Green Building Forum - Is it acceptable to use Ordinary Portland Cement [OPC]? Sat, 18 Apr 2026 14:22:05 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21857#Comment_21857 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21857#Comment_21857 Mon, 26 May 2008 18:35:05 +0100 Rachel Sorry, I did mean 40% of the worlds C02 emmissions... I can see that their figures CAN be realistic, especially with the amount of cement that China, USA, and now developing countries are pumping out.]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21867#Comment_21867 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21867#Comment_21867 Mon, 26 May 2008 19:33:47 +0100 paul.dixon27 Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21870#Comment_21870 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21870#Comment_21870 Mon, 26 May 2008 20:05:18 +0100 jon
The concentration of the articles cited on initial capital embodied carbon appears to me to be, at best, misguided.]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21879#Comment_21879 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21879#Comment_21879 Mon, 26 May 2008 21:01:39 +0100 biffvernon Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21886#Comment_21886 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21886#Comment_21886 Mon, 26 May 2008 22:03:46 +0100 Mike George
How much lime comes from abroad, and how much will this increase if [more local] cement production were to be reduced?]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21888#Comment_21888 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21888#Comment_21888 Mon, 26 May 2008 22:39:34 +0100 biffvernon Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21889#Comment_21889 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21889#Comment_21889 Mon, 26 May 2008 22:41:18 +0100 Mike George Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21897#Comment_21897 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21897#Comment_21897 Tue, 27 May 2008 07:17:42 +0100 jon Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21898#Comment_21898 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21898#Comment_21898 Tue, 27 May 2008 07:38:44 +0100 biffvernon
Jon, you need to look a bit harder!]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21902#Comment_21902 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21902#Comment_21902 Tue, 27 May 2008 07:50:44 +0100 jon
I used the ethical arguments published below for the evaluations:

http://www.istructe.org/thestructuralengineer/HC/Abstract.asp?PID=7682

I think it is up to the proponents of lime to prove their case. I have not seen this demonstrated but, if it could be demonstrated, I would be very interested.]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21904#Comment_21904 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21904#Comment_21904 Tue, 27 May 2008 08:08:49 +0100 Mike George Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21906#Comment_21906 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21906#Comment_21906 Tue, 27 May 2008 08:13:48 +0100 Mike George
Price is often the bottom line for most customers, with green considerations coming second I'm afraid. For that to change lime needs to come down in price, and if there were increased demand, maybe it would - who knows

Getting back to Embodied Energy, given the information gleaned from the papers listed so far here, it is not clear how much energy is used in the production of lime, only that it 'can be on a par with cement'

I doubt that Singleton Birch would be forthcoming with that information either, having tried and failed in the past to find out this kind of data for insulation material. If it were good they would surely advertise the fact.

It also seems that Lime can incur significantly more energy use in transportation to merchant/site than OPC as a lot of it comes from abroad.

I just wish when statistics are presented they would give the whole picture rather than just the part that suits the presenters own ends. I suppose that is why they were invented]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21914#Comment_21914 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21914#Comment_21914 Tue, 27 May 2008 08:45:22 +0100 jon
The reason that lime proves to be almost irrelevant is that the embodied content of mortar, when carbon discounting is set to zero, is so small: Hence lime only becomes ethically justifiable if it increases the durability of the structure under consideration.

Edit: I'll try and get Kathy to change it's status if there's enough interest]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21930#Comment_21930 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21930#Comment_21930 Tue, 27 May 2008 10:36:23 +0100 Chris Wardle Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21938#Comment_21938 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=21938#Comment_21938 Tue, 27 May 2008 11:57:05 +0100 jon
Compare this to initial capital embodied carbon and you'll find that structure (when including finishes) accounts for well over 80% of CO2 emissions. This is why I think using initial carbon values is misleading.]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22150#Comment_22150 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22150#Comment_22150 Wed, 28 May 2008 22:29:30 +0100 Mike George Posted By: jonSorry Mike

Edit: I'll try and get Kathy to change it's status if there's enough interest

Only me so far by the look of it - I guess the truth hurts:bigsmile:]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22164#Comment_22164 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22164#Comment_22164 Thu, 29 May 2008 08:19:58 +0100 biffvernon Posted By: Mike GeorgeI doubt that Singleton Birch would be forthcoming with that information either, having tried and failed in the past to find out this kind of data for insulation material. If it were good they would surely advertise the fact.

It also seems that Lime can incur significantly more energy use in transportation to merchant/site than OPC as a lot of it comes from abroad.


On the tour of their works that I went on, they showed us exactly what they were doing and how they did it, including how much gas they used to fire the kilns and how they managed their gas use with changing prices adjusting times of maintainance work etc and the possibilities of alternative energy sources for the future. Since energy is a big part of their costs they are acutely aware of the need to manage it carefully and they really didn't seem to have any secrets.

On transport they were particularly bitter about government rail policy. Much of their limestone production goes to the steelworks at Scunthorpe. There is a railway that actually goes through their site and on to the steelworks but they can't use it as there is no siding and no money for reinstating the siding that was removed many years ago. All the product has to go by lorry.]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22193#Comment_22193 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22193#Comment_22193 Thu, 29 May 2008 11:38:56 +0100 Mike George Posted By: biffvernon
On the tour of their works that I went on, they showed us exactly what they were doing and how they did it, including how much gas they used to fire the kilns and how they managed their gas use with changing prices adjusting times of maintainance work etc and the possibilities of alternative energy sources for the future.

Thanks Biff, Did they give you any figures, such as kWh per Tonne of lime produced in the kiln? Its all very well to say how well they manage their energy use - any clued up manufacturer will do that nowadays, and it's obviously very comendable that they are looking to the future.

What manufacturers don't usually do is put a figure on what they use - As I said, I have tried and failed to obtain such data before. I wait in anticipation for someone in the know to present such hard data.]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22252#Comment_22252 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22252#Comment_22252 Thu, 29 May 2008 18:36:15 +0100 biffvernon Posted By: Mike George
Thanks Biff, Did they give you any figures, such as kWh per Tonne of lime produced in the kiln?
Yes, like I said, they didn't seem to have secrets. Why don't you just phone them up and ask. If they think you are a potential lime enthusiast they will be all the more obliging. They are a very nice firm with a strong ethical basis to their business - not part of some global multinational. Look up their history.]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22253#Comment_22253 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22253#Comment_22253 Thu, 29 May 2008 18:48:10 +0100 Mike George Posted By: biffvernon
Posted By: Mike George
Thanks Biff, Did they give you any figures, such as kWh per Tonne of lime produced in the kiln?
Yes, like I said, they didn't seem to have secrets. Why don't you just phone them up and ask. If they think you are a potential lime enthusiast they will be all the more obliging. They are a very nice firm with a strong ethical basis to their business - not part of some global multinational. Look up their history.


Why not just share the figures with us? :confused:]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22279#Comment_22279 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22279#Comment_22279 Thu, 29 May 2008 23:31:48 +0100 biffvernon Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22281#Comment_22281 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22281#Comment_22281 Fri, 30 May 2008 08:03:58 +0100 Mike George
There are many claims made about the credentials of products, systems, processes etc - from multifoil, ASMET, thermal mass, AGW etc

I agree with Jon and think it is for the proponents of such things to prove their case.

Lime is no different. If a major argument for using lime is the 1Tonne cement = 1 Tonne CO2, and it seems to me that it is, then the most obvious marketing strategy for those producing lime is to publicise directly comparable figures which show exactly how wonderful their product is. I don't see any such figures.]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22282#Comment_22282 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22282#Comment_22282 Fri, 30 May 2008 08:27:33 +0100 biffvernon
Singleton Birch 01652 686000

Ian Pritchett, managing director of Lime Technology Ltd. Tel: 0118 9696949, email: ian@ijp.co.uk. probably knows a thing or two about lime.

As do the good folk at Building Limes Forum, Glasite Meeting House, 33 Barony Street, Edinburgh, EH3 6NX admin@buildinglimesforum.org.uk

You could work it out for yourself with the help of this article: http://practicalaction.org/practicalanswers/product_info.php?products_id=231]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22318#Comment_22318 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22318#Comment_22318 Fri, 30 May 2008 16:10:31 +0100 steveleigh  
He reckons for building walls or plastering a mix of OPC and sand (7 to 1) uses far less carbon than the comparable lime because you would use three times as much lime in to get the equivalent. Both are breathable.
 
Is he right?
 
Concreting is an another story.

Cheers Steve]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22319#Comment_22319 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22319#Comment_22319 Fri, 30 May 2008 16:37:03 +0100 jon
However, it's such a marginal carbon issue that it's irrelevant.]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22325#Comment_22325 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22325#Comment_22325 Fri, 30 May 2008 17:52:07 +0100 biffvernon Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22343#Comment_22343 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22343#Comment_22343 Fri, 30 May 2008 20:29:58 +0100 steveleigh
The old builder is a first class tradesman with almost 45 years experience and he says a mix of 7 parts sand to 1 part lime will not work. He says that 2.5 parts sand to 1 part lime is the equivalent to about 7 parts sand to 1 OPC. Therefore, proving that almost three times as much lime is used to achieve a similar mix.

If you want to save carbon for building and plastering walls use OPC.

Reference : http://www.jiancai365.cn/new_view.asp?id=8477 and http://www.muralist.org/fresco/plastering.html

Also most builders use OPC in their Lime mixes!


Cheers Steve]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22347#Comment_22347 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22347#Comment_22347 Fri, 30 May 2008 20:53:52 +0100 Mike George
My favoured mix is a combination of Sand, OPC and Bagged Lime [6:1:1] Incidentally this is the mix recommended in the BS for external rendering in areas of high exposure.

I have often seen lime mixes quoted as 3:1 If I were to not use Lime at all I would probably go as lean as 5 sand :1 OPC. Your builder must have arms like Popeye to use 7:1.

You make a very good point about this though, and one which is not usually factored in when assessing relative CO2 emissions]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22348#Comment_22348 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22348#Comment_22348 Fri, 30 May 2008 21:27:27 +0100 steveleigh My conclusion is that Lime could initially use significantly more carbon than OPC and this is not including the carbon costs of importing Lime.

They still eat spinach up north Mike!:smile:

Cheers Steve]]> Is it acceptable to use Ordinary Portland Cement [OPC]? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22353#Comment_22353 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1554&Focus=22353#Comment_22353 Fri, 30 May 2008 22:50:03 +0100 Mike George
Is the sand oop North the quarried loamy stuff? that would explain why it is usable at 7:1]]>