new ceiling: clayboard vs plasterboard vs reeds

[Maris]

Hello,
I'm looking for an alternative to gypsum plasterboard for our soon-to-be-built new ceilings. Since the house is being repaired with earth and lime mortars I'd like to avoid using any non-breatahble plasterboards internally. The alternatives all seem a tad expensive. Like, clay board being 10 times the cost of plasterboard, and similar for new lath and plaster. Its a bit shocking really. Are there any other alternatives? Reed matting seems reasonably priced, but how easy is it to plaster? And will it be acceptable to to our (fairly tolerant) building control officer?

any thoughts gratefully received.

cheers

Maris

 

[Gervase]

Reed matting is not quite as simple to plaster over as lath, but with practice it does give a good finish.

You'll need plenty of staples to fix the matting to your timbers - I use one every fourth reed - and make sure when you fix the stuff up that it's pulled taut. This is not only to give you a nice flat surface to plaster; it also ensures that there's enough space between the reeds for the plaster to form nibs. Put it up slack and you'll have the devil of a job forcing well-haired plaster between the reeds (and you should use plenty of hair cut at least one and a half inches long).

Just before you start plastering when the mat is up, give the whole thing a brisk brushing with a coarse-bristled churn brush or scrubbing brush to remove any loose leaves or 'flag', as these will stop the plaster nibbing and getting a good key.

As the reeds are shiny they aren't as good as laths when it comes to getting plaster to stick, so when you're laying on, move your trowel from virgin reed back to the plastered bit, ending your stroke on a piece you've already plastered. Do it the other way and the plaster will drop stright to the floor!

Keep the mix a bit stiffer than you would normally, and remember to push hard as you apply it - the gaps are closer together than lath, and it does take a bit of shoving to get the plaster through.

That said, once your scratch coat is on and scored, the rest is just like any other plastering. You'll be amazed at how strong and dense a reed-based ceiling can be.

 

[GK]

... You'll need plenty of staples to fix the matting to your timbers - I use one every fourth reed ...

Yeah, I saw someone on the telly doing it like that. Very brave, I thought, relying on all that weight supported by a few staples. I chickened out and put a riven lath over the whole lot on every joist. The extra advantage is that you can see where the joists are because the lime has to be a bit thicker to cover it.

Well, when people remark about the lumpy ceiling, I tell them it's an advantage.

 

[Gervase]

Very brave, I thought, relying on all that weight supported by a few staples.

I've not heard of one coming down yet. Nearly all our ceilings are reed-based, and they've endured no end of tap-dancing cats and other horrors without mishap.

In a perfect world I'd love to have used riven lath, but it's just so bloody expensive. It is easier to plaster over, as I found with the one surviving lath ceiling in our place. Ah well, one can dream...

 

[Craig]

Gervase - wasnt that person on the TV you?

 

[Gervase]

Er, it may well have been. Unless some other lunatic's agreed to be filmed plastering a reed mat ceiling. I gather that on ITV3 there's little else!

 

[NT]

Hello,
I'm looking for an alternative to gypsum plasterboard for our soon-to-be-built new ceilings. Since the house is being repaired with earth and lime mortars I'd like to avoid using any non-breatahble plasterboards internally. The alternatives all seem a tad expensive. Like, clay board being 10 times the cost of plasterboard, and similar for new lath and plaster. Its a bit shocking really. Are there any other alternatives? Reed matting seems reasonably priced, but how easy is it to plaster? And will it be acceptable to to our (fairly tolerant) building control officer?

any thoughts gratefully received.

cheers

Maris

Gypsum is breathable.

I've always wondered what the advantage of clayboard is, but have yet to hear of any, other than its greater mass and thus better sound deadening.


NT

 

[biffvernon]

I've always wondered what the advantage of clayboard is, but have yet to hear of any, other than its greater mass and thus better sound deadening.

Smaller eco-footprint.

 

[thiambal]

Gervase - did not know we had a TV star in the midst - I thoroughly enjoyed the spectacle of seeing you plaster reed matting - I have to admit to being skeptical at the time - glad to hear that is has been a success!! Well done old chap!

Trying to remember which programme it was now - was it a Beeney Baby special?

 

[Maris]

Thanks guys,
all very useful stuff. I assume reed matting can be used in partition walls as well as ceilings?
I'm sure I found a thread on this site somewhere that states that gypsum plasterboard is not breathable. I'll go and see if I can find it again..
If it is though, can I use a lime plaster over it?
My husband's gone off to look for a series we taped a few episodes of called 'Restored to Glory'- he recalls someone using reeds instead of laths in that.

 

[Maris]

I've just looked at the 'Information' section on this website. It has, at the very top, a link to 'Restored to Glory', which shows somebody I assume to be Gervase putting up and plastering a reed ceiling! if only I'd looked through the site more thouroughly before posting... anyway, the ceiling looks great.

cheers

Maris.

 

[NT]

Gypsum soaks up water like a sponge, so its breathable, whatever might be said at times.


NT

 

[NT]

I've always wondered what the advantage of clayboard is, but have yet to hear of any, other than its greater mass and thus better sound deadening.

Smaller eco-footprint.

cheers, hadnt thought of that one. But I cant help but have 2 reservations. The main energy use is not usually manufacturing process but the other activities that are needed to run a business. With a very small scale product like clayboard, the total eenrgy used per board is liable to be much higher, simply because of the efficiencies of scale with plasterboard or lime.

Then theres transport. 1" thick clay mud boards are a whole lot heavier and larger than 9 or 12mm PB, and that means per board: more fuel use, more vehciles on the road, more labour, just less econess all round.

Perhaos the ideal thing would be a thin modified mud board, eg fibre reinforced clay 12mm thick.


NT

 

[biffvernon]

I think this clayboard manufactured at a distance is a temporary, transitional material. The material first has to become accepted as a 'good thing'. Then we must develop the ways of making it on site with immediately local material. Zero transport, close to zero embodied energy, an eco-footprint no bigger than the water feature that is left in the new build's back garden.

I was intrigued to learn on a recent visit to Cheltenham, that most of those wonderful Regency terraces were built with brick made virtually on site. In the early 19th century there were many small brick works and the bricks were usually used within a few hundred yards of manufacture.

 

[Nemesis]

Mr Cubitt, Isle of Wight, Osborne House, Queen Vic... and Prince Albert.

http://www.english-heritage.org.uk/server/show/ConProperty.205

Although rendered, the building is of brick and these were specially made on site. Brickworks presumably were not numerous of the island at that time.

There's a mention here of early brick making on site:

http://www.periodproperty.co.uk/article033.htm

Many collieries had brickworks, using the clay found in mineworking seams, and colliery terraces were fequently made from these bricks.

 

[NT]

I think this clayboard manufactured at a distance is a temporary, transitional material. The material first has to become accepted as a 'good thing'. Then we must develop the ways of making it on site with immediately local material. Zero transport, close to zero embodied energy, an eco-footprint no bigger than the water feature that is left in the new build's back garden.

I was intrigued to learn on a recent visit to Cheltenham, that most of those wonderful Regency terraces were built with brick made virtually on site. In the early 19th century there were many small brick works and the bricks were usually used within a few hundred yards of manufacture.

Here we go back the the principles of the industrial revolution. If you manufacture clayboard on site, it is done at low speed and high labour input compared to complex efficient streamlined factory production lines. Producing board on site is thus the opposite of green, it uses far more labour and time, and labour equals resource consumption.

The industrial revolution transformed peoples lives by moving most production from the home to the factory. It is because of this we can afford to even consider green issues. It is because of this we can use computers, research, use the internet, make product designs much more efficient and so on.


That leaves one question: transport. Highly efficient mass production inevitably means transport, and that uses a fair bit of energy and other resources. Still less than onsite production though. What we need for the future is a minimum energy transport system. We need goods that can be transported overnight by unmanned vehicles at energy-optimum speeds on roadways separate to human transport. Railways are close to this, but perhaps in future a lighter automated system will allow delivery closer to the end user, smaller cargoes while maintaining efficiency, and better cost and energy efficiency.


NT lands back on earth.

 

[BMcD]

NT wrote:

The industrial revolution transformed peoples lives by moving most production from the home to the factory. It is because of this we can afford to even consider green issues.

Surely it because of the industrial revolution that we're in this mess in the first place.
And as for transport, you seem to have only considered the transport of the finished product from factory to end user. What about the transport of raw materials to the factory and the workers to the factory? what about the construction of the factories and all the infrastrusture that goes with it?

 

[biffvernon]

I'm not sure, NT, why you regard a labour intensive process as equal to high resource consumption. Our six billion souls times three score and ten years is at least a renewable resource. But we have to find a way of making it sustainable. And that means largely independent of fossil fuels.

The industrial revolution has, as BMcD points out, been something of a double edged sword. Along with the undoubted benefits it has also brought in its wake, previously unheard of levels of pestilence and warfare, and now the threat of global climate change which has the potential for wiping humanity from the face of the planet. (See Richard Duncan and the Olduvai Theory.)

We now need to move to a post-industrial system in which we preserve our cultural heritage and produce our shelter, food and entertainment in ways that repair the planet rather than add further damage. The local production of building materials with a low embodied energy and which causes little pollution in manufacture, use and re-use, should be of central concern to those of us who care for our old buildings and want to leave a further legacy of new buildings to be cherished in future centuries.

I'd go for the clayboard.

 

[middi]

Biff, I totally share you views on the green/conservation approach as being the way forward in order to prolong the life of the planet and humanity as we know it.

I also agree with BMcD with the fact that the industrial revolution signalled the point of no return in preserving the "status quo" with its deterimental side effects as far as the planet is concerned.

It is also my belief that the only way to slow down and reverse the rot we will have to rely on, as you said, " double edged sword" of advanced technologies.

All we have done is provided ourselves with the monumental task of a clean up act which has to be instigated at human culture and behaviour pattern level and have faith that we will not make the holes in the sieve any bigger.

We all know that we cannot "undo" the nuclear bomb, we have to manage it to our benefit.

 

[NT]

> Surely it because of the industrial revolution that we're in this mess in the first place.

Indeed, more or less. We're lucky, without the industrial revolution we'd be in a far worse mess instead. Instead of pondering these high class problems over tea and cookies in our centrally heated houses, 50% of us would be dead, 50% of us would work out in the fields, we'd have had relatively little education, no internet, and due to minimal ability to afford scientific research, the majority of the innovations that have happend since the time of the industrial revolution would not exist. Nearly all of us would be living in conditions we now call poverty, with only half todays life expectancy. Global warming would be the least of our worries.

When I say more or less, there is I suppose the question of whether the industrial revolution could have occurred without the mass use of fossil fuels. Concentrating reflector arrays might possibly have powered many steam engines.


> And as for transport, you seem to have only considered the transport of the finished product from factory to end user.

Why do you think that?


> What about the transport of raw materials to the factory

Almost always in bulk, and we have suitable infrastructure for that. I cant see any way it could get a lot better. Can you? Actually I can, but indirectly. As product design evolves we see ever less material use for a given product function. This can be improved further by cutting back on the throwaway mentality... for which I have another idea.


> and the workers to the factory?

I've got a separate scheme for that. Let people use motorised gocarts for short journeys, putting them in separate lanes to cars with physical barriers for safety. Gocarts do upto 30mph which is fine for short journeys across town, use a fraction of the fuel, take up a fraction of the roadspace (solving the congestion problem and dramatically increasing the amount of people present roads can move), present a fraction of the danger, are a fraction the cost to build, need far less regulatory framework, and are big enough to carry people, shopping and small deliveries.


> what about the construction of the factories and all the infrastrusture that goes with it?

What about it?


NT