Lime mortar repointing over common earth mortar, Aston, Oxfordshire

[@jobjobbed8459]

Can you do the pointing in the winter, I thought it had to be done in dryer weather?

[@michaeljamesdesign]

You can work all year round. But mid-summer can be difficult. Best to stay away from south facing elevations in June/July.

[@tablettwentytwo1750]

Hi Mike. Another informative video. I queried with you recently regards my garden boundary wall. You correctly identified it as being of a sand and earth construction, to (presumably) allow for flexibility. It has had various patch/pointing work done to the bed and perp joints throughout the years. Again, through watching your videos, I have embarked on a hopefully sympathetic re point of the wall. The question or worry I have is thus: when raking back the brick, should I have replaced old, dried earth and sand mortar with like then finished with NHL 2 pointwork? The first section of wall I've backfilled and point finished with 3.5 St Astier. I fear now, this may well be too strong for a wall that has been up for 120 years with earth and sand as a binder. Should I backfill with earth and sand binder and point with St Astier 2? As I stay in Glasgow, St Astier seems the better of the bunch from my local stockists. However, I do realise I may be well off the mark with my theorising.... Regards. Les

[@michaeljamesdesign]

Earth mortar was, and still is, used because it was/is very economical. Using sand and lime to build a garden wall would have made it more costly. Why import sand and make lime just to build with when you're standing on an abundance of appropriate materials? You can make your own earth mortar if you like but most people wouldn't bother because it's now easier and less time consuming to import materials Don't worry about it.

[@ashestoashes3107]

Great video. Couple of questions please sir if you could answer. Im currently renovating my 1935 bungalow. (No cavity). Going to knock out the bay window / and brickwork extension which was roughly done 40 year ago with sand and cement and take it back to original lay out. What lime building products shall i tell the bricky to use when rebuilding this part of the house with bricks? Thank you Sir

[@michaeljamesdesign]

They'll have probably used quicklime with cement but I doubt you'll get a bricklayer to use that.

[@ashestoashes3107]

@michaeljamesdesign thanks. I've been informed/ recommended by the guy who is going to lime plaster my internal walls not to use traditional sand cement materials on the bricks but only lime. Would you recommend which type of lime to use please on external brickwork? Thanks

[@michaeljamesdesign]

@@ashestoashes3107 Sand and cement isn't traditional. And it's not so much a question of what I'd use as I'm competent with all limes and there are a few options for you. It's more a question of what lime your contractor is familiar with - what does he use? Find that out first.

[@ashestoashes3107]

Yes I meant to use the word 'commonly ' today's way of building instead of the word traditional. Hes used 0.5 parts hydrolised lime. My question is also please is what products would he or can you use traditionally use just to build that outside wall in my house. Can ulyou use hydrolised lime and 1 part white cement ? Anything else needed? Appreciate your valued knowledge. Thanks

[@michaeljamesdesign]

@@ashestoashes3107 There's no such thing as hydrolised lime.

[@paulpearson4613]

Very helpful videos Michael. We have recently bought a stone cottage in west wales. I have seen it on an old map as far back as 1806. It has a large inglenook fireplace which has the large arced beam. The stone on the exterior wall of the fireplace needs to be re-pointed and the stones look a little dry and flaky. Is there any advice you would give for such a job (ie materials recommended?). Also the whole cottage has an exterior pebble dash (which I guess from your videos is a huge no-no!!). We are thinking of getting the front wall of the house bought back to stone. This would be the correct thing to do (but costly) right? - Makes me worried in case the stone work is damaged under that cement/pebble dash or whatever it is. The cottage does look nice, but I am worried it isnt doing the house any favours with the pebble dash. Look forward to your next videos! Thanks :)

[@michaeljamesdesign]

www.amazon.co.uk/Hot-Mixed-Lime-Traditional-Mortars-ebook/dp/B07NHF221C

[@paulpearson4613]

Thank you for the link. Have you had any dealings with removing a pebbledash/harling finish from a stone walled cottage stripping it back to stone? This exterior render seems common here but also seems wrong

[@eohohomeeducation260]

@@paulpearson4613 roughcast is a traditional west wales finish. As long as it is a lime roughcast not a cement roughcast. It is the best finish on your west facing wall. Where the weather comes from.

[@paulpearson4613]

@@eohohomeeducation260 do you have any tips on how to identify it as lime based? It would be reassuring to know. Many thanks and merry Christmas!

[@eohohomeeducation260]

@@paulpearson4613 hello, if you can pick it off with your hand and it crumbles it’s probably lime. We have some original roughcast lime from 1847 on our “pine end” (gable end). Under the eaves and at the bottom. If you hit it with a pick or chisel and it’s really hard it’s probably cement based.

[@damo83frank39]

Would you have any issue with lime mortar using hydrated lime for pointing stonework

[@michaeljamesdesign]

None at all. Lime hydrate has a very high free lime content but it must be used fresh otherwise it won't set.

[@krakenhackenla]

Any tips on how to prevent lime bloom/effloresce? I built a garden wall using brick and a hot lime mortar, but there are two spots with white staining. Ok for a garden wall but not for a house.

[@michaeljamesdesign]

What's your detailing like?

[@krakenhackenla]

@@michaeljamesdesign not too sure what you mean by detailing. The lime bloom is only in two small areas but the mix was 1 quicklime to 3 sand. I did flush joints which when had gone firm(ish) I compacted with a piece of wood removing any cracks in the mortar, I then finished with a churn brush. I used washed sand with good grain variation. Thanks for the reply

[@michaeljamesdesign]

@@krakenhackenla The detailing i.e. coping etc. And did you use power or kibble? And was it a stone wall. I can't say much if I can't see it.

[@krakenhackenla]

@@michaeljamesdesignreused red brick, wall knocked down and rebuilt, bricks dampened before being laid as they are quite porous. Calbux 90 powdered quicklime, dry mixed with the sand first then water added. All mixed in wheelbarrow by hand. 6ft wall with coping stones on top. Wall was protected from rain, and lightly dampened to stop it drying out too quick when needed.

[@michaeljamesdesign]

@@krakenhackenla That's no mean feat by anyone's standards. You ought to be proud of that. It sounds like you might have had hot spot or pop out. The only thing I can think of is that there was lump in the powder which didn't slake fully. The guy to speak to about it is Nigel Copsey. If you can get a reply from him then his will more than likely be more informative than mine.

[@Tom-hl7wc]

Can you mix the mortar in a mixer? Also is there a particular manufacturer or quicklime you recommend? I want to repoint a stone wall here in Snowdonia.

[@michaeljamesdesign]

Roller pan mixer. Not a drum mixer.

[@Tom-hl7wc]

michaeljamesdesign thanks for getting back. I’m completely new to lime mortar so trying to get my head around it and do the right thing for our cottage. We are on a tight budget so I’m doing it myself. I’ve seen other people mixing nhl 3.5 in a normal cement mixer. Is that ok? Or are all lime based mortars unsuitable for mixing like this?

[@michaeljamesdesign]

@@Tom-hl7wc Roller p[an mixer for hotmix. Drum for NHL. Try this for putty: kzbin.info/www/bejne/rInWlK2YrdlqhtU

[@pennyfulton3418]

Great video , very wise . ...wondering though, when you say, '' 'LIME mortar ' over ' common EARTH mortar ', .''.... Are you saying that the ( new ) lime mortar would be differently constituted in any way, to the way old ( lime ) mortar had been made ....? ( Obviously modern cement being a different thing altogether, from either one ) ...

[@michaeljamesdesign]

Not quite sure I understand the question Penny but to clarify: common earth mortar is very weak and friable and won't stand against the weather so it needs a porous and flexible lime mortar over the top of it. That's the way many houses were built. You can use NHL (I use NHL 2 when and where I can) or lime putty (A bit weak. Originally used for internal fine plastering). Ideally a hot-mix would be specified but I leave that to my customers as some people don't feel very comfortable with mortars that reach boiling point in their back gardens.

[@pennyfulton3418]

@@michaeljamesdesign Ah , Thankyou . Yes , After I asked that, I realized there was a sequel to this video, after watching that all became clear ...and a lot more besides . I've been researching the subject of the alleged eg chronology and methodology of building / brick making ; limestone 'burning ' pre kilns ; as well as straw bale and wattle and daub and mud etc. There seems to me to be a lot of anomalies in the narrative once one starts to try to put all the various factors together ....added to which your videos provide a whole other rich vein of technical and practical knowledge and food for thought ...I'm going to start on the next lot tomorrow, starting with, I think it was the detail of all things wattle and daub ..... sub'lime ' . Sublime !

[@michaeljamesdesign]

@@pennyfulton3418 Sublime! Sounds interesting. During your perambulations do consider this: there are many people trying to take things back to the way they were with lime i.e. using hot-mixes. Modern methods for producing quicklime aren't the same. They're super-efficient, clinically clean and therefore produce uncontaminated lime. The impurities which were once present in stone kilned quicklime (which was a mixture of extraneous variable including lime burnt at different temperatures) is lacking. Ergo, so is the authenticity. A 25kg bag of Calbux CL90 aint nothin like a good home burnt quicklime used to be. Modern day equivalents are only a reflection of the soft lime putty found on properties built yesteryear. The only real way to do it is to set up a home kiln and fire your own chalk lime.

[@pennyfulton3418]

@@michaeljamesdesign That's kind of the reverse of what I'd gathered ! No wonder it's so difficult to unravel old low tech , technologies without long first-hand experience . Eg I read that, ' limestone, ( uniquely ) when heated could be turned into a paste by adding water, which in turn when dried out again, turned back into the same stone formation ( of whatever kind ) it started out as' . Sounds straightforward enough ..... But from what you say : 1. The aim may not necessarily BE , ' to reproduce an exact copy of the original / nor all the same characteristics ' . 2. The 'purity ' of both the source and the processing aspect, is also just part of the modern ideological concept of isolating the 'active ' ingredient ( in this case 'lime' as a chemical ') having been superimposed onto, in fact better-for-purpose , practice by experience , handed down through countless generations . So , as a matter of fact, heated limestone is the important ingredient : not ' the lime' at all ! . And moreover so called 'impurities ' are irrelevant ...and can be essential to best practice . Hence the expression : '' SUBlime'' meaning 'the ultimate good ' ...As in , BEFORE having been turned into the aberration : chemical lime .... Think I've got the whole picture sorted now ????

[@btripin247]

You are completely correct but I bet the homeowners going to be pissed when they see this video though... and you're the messenger!

[@DaddyBear3000]

This is exactly what someone has done to our property. We have three floors of ruined walls that need so much work 😞 Massive job. I don’t even know how much money and time it’s going to cost to fix.

[@michaeljamesdesign]

I feel your pain.

[@lina-zz9kk]

cheers