"Andy Hall" wrote in message
...
On Fri, 12 Dec 2003 14:34:35 -0000, "IMM" wrote:


"Andy Hall" wrote in message
.. .

You have the mentality that all insulation fitters are cowboys.

That is not what I said either. I certainly think that the spray on
foam technique and its purveyors are questionnable because it is
marketed as a means of holding the roof material on rather than
repairing it properly.

That is very different to spay on cellulous.

If it hides the roof structure so that
it can't be inspected then that
is not a good idea.

Look at, which you need to look at:
http://www.warmcel.com/

Cellulous insulation is made from old newspapers. It is used as part of
breathing walls. As I said, which didn't sink in, it is used by most eco
home builders. It is not plastic based.

I'm all for doing proper energy management
and insulation, but the notion of putting ever
increasing amounts of insulation in lofts and
ignoring the walls is ridiculous; especially in
existing properties.

What strange logic!

Just simple physics

No strange logic.

The law of diminishing returns is important here.

Adding insulation to a wall cavity takes the U value from 1.5 to 0.5
which is highly significant. Adding insulation in a loft to take
the U value from 0.2 to 0.1, especially when the areas are considered
is of very little value in comparison,

A normal house is split into two halves a top half and a bottom half. In
then top half, insulating the loft to the best you get using cellulous
insulation is well worth it. Say 300mm. The Centre of Alternative
Technology say 350mm is the optimum, their book, The Whole
House Book covers this.

You can use alternative technology if you like.
I prefer to stick to with the economics and
proven technology.

How British! How 19th century! Read the book!! Don't guess as usual. All
is there. If our snotty uni man had read it first he wouldn't have a Heath
Robinson house with a screwed up heating system.

So in the top half of a house their is a highly significant ceiling
area that can be easily and cheaply insulated via the loft. My loft is
well
insulated and even recently in -2 temps, most of the time the TRVs were
fully off. In winter it is nice and snug in the upper rooms and in
summer
nice and cool. A win, win situation.

Likewise, and with only 150mm of insulation. The difference between
150mm and 300mm of insulation in terms of total energy saving isn't
significant.

It is. BTW, 300mm of cellulous insulation is equivalent to near 400mm of
mineral insulation.

It would almost cost more in petrol and environmental
impact to go to B&Q to buy the stuff.

Nonsense. Read "EcoHouse - A Design Guide". They say there is NO upper
level in insulation. As fuel gets more expensive, global warming takes
hold, with hotter summers (insulation keeps a house cool) and colder
winters, superinsulation is cost effective, and much sooner than you think.
And our resident estate agent will then understand the issues and sell
accordingly.

Looking at the whole house when assessing insulation levels is very
misleading. Loft insulation is easy and cheap and can be DIYed, unlike
say
cavity wall insulation. Do you understand it better now? I doubt it.

There's nothing to understand.

There is and you don't understand it.

You can bluster and alter the rules as
you go along as much as you like, but
it doesn't alter basic physics.

You were on about economics!!! Physics? No one is questioning that
insulation keeps heat in, in winter, and heat out in summer.



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