[SimmondsMills]

I have passed your notes to David Olivier, our author for this response.

[SimmondsMills]

Thanks Andy!

[SimmondsMills]

Very much related:

Subsidies should end for many types of biomass, a new Chatham House report argues, because they are failing to help cut greenhouse gas emissions.

https://www.carbonbrief.org/biomass-subsidies-not-fit-for-purpose-chatham-house

[SimmondsMills]

2nd response: from Mark (and for the record I feel largely the same way as Mark so succinctly puts it, below)

“I'm a humanist first and environmentalist second.

People in airtight homes with filtered air and airtight woodburners may be comfortable and healthy, but the pollutants that drift into lower quality neighbouring houses appear to result in an equivalent to cancer causing passive smoking. …anyone fancy emphysema?

Whether it is fashion or stupidity, I personally can't justify or endorse activities that impair health and wellbeing or shorten the lives of people – even if it is to the benefit of the environment.

Mark

P.S. The global warming potential of biomass is often overlooked. As is the fact that Biomass is a Finite Resource. At a national/regional level sequestration is another factor that needs to be considered. Some good exploration/discussion of these issues:
https://aecb.net/publications/biomass-a-burning-issue
https://www.rspb.org.uk/Images/Bioenergy_a_burning_issue_1_tcm9-288702.pdf
https://www.foe.co.uk/sites/default/files/downloads/policy-position-bioenergy-79907.pdf
http://www.blog.foe-scotland.org.uk/index.php/2011/02/guest-blog-why-big-biomass-is-not-sustainable

[SimmondsMills]

It's now 2015, nearly 2016! I was just 'passing' this old post, thought I'd add a teaser for any eagle eyed ppl – that u should expect low vapour resistance spray foam applications coming onto the IWI market soon…

[SimmondsMills]

Here is the final response from AECB to DECC.
Feel free to send to colleagues who may interested.
Thanks to those who have contributed via email etc.
Thanks to AECB members David Olivier and Kate De Selincourt for their work pulling the response together.

[SimmondsMills]

Heinbloed

Let us know (if you know/find out) whether the german examples worked to these or similar standards.
I might ask the Passivhaus Institut if they have a view on this issue.

[SimmondsMills]

and at the risk of starting to give away AECB member guidance for free 🙂 some more on external wall insulation and fire:

“Currently EN ISO 6946.1996 advises that where the
thermal conductivity of a fixing or part of it is less
than 1 W/mK the effect of the fixing can be
disregarded in U-value calculations. However, for
Passivhaus and Gold Standard buildings, the heat
loss from mechanical fixings through the insulation
to the substructure should be accounted for, using
the χ-value of each fixing multiplied by the number
of fixings per unit area.
The system supplier may include the losses from
mechanical fixings in their quoted U-values. Indeed,
they are supposed to do so under current rules, as
these are repeating thermal bridges. But it is clear
that many suppliers do not do this. They quote Uvalues
which exclude the impact of any of the fixings.
Alternatively, the designer may wish to request the
system supplier to quote separately the U-value for
the insulated element alone and the further χ-value
due to all the point thermal bridges. This enables
him/her to investigate the benefit and the feasibility
of using fewer, or less conductive, mechanical fixings.
A smaller number of additional fixings may also be
needed to hold the render reinforcement mesh onto
the face of the insulation before rendering. This is
particularly true when applied to high-rise buildings
and in relation to fire issues. These fixings cannot be
countersunk with heads insulated over and may
constitute further thermal bridges that should be
accounted for. It is important to develop a clear and
detailed specification with the system supplier for
the approved installer to follow.
FIRE: Using EPS, Neopor or otherwise on high-rise
or multi-storey buildings, there may be a requirement
under the Building Regulations to limit the spread of
fire on external walls, as well as to reduce the risk of
disproportionate collapse in the event of a fire. BR
135 provides guidance on the requirements to
reduce these risks. This might require the
introduction of non-combustible fire breaks
horizontally at each floor level above second floor
and vertically at dividing walls between units.
Alternatively, if a proposed system without fire breaks
is tested in accordance with the relevant BS (BS 8414
Part 1 – masonry walls, or BS 8414 Part 2 – steel frame
walls) and is assessed in accordance with BR 135,
then it is deemed to comply with the requirements.
On mechanical fixing, BR 135 states: ‘Use no fewer
than one stainless steel fixing – in addition to those of
plastics – per square metre of insulation. The fixings
should be sized and fitted to resist the increased
duty that may be required under fire conditions’.
Generally, therefore, for an EPS insulated render
system on a multi-storey building, the insulation
boards would be adhesively bonded and mechanically
fixed, usually referred to as initial fixings. In
addition, after the render and reinforcement have
been applied over the EPS, further mechanical
fixings would be inserted in stainless steel at a
minimum rate of 1 no. fixing per square metre of
wall area. Typical stainless fasteners would have a
cross-sectional area of ca. 13 mm2.
The number of initial fixings is dependent on the wind
suction forces acting on the building and the dead
weight of the system. Where insulation is being applied
in two layers, there is the added complication of the
fact that at each stage of the installation, the applied
insulation boards should be secure and able to
withstand the wind suction forces acting on them.
Therefore, for the scenario in considered in Section 3
of this guidance document both layers of insulation
boards would require ‘initial’ fixing with a similar
number of ‘initial’ fixings.
Using 4-5 initial fixings per insulation board would be
considered typical. The first layer of insulation boards need
not be fixed using the recessed head type fixings,
since these heads will be trapped behind the second
layer of insulation. The second layer can either be
recessed head fixings, which tend to have a metal pin
running down the centre and are therefore more heatconductive,
or plastic fixings, with reinforced plastic
pins running down the core, having a lower χ-value
than the recessed head types.
Where mineral fibre fire breaks are used, these are
usually fully adhesively bonded and mechanically
fixed, with additional fixings through the render
reinforcement mesh so that, in the event of the EPS
insulation melting away in a fire, the reinforced
render system, which will be very heavy on a
multistorey building, is still mechanically secured to
the load-bearing substrate.
The analysis below is based on horizontal fire
breaks at each floor level.”

[SimmondsMills]

Heinblod
another example wrt fire risk for polystyrene external wall insulation

“A fire barrier may be required at intermediate floor level in external
wall insulation systems for buildings over 2 storeys, where the insulation
system employs insulation that is not of limited combustibility. With
regard to fire breaks, refer to BR 135 ‘Fire performance of external
thermal insulation for walls of multi-storey buildings’ and BS 8414
Parts 1 and 2.”

The guidance has detailed illustrations of applying these principles

[SimmondsMills]

Heinblod
AECB Carbonlite guidance (for AECB members only) covers some of the issues you raise – or at least touches on them. It goes on to detail ways of dealing with or mitigating these risks. for example on damage to insulation:

“Adequate care must be taken to reduce the risk of insulation
damage from vermin. We now know from many authorities that this
may be a more serious problem than insulation manufacturers have
advised in the past. Insulation is a fragile material and must be
carefully protected from the risk of attack below ground. Such
materials as sheet metal, concrete paving slabs, concrete and
similar have been used.”

[SimmondsMills]

Hi Heinbloed
I notice that you have been posting an awful lot of comments and links etc.
Some of the issues that these links raise are valid concerns that we all need to be assessing.
Some of your comments likewise are useful, however some comments seem a bit wild (as in not well substantiated).

What I – and others – would find much more useful – given everyone's general lack of time to take in and digest all of your posts and links – and would indeed welcome if you were able to – would be for you to summarise succinctly in one post all the concerns you have picked up over the last few months. e.g.,
1. fire risks of EPS EWI
2. degradation of insulation materials under concrete raft foundations
3. etc

Otherwise I fear that the sheer volume and spread of your posts will defeat our ability to respond / make the best of.

I am looking forward to it!

BW

Andy Simmonds

[SimmondsMills]

we are going to move this thread as is duplicating the dicsussion – bear with us

[SimmondsMills]

It would be great to get a low cost option sorted. Hygrotrac is an opportunity to get a top end system available to members at reduced costs. I am using one on an IWI project (not my house) and it has the following advantages for us:

I dont have to drive to the site. saves time = cost.
I can analyse data via xcel download or via the online interface (graph based) – very good this bit, and print out reports.
batteries are meant to last 10 years or so. we have built the wireless sensors in. One has failed due to I think liquid water getting in to the area of that sensor from an unpointed brick subcill that NEEDS SORTING!! (the sensor is directly below). We have 11 sensors in place, 2 ambient, 8 in the walls and 1 in a ceiling.

Cost – I organised sponsorship to cover the equipment and online costs leaving us to cover the time involved. Others are getting the client to pay for it.

on self build/owner occupier retrofits a cheaper solution would be useful.

OUr webmaster is looking into the potential of the low cost raspberry computer…but we all need to get stuck in to identify the best affordable solution – then AECB could see if we can get a deal for that as well.

the way we used the sensors is fully described in my IWI risk presentation uploaded in the aecb conference presentation section on this website. here https://aecb.net/PDFs/conference12/Andy_Simmonds_Wall%20insultation.pdf

[SimmondsMills]

Well. This is where we are now discussing mad ideas to save the world (well to save the UK first): https://aecb.net/forum/index.php/topic,3540.new.html#new

[SimmondsMills]

Thanks. trying to raise the last bit of cash to get the online server and mobile internet conection set up!!! bit close to the wind….any offers appreciated…

[Author]

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