me I am in a timber house, BUT I don't have the cold, damp and
fungal smells associated with most of our local ones, and the house is
rigid enough not to need flexible plastering, and ventilated enough not
to need breathable walls.


I really do think that there is a sensible discussion to be engaged in
about what is the overall best way to build a house today, and I don't
thing the building trade has a monopoly on the right ideas any more than
either of US do, and certainly the governement is only interested in
metting self imposed target that take very little account of the quality
of life to be had inside the little hutches and kennels that they are
committed to supplying us with.

OTOH I am really for the *most* part a very firm supporter of current
building regualtions. Apart from the Part P and disabled ones which are
politically instigated, and not a reflection on 'best practice' as such.


The best of the old and the best of the new is my motto.








Anna



~~ Anna Kettle, Suffolk, England
|""""| ~ Lime plaster repairs
/ ^^ \ // Freehand modelling in lime: overmantels, pargeting etc
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