In defence of Cement

[Nemesis]

No as we have said, it's not modern hard Portland - much softer stuff.

http://www.belgraviastucco.com/page4.htm


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The idea of using stucco as an exterior finish on a large scale came about during the mid 18th Century. Large scale development by architects such as Nash had begun but the soft handmade bricks of the time gave a poor and dowdy finish. Seeing Italian stucco during the Grand Tour may have prompted the huge wave of interest in the material.

From 1750 to 1824 when Aspdin invented the first modern Portland Cement patent stucco was all the rage. It seems to have particularly interested the clergy and (shock horror) women! There were dozens of patents including one used briefly by Nash on the Royal Pavilion in Brighton containing sulphur and treacle, much loved by the local seagulls, less so by the Prince Regent.

Amazingly some of these materials are still found on buildings including the brown natural hydraulic cement of James Parker (1796) and the synthetic stone of the formidable Mrs Coade and the rarer Hamelins Cement (1817).

Not saying it eventually won't cause problems, and need repair, but if at the moment it ain't broke...


http://www.dartfordarchive.org.uk/technology/cement.shtml

http://www.thelimecentre.co.uk/Library/Best%20Mortar.pdf

 

[Essex]

Just to add my pennyworth.Two examples
1. My own house, 15C Essex timber frame, partly repaired in cement render 50 years ago, partly still with lime render. TThe cement render was removed and the timber frame required significant (and I mean money pit significant) repairs, the areas where there was lime render were fine. It took 50 years, and no one would have known if we had not removed the cement. The house could have suffered serious stuctural problems if it had been left.
2. Suffolk Housing Association, new housing, one set masonry cavity walls, partial cavity fill, the other hemp/lime with lime renders and limewash (very similar to daub and wattle with lime renders). All tested by BRE. The masonry houses, in theory, had better thermal perfomance (Uvalues etc), in practice, when measured, the hemp lime performed better thermally and, probably because of the hygroscopic properties of lime compared with cement, had fewer condensation issues.
For me, no contest lime over cement in traditional as well as modern buildings.

 

[Nemesis]

Marianne Suhr is currently detailing in Period Living mag the considerable repair work being carried out on her period home.

The new kitchen extension is being built with timber frame and hemcrete.

Worth investigating further as a building material I feel.

http://www.limetechnology.co.uk

http://www.backtoearth.co.uk

 

[Nemesis]

I feel in the cement and hisotory stakes I ought to mention Hennebique also.

One building using this technique is now the Malmaison Hotel on Newcastle Quayside - the former CWS warehouse.

His system was licenced and sub-operators could erect buildings using his technique.

François Hennebique Biography (1842–1921)



Civil engineer, born in Neuville-Saint-Vaast, France. He introduced the use of reinforced concrete for the building industry, commencing with flooring slabs in 1879, and progressing to a whole system which he patented in 1892. He built the first reinforced concrete bridge at Viggen in Switzerland in 1894, the first grain elevator at Roubaix in 1895, and the first multi-storey reinforced concrete framed building in Britain, Weaver's Mill at Swansea, in 1898.

More:

http://www.archives.gla.ac.uk/collects/catalog/ugd/251-300/ugd254-18.html

And of course Brooklands:

http://www.brooklands.org.uk/news/membank1.htm

http://uk.youtube.com/watch?v=CFE7vA2hjmo&feature=related

 

[Stephen]

When BSs came about in the 1920s it did cause the lime manufacturers major problems. My grandfather was a builder working in London at about this time and told me of slaking lime in a tub on site. How can on hope to meet a BS with such practices?

Even in the 1920s production of lime was rather haphazard as to standards. It is not the case now, but I believe that the BS only really applies to NHL again because of consistency in its manufacture. I may be wrong and I am sure others will correct me on this particular point.

The matter of stucco is complex. It is not formed from cement as we know it, but neither is it a pure lime render. I recall there being some papers written (internally) in RICS some years ago regarding stucco, its nature and maintenance and I will try to look them up.

 

[michael]

Take a look at:-

http://www3.westminster.gov.uk/spgs/publications/Stucco.pdf

It tells you almost everything you need to know about stucco and interestingly the different varieties that were used including those containing Portland cement. Also interesting is the use of cement in some of the repair mixes and the paints to be used in redecoration with the only specifications being colour and texture. No breathability here it would seem

 

[Flyfisher]

Thanks Stephen. I looked up the BS EN 459-1 standard and the current revision seems to be 2001. Other sources confirmed your view that the standard only relates to NHL, presumably defining the various NHL grades.

But I also found the now superseded 1995 standard . . .
DD ENV 459-1:1995
Building lime. Definitions, specifications and conformity criteria
Summary:Specifies quicklimes, hydrated limes and hydraulic limes.

. . . which suggests it covers other types of limes as well, although I'm not sufficiently curious to spend £52 on buying the full 28 page document. My anorak knows its limits

 

[Nemesis]

Also interesting is the use of cement in some of the repair mixes and the paints to be used in redecoration with the only specifications being colour and texture. No breathability here it would seem

Yes, that raises some intersting issues, which seem to have been recognised by the firm I posted the link to which specialises in stucco repair.

We are learning all the time about what is good and what is bad where historic buildings are concerned. The problem is that it takes time for the bad things to show.

 

[biffvernon]

Ah, there's no BS EN for soul.

 

[Nemesis]

Nope - and no BS Certs for past 'cement' mixes either, including past stuff called Portland which isn't the same as modern Portland, and where something may be pre-20th century and rare if I owned the building before doing anything to it in the way of major repair I would seek the expertise of someone like Simon Swann, have the exact mix analysed and think carefully about the most appropriate way to repair.

Some mixes can not now be reproduced, the exact methods of manufacture have been lost, and maybe treacle in the mix was not a great idea.

Some things which at one time were considered unable to be reproduced, such as Coadestone, it is now realised can be:

http://homepage.ntlworld.com/peter.fairweather/docs/Coade_Stone.htm
(Lots of Lincs examples at the page bottom Biff)

http://homepage.ntlworld.com/peter.fairweather/docs/index.htm

However, simply leaving it all to chance and a builder with a bag of blue circle isn't something I would wish to do.

 

[Gervase]

Some mixes can not now be reproduced, the exact methods of manufacture have been lost, and maybe treacle in the mix was not a great idea.

Still popular in India and Zanzibar, though, where lime plasters and renders are gauged with jaggery, which I suppose is pretty similar to treacle.

 

[Nemesis]

No seagulls maybe though?

 

[Nemesis]

I'll add this link here too, which is more about the book I posted about above:


http://periodproperty.co.uk/forum/viewtopic.php?t=8905


Brilliant stuff, should be required reading for anyone with a traditional building - especially those who think cement is a good thing for buildings intended to 'breathe'.

 

[Nemesis]

And a pic to show why it's a good idea to have the mortar softer than the building material:

That's a wall in a historic walled garden. The original soft brick/lime mortar is fine. At some point the wall was raised in height using cement mortar.

 

[Fizzer]

Just a little anecdotal evidence

I'm sitting next to a wall that had been rendered inside and out with cement in 1960.
When we removed the internal render 47 years later the walls were soaking, flaking and soft. We found our wooden lintels rotten (still haven't fixed them), the metal wiring trunking almost completely rusted away.
The external cement render shows signs of continuous repairs to cracking.

After a very musty smelling few weeks the brick has dried nicely and remains dry.

We'll definately be using lime to replace (once we've replaced the woodwork that has rotted)

 

[JMartin]

Absolutely Fizzer. Our internal walls were soaked through before we removed the cement render...a few weeks later nice and dry and no more musty smell.

The following pictures show what damage cement can cause. We wouldn't have known about this had we not had a leak in our downpipe.

http://naughtystep.wordpress.com/files/2007/10/dsc03016.jpg

http://naughtystep.wordpress.com/files/2007/10/dsc03019.jpg

http://naughtystep.wordpress.com/files/2007/10/dsc03015.jpg

For me there is no arguement. Whether people know it or not when they make their decision, cement is not the right material to put next to old masonry.

 

[Nemesis]

Have you managed to get most of it off now?

Oh - strange co-incidence time - the last issue of Country Life had an article on Coadestone and its remanufacture!

 

[JMartin]

Hi nemesis...I'm presuming you're asking me

We downed tools for the winter back in October and started on the interior jobs. Some more of it has been blown off in heavy winds and rain but aside from that it's still the same as it was.

The bit we did get off was the main cause of the problems though so we're nice and dry and don't smell like damp anymore. The downside to this is that I now have to iron my clothes again...no more damp making the creases fall out! :lol: Our loft insulation has helped no end aswell because now our house is warmer and any water in the air inside appears to be condesing on the toilet which I guess is the coldest part of the house since it's full of freezing mains water.

We've got another builder coming tomorrow to have a look. He was recommended to us by a restoration company. Hopefully he can do the job, leaving us the time to get sorted inside.

 

[Nemesis]

Sounding useful...

If you still have trouble finding anyone to do the work let us know and we may be able to suggest more contacts.

Yes, loft insulation makes a terrific difference, as indeed does some heating! (And ventilation of course.)


Which, with the cash saved, you can now afford...

 

[JMartin]

Thanks for the offer of help Nemesis. I'll bear that in mind.

Ventilation is no problem. There are more holes in this house than my sieve! The previous owner seems to have had a love of knocking fist sized holes in the masonry :roll:

I'll start a new post since I'm going a bit off topic...hang on.