Species worth milling

[farmerjohn]

i'm not sure on that one, i'm too far north for thatched roof's to be used never worked on one, old buildings are mainly slate roofs with riven oak laths and iron nails that have rotted in the oak. 'nail sickness' as we call it.

[agg221]

Thatchers do use hazel spars, but the environment is very benign - longstraw thatch is grass, which lasts indefinitely. Some hall houses which were subsequently closed in have been found to have soot on the innermost layer of thatch, which dates it to 450yrs old or so.

 

Interesting to hear from you farmerjohn - I'm currently sorting out our house (on an ongoing basis) which is old enough to use very traditional materials. Reasonably familiar with lime now, but I'll remember who to ask!

 

Alec

[farmerjohn]

i deal with a few guys up here for lime products and they have developed a very intresting insulating lime render that i am going to try on my house and a grade 2 listed building we have to renovate as soon as the battle with the planning enforcemnt lot is sorted and my client can buy the place. I think that its just as important in modern times to insulate a house the way fuel prices are going and until now the only way to insulate a wall was using modern insulated plasterboard which is not sympathetic to a older property, now this other product is on the market i think it fits a really big gap in the market, is you are intrested drop me a line, i'm going to do a test run on my place make sure there are no problems with it.

if you want any detials on it let me know, or any other advice, i'm sure i'll need some reagrding timber soon,

cheers

[agg221]

Very interested to hear the results of your insulating lime render. My group are currently running the European project HIPIN (http://www.hipin.org) - one of the outputs from which should be a highly insulating lime-based render (we're working with a company called Vimark in Italy for this), so it would be good to get a comparison on price/performance.

 

At some point (when I've finished the extension so the children get bedrooms and we have a proper kitchen and bathroom) I will move on to removing the cement render from the timber frame, at which point I will need to render my own house - I have a personal interest in some of the projects we do!

 

Alec

[farmerjohn]

if you dont mind me asking, what do you mean by 'your group'?

i have tried the website and it did not seem to work, i would be intrested in reading up on it.

The company i get the insulating lime render from is called eden lime mortars.

I have insulated one side of the downstairs of my house with insulated 25mm plasterboard, I really want to insulate the other half with the lime render and then heat both sides up to the same temperature and get a thermal image of the outside to see what the heat loss is like through the walls for each product.

[agg221]

Hi John,

 

Sorry, web address should be Welcome - Hipin

 

Arb related stuff (inc milling and use of timber) is what I do out of the office. My day job is contract R&D where I run a group which works on a range of processes and advanced materials including high performance coatings and ceramics.

 

HIPIN is an EC funded collaborative project with partners across Europe developing high performance insulation systems. Our bit is stripping cost out of aerogels, Vimark are looking at using it in plasters, ARUP are working out how to quantify performance.

 

It's 1yr into a 3yr project so still a way to go but it's going we'll so far.

 

Alec

[Pete Bannister]

Farmerjohn, SPAB have published some interesting (although rather partial) research on thermal performance of trad buildings. SPAB: Energy Efficiency You might find it interesting.

The way chosen to retro-fit additional thermal insulation into traditional buildings is really important and requires more thought than is generally given to it! There's an obsession these days (which verges on the fetishistic) for thermal insulation and in some of our building stock it just doesn’t make sense.

[Pete Bannister]

Agg221, just looked at the Hipin site. Interesting.

 

What I said above wasn't a comment on Hipin (or any other materials) and certainly not intended as a criticism!

I can expand on my concerns ( based on experience in the UK) but this is perhaps not the forum for it.

[agg221]

Hi Pete,

 

Thanks for the SPAB links - an interesting piece of research. I've read the first paper, which I thought drew some generally interesting conclusions, although it didn't substantiate its conclusion with respect to the potential implications for damage from current practice - got a little hand-wavy at that point. I will read more later and see if it firms this up.

 

I'm in an interesting position. Professionally, I develop such things. Personally, I live in a 500yr old house which has been much abused. Sometimes I get to develop things which I think it would be good if they existed, and I would buy!

 

I suspect that I largely share your views - there's often a discrepancy between common sense and what the computer says. I think there are probably ways that the two can be reconciled in many cases, with due care, to reach a pragmatic compromise. In my limited (personal) experience the difficulty is that many decisions are taken either by people with limited understanding and a rulebook, or by people with very limited experience of advances in materials or arising understanding of their performance (think how many 'professionals' still re-point lime mortar brickwork with cement). This leads to a path of least resistance, which tends to be to adopt a common approach that works for the majority, and ignore (or fail to comprehend) that there may be implications for the minority.

 

An example - I've just been delayed six weeks in constructing my extension roof because nobody could agree on the correct way to install aerogel blanket installation. This isn't because they disagreed - they had just never heard of it and wouldn't make a decision. I ended up sending a sketch to the supplier, which they drew up as a CAD drawing and issued to Building Control with their own header in order to get it through.

 

I generally take the view that I wouldn't rip out a feature of historic value in the name of convenience or nominal improvement. However, where previous work has already removed something of value, and replaced it with something inappropriate that needs to come out anyway, I would be inclined to establish whether there was a sensible alternative to the original. For example, when the cement render over chicken wire comes off the outside of my walls, I may also be inclined to remove the internal plasterboard (between the studs) and the fibreglass between the two. At this point, I will have a section of bare frame. What goes back in may be more thermally efficient than the original, and more breathable than the current. This could potentially combine a lower thermal conductivity 'aggregate' than sharp sand in the plaster elements, and I will consider my options for the infill, with the aim of reducing thermal conductivity whilst increasing thermal mass for temperature stability.

 

I have probably just derailed this thread enough!

 

Alec

[difflock]

Agg21,

I like your train of thought and logic, vis-a-vis the mxing of the old methods with the new technology.

We just had a passenger overbridge/cyclepath installed at our local Victorian period railway Station, all curved stainless steel and LED lights.

 

Some have berated it as not in keeping with the Victorian vernacular.

I merely commented that by God iffen the Victorian engineers had of had stainless steel they would have used it wholesale, where appropriate.

 

Ditto when I installed a solid wood floor over underfloor heating back in 1996.

It was intended to stone slab this floor but back then the quotes were astronomic.

So I asked a couple of joiners why I should not "Gripfill" the cheaper solid oak wooden floor down.

 

No valid reasons being forthcoming I duly did. I me mysel that is.

 

The floor has never given any trouble to date.

 

PS

Also been interested in this aerogel product, as it sounds very promising.

 

Cheers

Marcus