Jump to content
Strawberry Orange Banana Lime Leaf Slate Sky Blueberry Grape Watermelon Chocolate Marble
Strawberry Orange Banana Lime Leaf Slate Sky Blueberry Grape Watermelon Chocolate Marble

Featured Posts

Nothing to do with canals but still heritage

 

Rebuilding a cemetery wall - the wall is of no intrinsic value but because the building is listed so is the wall. The building is circa 200 years old, the wall is of indeterminate age, could be less than 50, but it was there at the time of listing. 

 

Conservation officer is insisting on lime mortar for the rebuild, but the problem is that mortar in the wall consists mainly of power station ash - CO claims it must have lime in it otherwise it wouldn't bind, I'm not so sure. 

 

Does anyone know? When did lime stop being a common constituent of mortar, when did cement start to be a constituent? Is there mortar that would have had neither? 

 

I don't think we can readily replicate the original mortar anyway - no local power station these days

 

 

 

Edited by magpie patrick

Share this post


Link to post
Share on other sites

Our local builder (Taskers of Southport) was still producing their own  lime mortar in the late 60's.  They had a slaking pit,  and a mortar mill.   Mortar came in white,  which contained washed local sands, and was cream coloured, or grey which contained ash, and was dark grey. White was always available.  Grey usually needed to be ordered.  Cannot remember the source of the ash.

 

  I think the chemistry of mortar means you have to have some burnt limestone/chalk/ other source of Ca oxide or hydroxide in the mix, so that CO2 is absorbed from the air and carbonates (???)  form to hold the aggregate (sand etc.) in place.  ISTRR that burnt cockleshells or similar will work in mortar.

 

N

 

Share this post


Link to post
Share on other sites

Plenty of Limbux hydrated lime around, Samuel Longsons in Chapel-en-le-Frith shift loads. But a mill for sand grinding is another matter. 

 

Don't the likes of Tarmac do ready mixed lime mortar?

The original lightweight blocks were made from fly ash, now ground sand and aluminium powder is used.

Share this post


Link to post
Share on other sites

Problem is related to this resulting from enforcement because work had started.... it's two fold

 

The main building is listed - the guidance from HE is that any items of interest in the curtilage are also listed, and the guidance even states that the debate is often not whether an item is within the curtilage, but whether it of interest. I have tried to argue the wall is not of interest for a variety of reasons, it isn't contemporary with the building, it isn't architecturally related, it isn't even the boundary! I am a little irritated at the CO won't even admit she has this discretion and has decided not to use it. 

 

Second the mortar being used is not lime mortar (although by the CO's own logic it must be because mortar won't work without lime!) - however what she is asking for isn't what the wall has been built with. I'm trying to see whether there is a good argument that non-lime mortar is as authentic as lime mortar, because if it's not the trustees will have to take the wall down again and rebuild it, and they're a bunch of voluneers who have brought the cemetery back from ruin with their own sweat and blood - they're not made of money. 

Share this post


Link to post
Share on other sites

CO s usually have discretion but they also have Power which is the main problem in this case by the sound of things. Lime mortar is not a problem to obtain or use and stone buildings are usually made and pointed with it as it’s more flexible than Portland cement mortar. In most areas there is usually what is called building or soft sand which is the stuff to use not double washed or sharp sand.

Share this post


Link to post
Share on other sites

The problem is that lime mortar is poorly understood, and by no means conforms to a standard. Rennie's notebooks are full of details about the limes he came across around the country. German and French engineers began looking at detailed compositions late in the 18th century, with English-language publications becoming more widespread in the 1830s. Just show her this graph and ask which particular type of lime mortar she requires.

limespec.jpg

  • Greenie 1
  • Happy 2

Share this post


Link to post
Share on other sites

I suppose it might come down to how much you need or want to play the CO’s game. Is there a (friendly to you) lime wall building specialist you could bring in for a meeting?

Share this post


Link to post
Share on other sites

I have been reading up on lime mortars as we have a lock cottage and the outbuildings needed repointing in places. I used premixed mortars from Limestuff Ltd. This worked OK, was very easy to use etc. I had no need to match the original mortar as the building have been painted, but I found several suppliers offer a mortar analysis service perhaps these can offer advice? Note other suppliers are available and I have not used this particular one:- https://www.lime-mortars.co.uk/lime-mortar/guides/mortar-matching

Share this post


Link to post
Share on other sites

Don't be afraid of lime mortar. Keep the CO sweet, and buy a ready-mixed tub of it or three. It might be a smidgen more expensive than cement-based, but in the grand scheme of things its the repointing work that's the expensive part. And it will look more beautiful and help to preserve the bricks for the future better than cement-based would. 

 

I am not a CO.

Share this post


Link to post
Share on other sites
On 02/07/2020 at 18:55, magpie patrick said:

Problem is related to this resulting from enforcement because work had started.... it's two fold

 

The main building is listed - the guidance from HE is that any items of interest in the curtilage are also listed, and the guidance even states that the debate is often not whether an item is within the curtilage, but whether it of interest. I have tried to argue the wall is not of interest for a variety of reasons, it isn't contemporary with the building, it isn't architecturally related, it isn't even the boundary! I am a little irritated at the CO won't even admit she has this discretion and has decided not to use it. 

 

Second the mortar being used is not lime mortar (although by the CO's own logic it must be because mortar won't work without lime!) - however what she is asking for isn't what the wall has been built with. I'm trying to see whether there is a good argument that non-lime mortar is as authentic as lime mortar, because if it's not the trustees will have to take the wall down again and rebuild it, and they're a bunch of voluneers who have brought the cemetery back from ruin with their own sweat and blood - they're not made of money. 

Is there not a compromise available where the sections of wall the volunteers have already rebuilt are allowed to remain, but lime mortar is used for the rest of the work?

Share this post


Link to post
Share on other sites
On 02/07/2020 at 17:03, magpie patrick said:

Nothing to do with canals but still heritage

 

Rebuilding a cemetery wall - the wall is of no intrinsic value but because the building is listed so is the wall. The building is circa 200 years old, the wall is of indeterminate age, could be less than 50, but it was there at the time of listing. 

 

Conservation officer is insisting on lime mortar for the rebuild, but the problem is that mortar in the wall consists mainly of power station ash - CO claims it must have lime in it otherwise it wouldn't bind, I'm not so sure. 

 

Does anyone know? When did lime stop being a common constituent of mortar, when did cement start to be a constituent? Is there mortar that would have had neither? 

 

I don't think we can readily replicate the original mortar anyway - no local power station these days

 

 

 

Patrick I suggest that you join the Brick of the Day Facebook page and ask your questions on it. You will then have the benefit of the large knowledge of people who contribute including experts on building renovation. Its a very well moderated page so that you get no trolls. https://www.facebook.com/groups/1548100792073477/

Share this post


Link to post
Share on other sites
55 minutes ago, David Mack said:

Is there not a compromise available where the sections of wall the volunteers have already rebuilt are allowed to remain, but lime mortar is used for the rest of the work?

Thanks David - Having seen the wall on Saturday, first time in three months, that's what I think I'll aim for. I was a bit worried that they might have finished building it during lockdown! 

25 minutes ago, Richard T said:

Patrick I suggest that you join the Brick of the Day Facebook page and ask your questions on it. You will then have the benefit of the large knowledge of people who contribute including experts on building renovation. Its a very well moderated page so that you get no trolls. https://www.facebook.com/groups/1548100792073477/

Joined - thank you!

 

Share this post


Link to post
Share on other sites

If you look at old newspapers the word cement occurs quite early on and the word Roman Cement is also another term commonly used. As to the burning of limestone to create lime, this process changed  with kiln development and the changes that led to the establishment of "cement" works- many railway served. It must be a factor of these changes as to why the term cement came into common usage. Such changes were also driven by the need for cement in large scale construction processes.

 

As to the basic chemical composition of well that is variable-

 

Lime or calcium oxide, CaO: from limestone, chalk, shells, shale or calcareous rock. Silica, SiO2: from sand, old bottles, clay or argillaceous rock. Alumina, Al2O3: from bauxite, recycled aluminum, clay. Iron, Fe2O3: from from clay, iron ore, scrap iron and fly ash.

 

It makes sense for the wall in question to have analysis of some kind. Yet for old walls, the most likely source of lime must be considered and if it was conveyed by canal boat from a place that produced the type of limestone needed for the job.

Share this post


Link to post
Share on other sites

Here's some info about the types of mortar that were being used when the 11th edition (1910-11) of the "Encyclopaedia Brittannica" was written. It appears that, for lime:sand mortar, the type of lime used was so-called "eminently hydraulic lime", which could produce strong mortars that would set properly. Examples are given of old, evidently non-hydraulic, lime mortars that had been revealed during demolition, which had not set after a couple of hundred years. If eminently hydralic lime was not available, it was necessary to include a proportion of portland cement in the mix to obtain mortars that would set.

 

The attached extract from the 1976 edition of the government's Property Serices Agency [PSA] leaflet No 16 indicates that, by 45 years ago, eminently hydraulic limes had become virtually unobtainable, and I don't suppose the supply situation has improved today.  Unless supplies of the  eminently hydraulic lime that used to make satisfactory lime:sand mortar a hundred or more years ago are in fact still available,  a cement: lime: sand mixture would have to be used nowadays to produce a mortar with a mechanical strength comparable with the original lime mortar: a mortar consisting only of modern lime and sand is unlikely to set properly.  I normally use a 1:1:6 cement:lime:sand mix for bricklaying. Mortar without lime is too harsh, as well as being too strong. The inclusion of lime yields a mortar that is almost white when dry,  very different in appearance from the grey colour of 1:3 cement: sand mortar used for pointing.

 

I should point out that I am not a professional builder, but when I needed to do some diy brickwork in my first house many years ago, and having no money to pay a builder,  I read up on the subject in text books written for the trade, as well as the excellent seres of leaflets on good building practice published by the PSA and the Building Research Establishment. They used to be available from HMSO at very reasonable prices before everything got privatised. 

 

Ps the attachments don't seem to have attached. I will try again tomorrow.

Edited by Ronaldo47
Typo

Share this post


Link to post
Share on other sites

Have a look at the "listed properties owner club" website. Loads of good info on there plus links to suppliers

Share this post


Link to post
Share on other sites

I have recently bought lime to complete some bricklaying on our lock keepers house.  Hanson supply lime of different grades  NHL 2, 3.5 and 5. There is plenty of good information on their website, in particular look at the technical data sheets for each grade of lime.

 

I have used NHL 3.5 (like Moderately Hydraulic if I understand the gradings correctly)

https://www.hanson-packedproducts.co.uk/en/products/conservation-mortars 

 

I have used this only for a small amount of pointing so far, but found it works fine.  The lime is relatively expensive, I paid approx £20 per bag but this included courier delivery.

 

Share this post


Link to post
Share on other sites

Thanks for the info, nice to know that hydraulic lime is indeed still available. I guess the high price reflects the scarcity of the remaining natural deposits. 

 

Second attempt at posting attachments.

 

Still no joy, attached 3 files in GIF format at under 600k each, no error messages, but nothing showing up on my phone screen. 

Edited by Ronaldo47
Post script re attachments

Share this post


Link to post
Share on other sites
5 hours ago, Tonka said:

Have a look at the "listed properties owner club" website. Loads of good info on there plus links to suppliers

Joined!

 

2 hours ago, Ronaldo47 said:

Thanks for the info, nice to know that hydraulic lime is indeed still available. I guess the high price reflects the scarcity of the remaining natural deposits. 

 

Second attempt at posting attachments.

 

Still no joy, attached 3 files in GIF format at under 600k each, no error messages, but nothing showing up on my phone screen. 

Not to worry, your original post was very useful thanks

Share this post


Link to post
Share on other sites

I didn't bother scanning the last part of the EB article as it is only two lines that complete the sentence about the USA. However, on reviewing it, I notice that the article does end with four lines of references. As these might be of interest to those involved in conservation who might need further information on Victorian building practices, here is the final passage of the article:

 

"(The principal seat of manufacture is Coplay, Pa, where the first ) American Portland cement was manufactured in 1874 by Mr. David O. Saylor. 

   The chief works of reference on this subject are G. R. Burnell, Limes, Cements, Mortars; Rivington, Notes on Building Construction; F. W. Taylor and S. E. Thompson, A Treatise on Concrete, Plain and Reinforced. "

 

When things get back to normal, it should be possible for your public library to get copies of these books from the British Library. I have borrowed copies of Victorian books in this way in the past, although a fee is normally payable these days.

 

Edited by Ronaldo47
Typo

Share this post


Link to post
Share on other sites

You can download books, such as 1780 Higgins, Experiments and observations made with … cements, and though the best ones are in French or German, there are several translations, such as the standard work by Vicat.

 

The photo shows one of my favourite L&LC limekilns, just to the east of Silsden. Coal and Limestone were brought by canal, which crosses the stream by the aqueduct on the left. After burning, the lime was raked out of the kiln and slaked using water from the stream. There are several similar limekilns surviving along the canal.

P4101962.jpg

Share this post


Link to post
Share on other sites

I suspect that lime and burning lime in kilns was done at a time before such detailed research in to properties had yet to be done. Whilst it is clear that certain limes had specific properties, the distribution of kilns along the waterway, or turnpike, was through the distribution of limestone by canal boat or waggon. Local sources were a factor in the location of such kilns.

 

Coming back to the original post the use of lime as cement was probably dictated by the locality. But then with the growth of railways transport of cement became more available and builders could choose the source of material. Limestone also came to have uses in greater quantities for other industries such as iron smelting, alkali and other chemical manufacture.     

Edited by Heartland

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.