So it's still as clear as mud then.

Well hush ma mouth!

You're still confused. For render coats and under top coat plaster you can use NHL3.5 with sand. but not at this time of year

​@@michaeljamesdesign Thank you for your reply. Yes, I am confused since nearly everyone has different opinions about lime on the internet. For render coats, should I add extra lime to NHL3.5? Like 1nhl:2lime:2.5 sharp sand. If so, should it be slaked lime from quicklime or putty or lime hydrate. Thank you again.

@@Hanokei Did you see that I replied and suggested NHL3.5 with sand?

@@michaeljamesdesign Yes I saw. In the video you were talking about adding extra lime to increase the lime percentage of NHL. I thought I could apply the same idea to rendering. That's why I asked about it. I think you were talking about top coat plastering only then.

@@Hanokei Oh OK. I wouldn't add lime hydrate to NHL for outside. Only inside. When you say extra lime you must be absolutely specific about lime. Never just say lime.

Oh dear, my bad. Did I really say that. I should've said something like 'Once this lime putty has been allowed to mature for a while you'll have mature lime putty'.

@michaeljamesdesign it made me laugh, brilliant video though. Full of insight and knowledge

Much of what we have had to go on to help us understand the way lime was used historically has all been bushels, sacks, pints and gallons. Aged recipes refer to aluminum sulphate as alum and it's expected of those who work with limes and colour-washes to know about traditional terminology. It's to be understood that a pint of ale can be used as a mordant and that a high clay content sand can be used to help set a lime mortar. How much you use is up to you because lime is all about feeling your way. It's like learning braille or swimming. You can only science it to some degree because it's a very inexact trade. But it's like all traditional trades and crafts, they all stem from knowledge gained many years ago and you learn by taste, smell, feel and sight. What works for one person in a particular environment might be a big mistake in another. What does work though is research. There's a lot of doctoral research which has provided evidence enabling us to understand historic mixed. Particularly in places like Israel - see Nigel Copsey. It's all out there and isn't too difficult to find - if you're prepared to do your spade work. If you joined the Building Limes Forum or searched for academic articles written by Dr G. Lynch then you'd certainly be able to understand lime plastering from a mesh size perspective.

@@michaeljamesdesign Thank you for your reply, I'll look for those links you mention. One aspect of all topics with extensive arcane language and terminology is that for experts it is so difficult to "unlearn" and see something from the position of the totally ignorant novice. This is where a good sciency reference book would help. It may exist but I've not found it. This does actually apply to ordinary cement mortar mixing too.

@@ianwhisson8064 You'll never get a good sciency reference book for lime in the same way you won't get one for roofing. But you can buy Dr G Lynch's books on Gauged Brickwork. You can also can buy N. Copsey's book on hot mixed mortars on Amazon. That's written off the back of a Masters dissertation. You can assemble a small library and that'll give you a start in the trade. Same for plumbing and electrics but if you're really intersted then go and do a practical course. What you're trying to do is the equivalent of trying to master the English language fluently after having only learnt English grammar. Learning just doesn't work like that.

It's all fine

I do

You can but there's no guarantee of freshness. Not fresh = instant failure. And the workability and finish won't be as good as other limes.

I have found some quicklime I can get. I believe I should make it into a slurry with water and leave it to slake for three months. Then I will have lime putty? Also will paint type buckets with lids work? Thanks again.

@@standleyt Yes you can slake the quicklime to a putty if you like and leave it for 6 months to mature for top coat plastering. But it's not something I do. I'm not expert concerning bucket lids. So I can't be very much help with that question. I'm sure there are plenty of tubs with lids on ebay.

I thought you said that you slake your own putty. If so, what method do you use? I think the initial heat will melt the plastic bucket. Thanks.

@@standleyt I slake my own lime but it'd done as a hot mixed mortar. And yes, you're right, it would melt a plastic bucket.

Trass: crushed volcanic rock. Pozzolan.

@michaeljamesdesign thanks very much, im a plasterer looking ti get into doing lime work. Doing the second part of a coarse next month.

@@neilrollason Well done bruv, as an existing spread you should do really well. There's so much work out there for good lime plasterers.

Thanks for the support 🙏 any bullet points tips,much appreciated 👍im in Coventry, hopefully will get work in surrounding areas, villages etc.

@@neilrollason Make a scratcher out of old lath. Don't use one of those combs.

Mikey 😅😅😅👍

@@michaeljamesdesign it was a fascinating and amusing piece. This lecture and Nige's presentation in the Holy Land (parts 1&2) are, I believe, the most informative audio-visual references currently available to mankind, in terms of Lime and its correct use - precious resources indeed! Merry Christmas to both you and Nige!

Might be best to speak to someone who can give you a detailed pre-emptive condensation report.

@@edzardw6450 I did one but the lime was old and took ages to slake solidified. But I’ve got some newer stuff so it won’t be too long.

You're most welcome, thanks for commenting.

We did

I'd be tempted with a nice NHL2, some sharp sand and some plastering sand.

@@michaeljamesdesign thanks for getting back !!

Dry hydrate is less workable and doesn't offer the same finish. For your second question you will not get a putty mortar to cure in winter whereas hot mixed mortar can be used throughout the year. Putty mortars also have less available lime because there is no expansion.

Thanks very much for responding, great to get an answer to this 👍

Not too sure I understand what you mean. Explain your intention on more detail.

Use 1/1/3 quick lime( calbux 90)to Saint astier 3.5 to sand

Use 1/1/3 quick lime( calbux 90)to Saint astier 3.5 to sand would the be a good bedding mortar

@@gilvaughan-m8r Sounds like what you're saying is that you want to add a whole gauge of quicklime to an NHL mix. Or vice verse, one gauge of NHL to a gauge of quicklime. If so, why would you want to do this?

I’ve had a problem with a purely quick motor cracking and in other times it was too wet and I’ve got quick climb left over from previous jobs so I was wondering if I could use it

You can't.

The same question could be asked about those poor people who have shares in British Gypsum. Lime mortar doesn't actually breath as the infers a gaseous exchange. What you have is moisture laden air which is pulled under pressure along a minute bridging network facilitated by drying pores situated on the outside of the pointing or rendering mortar. Rather like transpiration. So when cement - which has no capillarity - gets wet then it becomes saturated and you get damp. Glad you're taking an interest - you're correct about the moisture balance.

Sounds great!

Hi there. I can't really help you as I don't use cement. All I can tell you is that it's bullet hard and impervious to moisture. Which means it shouldn't really be used for straw bale housing. This is probably why it's only lasted 20 years. It should last up to 10 times longer.

@@michaeljamesdesign ​​⁠ I was told that straw bale home walls must be replastered every 15 years. Cob homes do not require such maintenance, but straw bale homes do. My main question is not about ingredients but the steps/sequence of mixing them I did. Thank you for your reply.

@@oldworldwildona550 Why would they need plastering every 15 years?

There were visible wear and tear ... some micro cracks around windows and at the bottom of walls which had most exposure to sun and rain. Some walls looked good while others required to be resealed.

@@oldworldwildona550 The cracks were likely caused by the fact that the cement made the render brittle. You need a flexible mortar. No cement.

You can but there wouldn't really be much point.

"Nonsense".

Lots. Up to 90% of a gauge sometimes, depending.

It's all about the free/available lime content. You need to look at the data sheet. You also need to know whether it's 2, 3.5 or 5. Hydraulic lime mortar is like beer, tyres, tea and meat. It's like me inviting you to dinner and telling you you're having food on a plate. Do you see what I mean? Guess what? You're going on holiday, have bought a house, getting married. Would you not agree that you'd want a modicum more information before you embarked on any of the aforementioned pursuits? Same with lime.

It's not rocket science and it sounds like you'll probably do a better job

Now.

Happens naturally.

@@michaeljamesdesign I read a paper that studies the properties of lime-mortars in relation to the type of slaking that was used. The paper concluded that air-slaked lime yields the mortar with the best qualities. That conclusion took me by surprise. I work with powdered quicklime exclusively and I find that slaking is not always a super straightforward nor consistent procedure. Sometimes I add a certain amount of water and it heats up immediately. When I add the same amount of water to lime from a bag that had been open for a few weeks, the reaction is much slower. It takes 5 minutes before the water warms. Another thing I noticed, I always make milk of lime which I add to my earth mortars, is that if my water boils during slaking, the lime will clumps together. Apparently slaking above 100°C creates crystals and reduces the plasticity and surface area of the lime particles. Industrial slakers are recommended to run between 80° and 90°C. The close the lime is slaked to boiling, the higher the quality of the slake. But over 100°C and there are diminishing returns. I prefer to make milk of lime and not exceed 100°C also because there won't be any toxic fumes, which is an important consideration for as I often have to mix indoors. Just some of my observations!

@@DeWarmePlakker I find the same with lime which is getting a bit older. But usually it's got to be a couple of years old before the slake time increases. I made some lime wash a while ago and it set sold after I was stirring for about 5 minutes. I think the amount of moisture in sand might have something to do with how much water we use. The brand of lime is important too. Calbux is immediate and instantly hot, but Otterbein and Lincolnshire chalk lime take longer.

@@michaeljamesdesign I use Supervical from Carmeuse here in Belgium. I'm quite lucky it's an agricultural product because I don't think I would've found any quicklime in Belgium at all!

Plenty of pozzolan or NHL mortar.

@@michaeljamesdesign I have Secil 3.5 - thanks!

Learn some patience.

Air flow is so important. It's half the battle.

Sounds like a good man.

I think what you're trying to say is that you can add pozzolan to non-hydraulic (air) lime to give it a hydraulic set.