How to mix lime putty mortar

Here we explain how to mix lime putty mortar, with sharp sand. This will achieve the best performance, longevity and workability from the mix.

[@lesleywhiley1594]

You’re a brilliant Porter instructor thank you for this lesson I now feel confident enough to open my tub of lime putty and get on with the job.

[@brianoneill350]

Super job, really clean mixer sign of a real pro. Make sure you charge as much as you can as lot of knowledge and expertise. Not many people can work with this level of expertise and professionalism

[@Pavlo_S.V.]

Great video, very well explained. Thank you for filming and talking through such aspects of the jobs you are doing.

[@katsiamapoisoning786]

Another informative video delivered with enthusiasm and style. Might even try my hand at it on my 110 year old brick building when I get up enough confidence.

[@amyntas97jones29]

Excellent, I've learnt a lot from Porter's videos.

[@stevepicchi8986]

Thanks for another quality video!

[@billyclegg3084]

Thanks for the Masterclass...👍

[@XTrueXAlucardX]

Really helpful videos these mate. Iv been on a introduction lime course recently as im a plasterer getting into Lime work. You seem to break it down a-bit better when explaining it. Find your videos really helpful, and you seem to have a laugh while doing it! Keep the videos coming mate looking forward to your next one🙌

[@dportercontracting9974]

Cheers for the props on the vids matey. Glad to hear you are making the jump from gypsum to lime. The square meter price is way higher for lime plastering. It's a much gentler, forgiving medium than gypsum.

[@matthewsmith2040]

Thanks for the video, v.helpful!

[@diogenes1815]

That’s some nice looking lime putty you got there.

[@0044512]

Really enjoy your videos.

[@davidleach1592]

I'm amazed he has just 168 likes, this guy is gold dust!

[@2_shoes]

Great video porter, can you post some of the wall which your working to give us an idea of the time for it to set and the finish on your pointing. Its always good to watch a tradesman that's enthusiastic about his work 👍

[@dportercontracting9974]

Thanks @2shoes. There will be a video of the finished pizza oven online, next week when we are back on site.

[@sgfelectrical734]

Keep the vids going👍🏻

[@spoonerbooner]

really helpful thanks, doing my cellar and info. really helped. cracking locks btw.

[@NicHills]

very helpful, thanks

[@bartoszrypysc7481]

I make hot mix in my cement mixer . All the paint went off that mixer due to how hot it gets during slaking process . Mixer still works though. Great videos

[@davetofield9982]

Very helpful thankyou

[@youubik]

Excellant video

[@atroutflycrazy8057]

Love your vids pal, pan mixers are def expensive, i just had to buy a small mixer again , 1st day of mixing with lime and come evenin 2 inches of mortar stuck to sides, its a scraping match for 10 mins to get it clean. My last mixer the fins broke off yrs ago , best thing ever happened , was so easy to keep clean n stick shovel in to scrape any dried mortar .On such a small drum fins are pointless , Fins on my new 1 will be comin off too .lol

[@edinburghwheatgrass8106]

Hi that's really helpful. I'm about to embark on my project repointing my derelict(as yet) cottage. I bought some putty with the sand premixed in it and am guessing it'll be cheaper if I buy this stuff and mix it up myself. I have masses of walls to do so these considerations are kind of important right now.

[@dportercontracting9974]

Hi thanks for the comment. You live in a beautiful city that is the home of stonemasonry. Mixing yourself will be a far cheaper method of pointing your cottage, over buying in premixed. You will usually find that the estimated coverage on the tubs won't go just as far on the wall. If you would like some key information or advice near to you then get in touch with the Scottish Lime Centre Trust, at Fife. I've done several of their courses in the past and highly rate their ethos. Masons Mortar near to you are a quality heritage supply firm and their products are second to none. They even provide a service to match your existing lime mortar and make a like for like mix. Hope this helps?

[@socialmobility3568]

Just watched a stack of your videos & learnt so much, thank you. Can you please share a little more info on the granite dust spec? When I google 'granite dust' there is a broad range of products. Thanks

[@dportercontracting9974]

Hi, glad you found the videos helpful. The granite dust that we use is a 6mm-dust. It comes in a variety of colours, depending on your supplier.

[@MargotCottam]

I am hopeing uou are not too famous now to reply . You videos have inspired me to maybe tackle my victorian brick house myself. It has been repointed in the past with cement and it is destroying the bricks. (Not by myself). Would this mix be suitable for repointing brickwork Will practice first on the brick garden wall. Any advice would be greatly appreciated. So much conflicting advice out there.

[@dportercontracting9974]

@@MargotCottam Hi Margot, I have just returned from a weekend at a festival so it will take a day or two for my brain to arrive back in my head. A lime putty mortar on brickwork would be good to use. If the weather is more inclement at your property, then an NHL mortar may be more beneficial as the addition of Argillaceous clays add a degree of water repellency to the mix. It would be a good idea to start on your garden wall before tackling the house, until you get the feel for using the mortar.👍

[@kingofthetrowel1725]

Nice one mate 👍 would you say that nhl limes are less breathable than a lime putty, suppose the 2 are deffo better than cement on an old stone building 😭 I’ve seen it loads builders lashing cement strap pointing on and killing the stone 🤦🏻‍♀️🤣

[@JohnDoe-wo6hl]

Hi Porter, great video as always! Where would you recommend getting the sand from? Im worried about buying the wrong stuff. Thanks and keep up the good work :)

[@dportercontracting9974]

Thanks John! Your local builders merchants should have access to a sharp sand. Washed river sands are always a good shout for a quality lime mortar. Have a look on limestuff.co.uk for a selection of decent grades of sand. (If you are UK based, that is..)

[@davidwood8837]

Would you recommend adding a pozzolan? Great video as always

[@dportercontracting9974]

It depends on your application of the mortar. If you are building with lime putty then I probably wouldn't put a pozzolan in the mix. I tend to add it to a pointing mix of NHL 3.5 or less though.

[@MyMiaTom]

Many thanks for this video! I want to plaster over the walls in my bedroom... The wall is a cinder block wall that was painted with acrylic paint ... Do you think it is possible to have the benefits of old traditional lime walls in a modern built home?

[@dportercontracting9974]

Hi Maho, I wouldn't advise skimming over any non permeable membrane with lime. Ideally any plastering done should (in my opinion) be knocked back to the brick or block and given a weak limewash prior to plastering. This aids adhesion to the plaster coat and reduces suction through the mortar. I'd be tempted to try to remove as much of the acrylic paint on the blocks too, prior to application. I think there is always a place for traditional lime work in any home. Modern plasters and painta contain all manner of nasties in the form of VOC's and other chemicals. Lime work and natural paints produce a far healthier environment to reside in.

[@MyMiaTom]

@@dportercontracting9974 thanx so much for your reply! Love your work. I will try as you said to make one wall and will continue section by section to do all the house. In Israel (where I live) the transition to lime is slowly coming ....

[@deribrown]

Definitely going to be using the word carbonification!

[@dportercontracting9974]

Ha! It flows like honey of the tongue and does exactly what it says on the tin..

[@foesure]

Carbonisation I think

[@deribrown]

Or carbonate

[@gulag8735]

Hi Mate, I've a stone cottage plastered externally with sand/cement, causing me huge damp issues as water is getting in through small cracks. Is this the mix you'd use to replaster externally? Thanks

[@dportercontracting9974]

Hi Gu Lag. A rendering mortar could be used from a lime putty mix however, I would be tempted to use an NHL as the clays in the lime would add to the weather proofing in the finished set of the mortar.

[@midnightbass681]

Hi porter. Just discovered your videos and what you do is great. I have been offered a job repointing an internal wall for people I've worked before and they really want me to do it rather than someone else. I've done a lot of pointing for the company i work for and love doing it but always used white cement. I never used lime mortar and the customer requested lime mortar. What kind of mix would you use for internal pointing? Cheers

[@dportercontracting9974]

Cheers for the props Midnight Bass. Internal pointing sand can be a more medium grain sand. Have a play around with some mix ratios on a job and see what colour of mortar and effect the client prefers. Lime putty based mortars, cure to a brighter tone than NHL based mortars. For internal pointing, I tend to use NHL based mortar with the same mix used for outside works. The granite dust shines through in the finished set. Good luck

[@midnightbass681]

@@dportercontracting9974 thank you very much mate , I'll have a play at work , make different samples of mortar and see what they prefer. Roughly how long after applying the final pointing do you rake it back and brush it off?

[@dportercontracting9974]

@@midnightbass681 It depends entirely on the humidity around the project before the mortar is "green hard." If you can just indent your thumbnail mark in the mortar, it should be somewhere near.

[@Truman77.]

I have an internal cavity wall to brick up where there are several holes. Can I use lime putty mortar in November? Or is it best to leave until April?

[@dportercontracting9974]

If the internal worksite is sheltered from frost or temperatures below 5c then you can use the mortar right through the year with no fears of degredation of mortar.

[@pmd7914]

G'day. Is your mix ratio suitable as a brick mortar? Can the dry mortar be removed from bricks and reconstituted for teaching, cost saving? (We do this with 6 sand : 1 dry lime mortar.) Thanks m8 🇦🇺

[@jimhud134]

How long does lime putty mortar normally take to harden? We put it on two days ago, and it still feels a little squashy.

[@dportercontracting9974]

A putty based mortar will take longer this time of year while the temperatures are cooler. It could be anything upto a week or ten days before it gets to that green hard set. Bear in mind that a putty takes longer to cure than an NHL mortar too.

[@danny-rj6dh]

Hey first of all super nice videos:) I'm living in Spain on a project where we made a huge amount of putty from bags of quicklime(no number on bag) This was 2 years ago Besides that there was no info on the bags. I used it on smal projects mixed with sand 3/1 and it got super strong over time. Watching all you're videos I got I but confused about if this will be the right line putty for pointing the old stone structuur (100 years) or not? Thanks already cheers

[@dportercontracting9974]

Hi Danny, thanks for the props! Sounds like you have an exciting project on your hands. It's always an honour for a craftsman to look back on his work bringing an older property back to life using traditional methods. Top work matey! The quicklime would need slaking in water to turn it to lime putty. It's always advisable to leave it covered in water or an airtight container for at least four months. This ensures that all the lime has slaked properly and vastly improves the malleability of the mortar when eventually mixed up.

[@dportercontracting9974]

Lime putty would be great for use in pointing where you get more sun and heat rather than rain. NHL lime has agrillacous clays as a constitueny, which improve water repellency.

[@danny-rj6dh]

@@dportercontracting9974 thanks for the fast reply! Helps alot I'll start pointing the huge building in a few days and you're videos helped alot to prepare for it

[@dportercontracting9974]

@@danny-rj6dh Cheers bud. I'm glad the videos have been of service to you. We have another video series going up this coming week of a lime pointing project we have been working on up on the west Coast of Scotland. Keep your eyes peeled for it!

[@daleburns7110]

Can I please ask how you got into this kind of work? Did you start off working with new materials or always worked with traditional materials……..I am wanting to find something I’m interested in to retrain but not sure how I could do this. Thanks

[@dportercontracting9974]

Hi Dale. I started off dry stone walling when I left school. That led to an interest in lime work as the two come hand in hand with construction styles. Did more than a few years in general construction, specialising in stone work and masonry. Spent a while working for a heritage construction company. That's where the skills are honed, when working with lime 9n a daily basis. There are some great courses up and down the country that address all aspects of lime construction. Have a look online. Practice on you own or friends properties or even consider approaching a local lime practitioner to work alongside a craftsman at his trade. Hope this helps?

[@daleburns7110]

D Porter Contracting thanks for the help! I think I noticed you are Lancashire based? I am Manchester and so is there any courses local that you know of that you would recommend. I maybe pushing my luck but wanted to look more into it 👍

[@hbpw857]

Hey porter is this any good for pointing a brick chimney

[@dportercontracting9974]

It would depend on the integrity of the stack, weather exposure, quality of raking out of joints/application of mortar. At least one of the sides of the stack would be getting some hard weather so I would look into adding a pozzolan to a hydrated lime for a stack pointing. Hope this helps?

[@hbpw857]

@@dportercontracting9974 thank you for reply I’m in two minds I might just go with nhl 2 and keep my putty’s back as they been curing for 2 years now

[@dportercontracting9974]

@@hbpw857 putty would be better for a constructional lime or plaster. Save your aged, creamy hydraulic lime for a more suitable project. It will be lovely stuff to work with at 2 years old.

[@sc-ty7zs]

Which area in Yorkshire do you cover please?

[@resterationman7347]

Lime putty is 50% water Done by volume not weight Read the instructions

[@dportercontracting9974]

Thanks for your opinion fella.

[@eddieharding2432]

Your mixer is going too fast, get a petrol one and just have it ticking over . It is quicker .

[@ironimp1]

I think you have done a good introduction and presentation, but I am really sorry to have to say that you need to take the video off KZbin because your mix is 6 to 1 and not 3-1 as you claim, this is because your lime putty is 50% water. Please do another video as you are good on the presentation side.

[@roman8133]

Agreed, great video and presentation, but ironimp1 is correct and 6:1 would be the correct mix definition due to the water content of the lime putty.

[@ironimp1]

@@roman8133 I don't want to seem pedantic, but if you measured the void ratio of the sharp sand that you are using, you will find that you should be mixing as 2.5 to 1 lime. Therefore if you are using putty the mix will be 1.25 sand to 1 of lime putty.

[@roman8133]

@@ironimp1 Yes I agree with ironimp1, the mix should be 1.25 sand to 1 of lime putty mixed by volume. If you are in any doubt of the correct mix when using lime putty, call the SPAB technical line which is free of charge and offers sound advice as a recognised authority.