The benefits of hot mixed lime mortar

Just a rant about lime mortar. It gets slightly confused with baking bread and psychology but I'm sure you'll get the gist.

[@chrisconboye]

thankyou for your invaluable advice on lime pointing, I've had major issues which your videos have resolved thank you very much.

[@michaeljamesdesign]

Gosh, thanks Chris.

[@FeralKid]

Very glad to see you using hotmix. I've been using it for about 3 yrs now, usually with woodash pozzolan and hardly use NHL at all anymore. Also big fan of hotwash limewashes. Well done, good stuff

[@michaeljamesdesign]

Cheers bruv. Good on ya buddy. Keep up the hot mixing.

[@macoveim2001]

@@FeralKid how do u make a hotwash paint?

[@ianking4713]

Best account on youtube for lime education. Well done

[@michaeljamesdesign]

Kind of you to say so sir. Many thanks.

[@deribrown]

Look back in building history and the old boys never stopped working. I’m sold on hotlime too used not much else in the last year. Nice vid Mike👍

[@michaeljamesdesign]

Cheers Deri. Glad you're in the hot lime. How you getting on with the bleed? Have you done anything on a badly detailed elevation?

[@mmpoggs2033]

Good looking finish!

[@kevinallen9986]

Nice job as usual. My question could or would you use lime mortar on new build brickwork Ta

[@michaeljamesdesign]

I would, yes. For a number of reasons. It's more environmentally friendly than cement, there'd be no need for expansion joints, would look nicer and when the house needed repointing it would be a hell of a lot easier to rake out the old mortar.

[@bendavison8779]

Very interesting video as always. Could I ask which NHL brands have the highest free like content? Keep up the great work.

[@bendavison8779]

*lime

[@michaeljamesdesign]

See Decan Reed at Chalkdown lime. Tell him I sent ya.

[@BenHalifax]

@@michaeljamesdesigninteresting you say his name. Due to your videos and Copsey’s me and my partner have researched deeply and moved into the hot lime industry quite quickly. He made the clear on a post on Facebook, and he was very against us when we mentioned about NHL’s lime content and almost opposed what you and Nigel state.

[@michaeljamesdesign]

@@BenHalifax I'm not as anti NHL as Nigel. There is a need for them and they serve a purpose. There are some good ones.

[@olly1803]

Hi Mike, interesting videos as always. Do you have any preferences between kibbled and powdered quicklime when making your hot mix?

[@michaeljamesdesign]

Kibble for building, powder for pointing.

[@olly1803]

@@michaeljamesdesign thanks for the prompt reply mike - still mild here in Devon which is great!

[@macoveim2001]

What about for inside rendering and plastering​@@michaeljamesdesign

[@michaeljamesdesign]

@@macoveim2001 Perfect. But not for top coat plaster. Use a mature putty.

[@Rageleet]

hey there, Learnt a lot from your videos and thank you for making them. Where do you buy your materials too ensure they are decent? I want to knock the cement render off the front of my 1930s mid terrace as the previous owners got a cream injection to fix damp and covered with cement inside/outside, Completely ignoring the concrete drive causing the issue. :( Cheers.

[@michaeljamesdesign]

Declan at Chalk Down Lime. He'll keep you right.

[@Rageleet]

@@michaeljamesdesign thanks for this, there's some really awesome products here, I haven't come across before, cheers :).

[@matte999me]

Hi Michael. Very informative video. Looking forward to more. I recently repointed the whole of my gable with nhl 3.5 as I hadn't heard of the hot lime method. I hope it will be OK as I now read about the hydraulic limes being stronger than previously thought. I have seen the 2 options of quick lime. Kibbles and powdered. Which would you use on a brick built house (1750's) i would worry that with kibbled the slaking process may not fully take place over the powdered. Would love to hear your thoughts. Cheers matt

[@matte999me]

I have also just purchased a book written by nigel copsey to try and understand further before I carry out more work on the property. I have a cellar to prepare with lime and pointing on the remainder of the property where previous owners attacked it with cement!!!!

[@michaeljamesdesign]

Kibble is for building only for the very reasons you state. NHL can be OK but it's all about its origin, free lime content and eventual compressive strength so you need to go as low as possible. What lime did you use?

[@amyntas97jones29]

@@matte999me If you are in doubt about the ingredients to use, email Nigel Copsey. I have found him only too willing to assist.

[@philomena333]

I mixed 1 part (hanson brand)...hydrated, and 1 part limelite renovating lime, with with 6 sharp sand to it. Is that good for flooring leveling underneath my living room floorboards, im using abit at a time ??? Thought mix best of both worlds together?

[@michaeljamesdesign]

You need to speak to the Limelite manufacturers. I don't use it. Sorry.

[@reconciliation8491]

hot limey)) thanks for the video mate

[@fabienchedal2695]

Hello, thanks for your video, I start "thanks to your videos and others" to make hot lime. Do you only put quicklime in the mixture ?

[@michaeljamesdesign]

And horsehair and pozzolan

[@fabienchedal2695]

@@michaeljamesdesign "Do you have a video on the mix of horsehair, pozzolan, and quicklime? Thank you.

[@michaeljamesdesign]

Not yet. But Nigel Copsey has some material on youtube. @@fabienchedal2695

[@michaeljamesdesign]

kzbin.info/www/bejne/foe6dJeres6noa8

[@Goggleberry123]

your quite right work didn't stop two hundred years ago I have just completed a job with NHL 3.5 December no problems as long as it can be covered and the temperature doesn't drop to silly

[@michaeljamesdesign]

Bang on. Now there’s a man who knows his lime.

[@metallitech]

Do you scrape/cut -back before striking?

[@michaeljamesdesign]

Hell yeah.

[@thomas9429]

You should be using portland cement.

[@marginalgains8477]

Make more videos!!!

[@reconciliation8491]

tell us more about limewash aka whitewash. tom sawyer made it passe. you ever hear of adding pig blood as a dye to the limewash? i have seen others add a bit of hot tallow or lard.

[@michaeljamesdesign]

I'll have a go at some point but to be honest with you there's hardly any call for it nowadays.

[@heriothandyman3148]

Just pointed whole rubble stone gable end in otterbein nhl 5. Have I wasted my time and money and should have gone with hot lime?

[@michaeljamesdesign]

That's a very relative question and perfect for youtube. Otterbein is a very good product and there's actually very little difference in free lime content between a 2, a 3.5 and a 5. They rank as 46, 45 and 43 respectively. In direct contrast, Secil NHL5 has a free lime content of only 14. You can see why Otterbein costs more than Secil. I can't really comment on your mortar though as you haven't mentioned your lime to sand ratio and I don't know anything about the sand you've used. But I certainly wouldn't worry. The end result is you have a high free lime content mortar which is going to be softer than your stone. The problem with NHL is that manufacturers only measure early compressive strength (some as early as 30 days) so we don't know how hard any of them will eventually set. This needs further investigation.

[@tyremanguitars]

when would you use hydralime?

[@michaeljamesdesign]

Internal rendering, as a plasticiser for NHL and to increase the free lime content, for pointing if there was nothing else available.

[@philomena333]

How to make hot lime, like this in vid 😂🤣im dumb dumb, and need to know how to make lime wash with tallam fat🙂 I'm also thinking of using 3sharp sand,1 hot lime, 1 hydrated hanson lime quarter pumice pollazan- near enough something like that. Whats u take on this for motar mix?

[@michaeljamesdesign]

I just use 1:4.

[@tomlewendon4563]

Chilly

[@philomena333]

I made hotmix back in Nov for. N u are right its better

[@Oligoesfishing]

Could you give a new to lime person a simple explanation on hydrated and hydraulic What’s the difference ? Literally just looking it up and found you ! Wow your work is amazing . Inspiring 👍🏻 top job

[@michaeljamesdesign]

I will. I'll do one as soon as I get a minute.

[@johnbyrne8037]

all building lime is Hydrated as it means adding water to quicklime. Hydrated lime can be wet - lime putty - or a powder. There are two basic kinds of powdered hydrated lime. The kind confusingly labelled and called hydrated lime which is dry lime putty, basically, and the kind called Hydraulic, which comes from the idea that it was preferred for hydraulic works such as piers and other structures in wet conditions. It differs from non hydraulic limes - lime putty and the before mentioned hydrated lime - in that it sets by a chemical reaction between various natural chemicals within it which are related to clay that got mixed with the lime back when the stone was laid down. Whereas lime putty or hydrated lime (non hydraulic limes) can only set by the absorption of carbon dioxide which is a much slower process. The science of both limes is more complicated than this as hydraulic also absorb some CO2 and the clay content of limestones vary greatly and so produce a wide range of hydraulic qualities but the manufacturers claim only three grades. There is plenty material on the subject for a long video but in the meantime I hope this helps - sorry Micheal to butt in.

[@michaeljamesdesign]

@@johnbyrne8037 Cheers John, well said.

[@macoveim2001]

Please make a video of explaining hot lime , lime putty , nhl. It s so confusing...​@@michaeljamesdesign

[@macoveim2001]

​@@johnbyrne8037thank u

[@resterationman7347]

Why don't you change to a 1 nhl3.5 1 quicklime 6 sand in the winter Hot lime doesn't stay hot for that long in the winter

[@michaeljamesdesign]

For me to fully address your question you need to state which CL and NHL you're talking about. You've also to state whether the quicklime, NHL and sand are mixed as one or combined later as two separate mortars. On this basis I can only really loosely answer your question. Both NHL and quicklime have a free lime content and adding a binder with available lime to a binder with available lime simply increases the free lime content. High free lime content mortars are more susceptible to cold weather. If you're in doubt then try using St Astier NHL 2 in mid January. That has a free lime content of over 50%. Contrary to popular belief, the set in not accelerated by gauging NHL into quicklime mortar. In fact it works the other way. So much so that in optimum laboratory conditions (ref: N. Copsey) it took 12 months for the mortar to fully cure. Adding the two mutually exclusive limes together introduces two competing forces in the same way builders do when they add cement to lime mortar. It was never this way. If early strength is required then use a CL80 or add the right pozzolan. To address your statement about heat retention. During winter it's sensible to mix small volumes of mortar and keep it in something that helps it retain heat. Covering it also slows down heat loss. but if it's that cold then you shouldn't really be using lime. I'd only introduce NHL into a quicklime mortar if I wanted to slow down the set in summer. If I want to speed it up in winter then I add sand with a small clay content or a pozzolan or I use a good CL80. Hope that answers your question and addresses your statement.

[@Southpoint2019]

Mike Quick question, I’m working with ecoright hydraulic lime, any tips for getting a smooth finish on red brickwork?

[@michaeljamesdesign]

It's a quick question but there ain't not quick answer. I tend not to give out information like that as it has taken a long time to develop my mixes and finishes. I have a guy who works for me and only he's made privy to that kind of information. Sorry to disappoint.

[@Southpoint2019]

michaeljamesdesign I understand, however it would be interesting to talk to you somehow about this stuff, I had a good day I think, guns are a no go but I was brought up on putting it in by hand and my skills have come in handy and I was able to create a flush finish but in 5 hours managed to achieve 5m2 in the wall and finished I have left tomorrow’s mix in the bucket ready for the morning. Would be nice to have your opinion on my work on this particular project ?

[@Southpoint2019]

There is no problem with working in cold weather, a lot of it is timing, We know cement traps a lot of moisture so when it freezes it pops. Working on stock bricks is a dream because as long as you work not too close the ground I have found. I point in all seasons to very good results.

[@Southpoint2019]

I have figured it out now, very good stuff to use if you leave it in a bucket over night. We really need to teach people how to do it correctly so houses are not ruined so I’ll post some videos Monday to help people mix it correctly and then how to apply it without it falling off the trowels. Thanks for responding anyway though

[@michaeljamesdesign]

@@Southpoint2019 Don't forget to mix fresh every day when you're working at the bottom of your wall.

[@jackwardley3626]

well if your a sole trader and you only got exterior work you do it whenever you can't pick and choose got to make a living

[@ricdavid7476]

"now then now then " that was a jimmy saville saying yikes!!!!!!!!!!!!!!!!!!!!!!!!!!111

[@michaeljamesdesign]

Aye, a saying that he nicked off the lads up north. Of which I am one. And we still say it. "Now then".