How to Repoint Failed Lime Mortar in Historic Brick Pt. 1

In this video I show how I repointed a section of the foundation of my house with Type O mortar to replace lime putty mortar that failed due to rising damp. I discuss the pros and cons of repointing historic brick with anything other than lime mortar and the circumstances that made me decide to use Type O mortar. This how-to video should give a homeowner faced with repointing the confidence to undertake the job and save a huge amount of money compared to hiring someone for the job (who might use even harder mortar) . I was able to achieve excellent results with minimal tools. The second video shows more detail on the actual repointing process than this one does so watch it for helpful tips.
Since making this video and the Part 2 video, I have sworn off using Type O mortar and now exclusively use NHL3.5 for my repointing. Any concerns I had with it deteriorating in rising damp situations are now assuaged. They videos on using Type O still are relevant in terms of technique and procedure. I recommend watching them but disregard the mortar mix advice. Click here to watch the video on repointing with NHL 3.5: • How to Repoint Failed ...
Here is a link to watch Part 2: • How to Repoint Failed ...

[@ne8r]

Will be using Type-O to repoint marble steps. Seems like a good hardness for 1800 psi marble. Am concerned Type-N will get to strong over time.

[@MrDziuka]

Hello, I recommend to watch Nigel Copsey on you tube. About hot lime mixes and he talks about nhls too. Lime putty in the past was predominantly used for indoors. And on the outside hot lime often with some pozzolan added. And this can last. You just didn't make best choice of mortar, i think. NHL can cause damage too, often buildings pointed with NHL are permanently wet for some reason. Not enough capillary action apparently. Regards

[@johnhendy1281]

So helpful to see this technique. I don't think I can use portland cement for my case as they apparently don't breath the same, but nevertheless... just seeing someone pack joints and finish is really great vs. just reading about it! Thanks for taking the time to make this.

[@wickedmessenger1]

NHL 3.5 is probably the way to go for you. It sets up just like what I used but it has the benefits of lime mortar -- breathability, self-healing, and sticks to other lime mortar. It's significantly harder than Type O mortar so I decided to go with Type O mortar. I'll see if I regret it later. For now, everything is looking great. For the last of the repointing work I'm going to use NHL 3.5 and compare the results over the years. I'm still not sure how it will hold up against rising damp.

[@wickedmessenger1]

In the second part of this video I show a lot more of the process than in this video. This first video skimped on the technique. I think you'll get a lot out of watching the second one. There's a link in the description above if you click on "show more."

[@johnhendy1281]

Where did you find hardness values? I have pretty soft stone, so the force of the mortar on it is definitely a concern. Everything I'm finding says O >> NHL (see link in comment below). Here's another, see pg 43. Both compression strength and hardness are both shown as lower for NHL: - www.ncptt.nps.gov/wp-content/uploads/1999_02.pdf

[@wickedmessenger1]

My information was Type O = 350 PSI, Type K (lime & sand only) = 75 PSI, and NHL3.5=750 PSI. You do have the option of using NHL2.0 which is recommended for soft, chalky stone but I don't know its hardness -- probably the same as Type K. Here's a summary: "Masonry mortars are specified by ASTM C 270, Specification for Mortar for Unit Masonry. Mortars are evaluated by ASTM C 780, Preconstruction and Construction Evaluation for Mortars for Unit Masonry. Following ASTM standard the average required compressive strength of each mortar types is: Type M 2,500 psi Type S 1,800 psi Type N 750 psi Type O 350 psi There is also a type K-mortar but that is rarely used. That type of mortar is used for historic or ancient buildings that require a special mix. At very low compressive strengths, 75 psi only, type K mortar is normally one that you will rarely see and it is very difficult to manage due to its composition."

[@johnhendy1281]

Wow. That's interesting for sure. Yeah, I saw mention that NHL-2 was "like chalkboark chalk" which didn't incline me toward that. Maybe I'll do NHL-3.5 on the above-grade stuff I can see from the outside and consider hydrated lime + sand for the inside where I'm not as worried about weathering. Your results have me questioning that plan though. Sigh. So complicated!

[@dublinsnob3989]

Only time will tell I am starting pointing 1840s Sussex house survived the bliz bombing WII brickwork gable chinmey wall in loft attic area previous mortar is now powder dust using ready made lime putty cheers.

[@mick2spic]

What about 100 year old concrete block/ cinder block? It is made with some Portland, but no idea how much. Could Type N Mortar work to re-mortar?

[@wickedmessenger1]

My gut tells me you'll be fine with Type N for your vintage cinder block. You will probably get a feel for how hard the mortar is when you rake out the joints. If in doubt, you can always get it tested so you know the original mix.

[@mick2spic]

Thanks for your opinion, appreciate it.

[@amezcuaist]

I think the bricks need to be wetted first .Then why have a load of mortar on a plaster hawk .Use a smaller plastic thing with two tilted surfaces and a vertical piece. So 3 surfaces and a handle all in plastic . The vertical joints are filled with a small oblong trowel . Press the mortar against the end --vertical part to form a wedge then lift the wedge out on the end of the trowel and it`s ready to plug the vertical joint . The horizontal joints are best filled with the narrow pointing tool but when removing from the surface always slide it sideways. Pulling straight out will suck the mortar out of the joint again . That sliding action works best for placing lime plaster too . Yeh that hawk full of mortar would be a PITA.

[@peterfcoyle9127]

Would like to the composition of the failed lime mortar. Unusual that it crumbled like that in couple of years.

[@Under-dogGamer]

Here a tip mate do your perps first then bed joints brush down later 45 degre angle to knock the snots and nt rake out joint. slightly dryer muck.Good job mate.Good full joints well done.One thing whats the broken bond about not schooled in historic builds lol.Didi you lay them?

[@kierenboimufc5940]

Imran Ahmed beat the joints Bentley with a Victorian churn brush to compact the joint and clean off snots

[@cottawalla]

I'm wondering if the dry hydrated lime you used to make your putty was too old and had already substantially gone off (become plain old powdered limestone again).

[@wickedmessenger1]

Hydrated lime is essentially unreactive, I have come to find out. It is used as a workability agent in mortar but never actually sets. It will react only if pozzolans are present in the mix. These act as a catalyst and back in the day masons used to mix materials in with the lime and sand that contained pozzolans. That knowledge has been lost and people trying to rediscover lime mortar are trying to mix sand and lime together without this catalyzing agent. Now that some years have gone by since I did the repointing found in this video and it is failing rapidly. I no longer use type O mortar and only use NHL3.5. I recommend you do the same.

[@cottawalla]

@@wickedmessenger1Hydrated lime in dry form is calcium hydroxide but if it's old and has been exposed to the atmosphere it has probably reacted already and reverted to calcium carbonate, which is useless except as garden lime, or a plasticizer as you said. Where i am, the manufacturers specify their product as 95% calcium hydroxide after 3 months, and i assume that is provided the packaging is fully intact, but it's common for the double paper bags to have tears or holes from handling. I haven't tried using ity to make putty yet but i may do so just to see. Best to buy lime in the putty form already, which is the same stuff only with additional water added in production, and will last almost indefinitely if kept sealed. I've had mine for more than three or four years before I've used it and was very nicely matured by then. I haven't had the need yet to add a pozzolanic additive. I've got a bag of fly ash to try at some point when i do.

[@wickedmessenger1]

@@cottawalla I know that some of the lime specialty companies that make lime putty or who provide custom lime mortar mixes based on the existing mortar in a historic building actually make a product that sets like it should and will make lasting joints without any additives. I suspect that their lime source already contains catalyzers. However, I have been in correspondence with someone who actually talked with an engineer at a company that makes mass-produced hydrated bag lime and he told him that their product does not set. Period. It does not react through carbonation and it is solely a workability agent. People buy this and assume that this lime is like lime from the olden days and it is not. I was one of those people. At this point none of this is relevant to me because I'm totally sold on NHL and see no need to go back to hydrated lime putty to make mortar, even if it actually works, like that from specialty companies.

[@cottawalla]

@@wickedmessenger1 it would interesting to see the actual chemical breakdown of that bagged lime. The reason i bought the putty (a tonne all up on a palette) was because i didn't trust the dry bagged stuff, and i can't get NHL where i am, which is why i also have the fly ash to try. For me doing a DIY restoration, the non hydraulic putty is very useful. I can mix a batch of render or mortar, store it in pails under an inch of water and just use it as i need it. I can also work slower without getting into trouble.

[@frednowicki7355]

The lime mortar today is to pure. Meaning the old limes were either wood or coal fired. That method added a small amount of "contaminants" which provided a slight hydraulic set to the lime,increasing durability.Also,coupled up with unwashed sand,the sand had slight clay deposits which also acted in the same manner. Today,add between 20-40 % pozzolan in the form of a metakaolin and the the result will be much better. B.A.S.F. chemicals or Imerys market their Kaolins one is called Metastar.

[@wickedmessenger1]

Thanks for the information, which is entirely new to me. I appreciate your taking the time. Previously, I looked into NHL 2.0 and NHL 3.5 as a solution to this problem but found that the one most common for repointing, NHL 3.5, was much, much harder than the Type O mortar mix I ended up using and the NHL 2.0 is so soft I was afraid I would be right back in the same boat with it deteriorating to powder. I hate using Portland cement for this but I ended up selling myself on it as the solution because I did some work with this same mix on this house probably 15 years ago and it's still perfect and it's very soft so I feel like I am doing no irreparable harm. The high water table here makes for a perpetual case of rising damp in the brickwork and I don't know if NHL is resistant or not. I feel like the "self-healing" properties of lime putty mortar are important, especially with all the shaking from new construction around me. I regret that I may be giving up that feature with the 1:2:9 mix I am using. Do you know if this Metastar is resistant to rising damp and helps or at least does not impede self-healing?

[@frednowicki7355]

Also,in your search engine look these papers up. They will shed more light on the subject....lime metakoalin mortars,Why is type S special by Margret Thomson, Also patent search for Corson hydrator mentioned in Thomson's paper. The usage of Metastar will diminish the permeability of the lime mortar too the percentage added ,in the range of 20-40 % as I recommended. That sacrifice should not be an issue as the improved durability is well worth the trade off. Should you desire,send me an email at bricksrme@gmail .com and I will send you enough info. to read to keep you busy for a week. Those papers will dispel the myths emanating from the U.K., Scotland,France and the "boutique / charlatan " special lime purveyors in the United States.

[@johnhendy1281]

Learning about this myself for my limestone basement, and just wanted to comment on "NHL 3.5, was much, much harder than the Type O mortar mix I ended up using." Where did you find that? I've been perusing forums and someone linked to this: - www.limes.us/wp-content/uploads/2013/04/APTI-ComparativeLabEval.pdf That shows NHL-3.5 at 4.15, Type O at 8-9 (depending on lime) and Type N at 15-16 MPa, respectively. Seems like 3.5 is the least strong.

[@gregmorgan3308]

When you are adding 2 parts lime to your type O mix, what kind of lime are you using if not NHL 3.5?

[@wickedmessenger1]

@@gregmorgan3308 It was hydrated lime in bag form. It is not the same as NHL3.5 and I have come to believe that it is essentially unreactive and never really hardens. In this form it can be viewed only as a workability agent. Since making this video I have switched over to using mortar made only from NHL3.5 and sand. I no longer use white portland for anything.

[@redlady935]

Hi there, how old is 'historic buidling' Mine is 100 years old so am unsure if this counts as historic. Many thanks :-)

[@wickedmessenger1]

It doesn't mean anything specific, I suppose. In this context it means the bricks are held together with lime mortar and not portland cement mortar. Portland cement mortar was around for a long time but really started becoming mainstream in the years heading into WWII. After the war it became dominant with the building boom. In the United States, 80% of all existing buildings were built after WWII so that might be as good a dividing line between modern and historic as any.

[@sjh9173]

Anything 1939 or older would use this application. They used a heavier clay in the bricks in older homes.

[@christyb271]

I found this issue in my roof attic wall my chimney above. Age of my house is 1840s.

[@sjh9173]

I'd be very careful using Portland as it could cause the bricks to spall.

[@wickedmessenger1]

Read the comments in the description. I have totally disavowed the use of Type O mortar and now only use NHL3.5. Since I did this video the work has not held up very well and it is flaking off. My work with NHL has been very successful and I encourage you to watch my video of repointing with NHL3.5. There's a link in the description.

[@soundbwoikilla764]

I know this was posted a while ago, but to clarify - what kind of lime did you use in the original lime mortar that failed, did you use hydrated lime (e.g, type S) to make a putty to mix with sand? I see in your note that you've moved over to hydraulic (NHL 3.5) lime.

[@wickedmessenger1]

Yes, hydrated bag lime mixed with water and allowed to soak for several months to make lime putty. Miserable failure. It turns out that hydrated lime is strictly a workability agent and does not "go off" or, in other words, set the way we imagine that it does. Now that I have experience with NHL I will never try anything else.

[@soundbwoikilla764]

@@wickedmessenger1 There is a lot of bad advice out there that says you can use type s hydrated lime to make lime mortar. When I first researched lime for my old house repairs, the first red flag about type s is that none of the mfgrs say you can use it to make lime putty and all say it is for use as an additive to portland. A lime chemist later confirmed this to me. I too use NHL (the "real" lime putty is too expensive for me.

[@santrece1350]

What do you think will eventually happen since you've decided to use "portland" type O mortar?

[@wickedmessenger1]

See the video description. I have long since disavowed Type O mortar and now only use NHL 3.5. See my videos on NHL. As for what will "eventually" happen, it has already happened. The mortar failed, turned to sand. Bag lime does not harden. It is useless for that purpose. It is essentially NHL 0.0.

[@santrece1350]

@@wickedmessenger1 Yes, after writing what I wrote, I read what you wrote about disavowing type O.

[@oldmanfromscenetwentyfour8164]

Did you address the water issue going on outside? Poor drainage (downspouts not flowing away from foundation), possibly house is sitting on an aquifer, city water and sewer pipes leaking or cracked? Leaking roof. There are dozens of issues that might BE the problem. Simply repointing and not attacking the problem, you'll still have issues. PS: Type K mortar is 1-3-10 (sometimes 9), you went to 11, what binders you had in the mix were stretched too thin to do anything.

[@wickedmessenger1]

I did everything I can for what I can possibly influence. The main problem is that the water table is just a few feet below the foundation and it swells at high tide twice a day. During king tides the street floods. And this isn't going to get any better. Mean ocean level has increased by 1 foot in Charleston since 1900 and it's accelerating. Since making this video I have switched exclusively to NHL3.5 and it seems to be holding up much better. I will never use a mix with portland cement again.

[@oldmanfromscenetwentyfour8164]

@@wickedmessenger1 I understand and sympathize, having a historic Eastlake home with a natural stone and lime mortar foundation and yes, I live along the coastline as well. Stone, brick and mortar's natural "wicking" is the issue. Combine that with the water table variation and it's a disaster waiting to happen, like you said there's not much more you can do. I've dug trenches around mine for a french drain, all that did was give the water more room for growth. If I could buy and tear down my neighbors house I could have a natural duck pond by digging out a shallow. This is a common problem, more common that people are willing to admit. For that guy who said, "no such thing as rising damp.", Sit down and be quiet, you don't know what you're talking about. Drilling in the basement floor until you hit "dry land" and pouring concrete support pillars is about all you can do to keep the house from having further issues BUT that will cost more than the house is worth. It might be cheaper to move the house to higher elevation.

[@soldier-Dave]

wickedmessenger1 so it permeating damp then!

[@ajaxhacks]

Thanks for the video. You do great work. I'm working on restoring an old 1882 Victorian home in downtown Los Angeles area that is mostly original, including the lime plaster walls and lime masonry brick foundation. I've been trying to source "quicklime" here in LA and have been finding seasoned masons and historical experts confused on the use of Quicklime/Calcium Oxide and Type S Lime Hydrate/calcium hydroxide. It sounds like you used Type S Lime Hydrate on your original pointing job years ago. If so, putting the Lime Putty in buckets covered with water for a month is what you would do after "slaking" quicklime. Quicklime and Type S Lime are two completely different animals. Basically your buckets of Lime Putty where dead on arrival and still dead when you did your repointing. Instead of the lime mortar getting stronger with age from the CO2 in the air, the bond broke down from temperature, moisture, and vibration. Both Lime and Portland are "cements", however, if you don't use Lime in its Quicklime/Calcium Oxide state and slake/"boil" it to putty, it is not cement and is instead an adjunct to other cements like Portland Cement. So, if you use Type S Lime, it is dead, not a cement, and needs to be used with a cement like Portland cement to set up. Would be great if you could do a test after slaking quicklime and pointing

[@wickedmessenger1]

Since I did this video I have become sold on naturally hydraulic lime (NHL 3.5) for repointing. Please watch my video "How to repoint with NHL 3.5." It is also easier to use than quicklime and there is probably a local supplier if you're in a big city like LA. Here is a link: kzbin.info/www/bejne/d4Wog2qXf9OdeJI

[@StevenEElkins]

D Fitz Trans Mineral in Petaluma, is the sole importer of St. Astier NHL.

[@drfc94]

The joints need raking out 20mm or twice the width of the joint at least whichever is larger

[@GLYNDYER]

I can’t see how you can blame rising damp for the condition of the mortar. The bricks look as dry as a bone and rising damp does not exist anyway apparently.

[@wickedmessenger1]

You can't tell how damp these bricks are by how they look. They are indeed wet. There is a kind of backlash against rising damp coming from Great Britain where con men are swindling homeowners by blaming all manner of problems on rising damp and charging them for expensive damp-proof course treatments. Rising damp is not a problem for modern masonry because portland cement mortar and today's bricks are 30 times denser than historic bricks, such as the ones in my house. So in a way you're right, rising damp does not exist in modern masonry but you're wrong in saying it doesn't exist at all. Since I made this video almost 3 years ago the new repointing work has begun to slough off again and is well on its way to turning into what you see in the beginning of this video. Also since since making this video and the Part 2 video, I have sworn off using Type O mortar and now exclusively use NHL3.5 for my repointing. Any concerns I had with it deteriorating in rising damp situations are now assuaged. They videos on using Type O still are relevant in terms of technique and procedure. I recommend watching them but disregard the mortar mix advice. Click here to watch the video on repointing with NHL 3.5: kzbin.info/www/bejne/d4Wog2qXf9OdeJI

[@1988dgs]

Ahh, the capillary action deniers 🤪

[@soldier-Dave]

Rising damp..no such thing.lime putty...too soft when dry to be used to repoint later bricks that are denser and less breathable than old bricks....mixing cement with lime!?...oh dear. ....this mix will be flaking in a couple of years! looking forward to your next video...dealing with internal damp!

[@incith]

There's actually a comment from him saying this exact same thing...that it flaked off, he replied to someone else about it lol. Good call man!

[@MusicComposerZenki]

I guess that is why they mixed it with rice soup instead

[@MRBLACK33366]

4 sand 1 lime half cement. That's the ratio we use on historical walls that are open to the elements. I just repointed a 300 year old cooks garden wall on a stately manor in knaresbrough uk took 6 months😱. What you need to remember is that lime is used because it's softer than the brick so if you have a damp wall the water will release at the weakest points. If you put in a stronger mix it will still come out at the weakest point so basically it's always going to come out until you sort out the damp problem 1st. Unless u put in too strong a mix then the brick will fall apart

[@sjh9173]

... and cause spalling in the bricks

[@NUMENOREAN91]

Hot mix quicklime nigel copsy style

[@LiamGrubby]

Finally! Someone who understands traditional builds

[@markmaddison5312]

What a crock of shit you don't know what you're talking about

[@yourmaw6839]

Why did you put cement in it. Just 1 Sharpe 2 plastering sand 1 NHL 3.5 would've done it

[@wickedmessenger1]

If you look at the long discussion under the last comment by Konstantin Tantin below you'll see a lot of discussion of why I did what I did. But the short answer is NHL3.5 is drastically harder than Type O mortar, I had already been disappointed by deterioration of lime mortar from rising damp and I feared a repeat performance, and I have some history with using Type O mortar with the house with no adverse affects -- and I know it can stand up to rising damp. The purist in me does not like my decision but the practical side of me won out. I have some more repointing to do and I might try a little experiment with NHL3.5 to see how it works.

[@DRJMF1]

Listen all, hot lime is the best. Just add 1 part calcium oxide pellets to 2 parts sand aggregate and 1 part clean water and mix carefully in a tyre bucket using trowel wearing good ppe.The aggregate needs to be defined carefully however, less than 10mm and above 50 microns depending on width of joint. The material is filled into the joint as in the above video, left for a few hours to allow to partially set and then hammered using a hard plastic hammer and then churn brush hammered to expose the aggregate and get co2 into the joint. Keep water and direct sumLight off the joint. Except for st astier hydraulic lime, most manufactured lime products are of a poor quality. The manufacturers do not want you to know the above formulation I have just given you. The plasticity and mechanical strength and water sealant properties of the hot lime formulation are far far superior because it is the heat realeased whilst in the joint which facilitates the release of water to allow co2 in to make limestone. Ha ha ha ha. Just experiment with different aggregate particle size distributions to perfect the mortar. The calcium oxide is only 100 pounds per tonne, aggregate about 50 pounds per tonne. Compare those prices to expensive hydraulic limes......there's no competition. As always, putting power and performance into the common working man, out to get robbed by the manufacturers.

[@krakenhackenla]

Agreed. Not as easy to get hold of. I built a wall with hot lime mortar (3 sharp sand : 1 quicklime) different than cement mortar to use. Could have gone over the joints with a piece of wood to compact and fill any cracks that appear, then hit with a churn brush.

[@StevenEElkins]

DRJMF1 BINGO!

[@josephstankiewicz3338]

i don,t care about the outside house cover with alum siding i care for the inside this home is 116 yr old be dad loved drop ceiling with small cardboard tiles mom loved wall paper paper not all most sheets to me it all most like a table cover i just want great inside walls to live so u think i got lime just peel it tuff wallpaper and re lime the walls how can i tell

[@geo4415]

wow...a beautiful finish...and a excellent job over all.

[@platosocrates239]

Use hydraulic lime, NHL2.

[@wickedmessenger1]

It's a bit too soft for this application. I now use NHL3.5 exclusively for repointing work. Since making this video I am never using Type O mortar again.

[@santrece1350]

@@wickedmessenger1 A pozzolan should always be added to diy lime putty (for outside work). 10% of the mortar mix (max. amount).

[@szcze]

this video might be an explanation of what you experienced: kzbin.info/www/bejne/f2nUlpt4oq6glcU

[@wickedmessenger1]

Yes, that's certainly the same failure that I had (powdery, no strength) but I'm not sure how it could have happened to me unless the lime was set up already when I bought it. I bought the lime from the major supply house that everyone uses for historic work so I assume their inventory turns over rapidly. I used the lime immediately to make putty then let the putty sit under a few inches of water for an extended period of time. Also, I did this several times for different areas of the crawlspace on and off over the course of a few years. Everything failed the exact same way. I really think it must be the rising damp doing this. And if it is the case that the lime was already bad the day I bought it, my conclusion would be the same: I can't get by with just lime mortar and must use portland to make Type O mortar. I think that now that I know more, the next time I repoint the last few areas I still haven't done I'm going to try NHL 3.5 and see how that goes. I stayed away from it because it's so hard but I think an advantage is that it has better vapor permeability than portland cement and will help the rising damp evaporate through the mortar.

[@joshtargo6834]

what type of lime did you buy? How did you make your putty? We are doing an 1861 brick house now and want to make sure we can learn from your issue.

[@wickedmessenger1]

It was probably 10 years ago so all I know is that it was hydrated lime in bags, not the brand or any other details. What's typically available is Type S hydrated lime so it was probably that. I put water in 5 gallon pails and added the lime to it while mixing until it was fairly soupy. I topped it off with more water and let the pails sit for about a month. The lime settles so you just pour off the water, which is pretty clear and you have nice lime putty. I mixed with sand around 3:1 sand to putty and beat the mortar with the end of a 4x4 to really force the lime into the grain of the sand (something they used to be done back in the day for the best mortar) then went about repointing. I sprayed it down lightly for 3 days to make sure it stayed wet while setting up. The video shows what that got me: loose sand.

[@darllolohea2997]

wickedmessenger1 hydrated lime never cures. your supposed to use hydrolic lime.

[@darllolohea2997]

wickedmessenger1 that looks exactly like hydrated lime, it just turns to dust.

[@lifter98]

Doesn't look damp, and no such thing as rising damp. Maybe it dried out to quickly when you applied it. You need to keep spraying it with water over a few days as it starts to dry out

[@wickedmessenger1]

There is without a doubt such a thing as rising damp in porous brick with lime mortar. I am aware of the "debate" about it but I believe it's due to a lot of scam artists who con people in England that they need an expensive damp-proof barrier installed when they really don't need it. This has made people say it's always a scam and there's no such thing. Here in the United States, most people have never heard of it and most structures are immune to it due to the vast preponderance of existing buildings having been built from modern brick with portland cement mortar. In this case, with a 19th century building made of brick that drinks water like a sponge, a very high water table (sometimes actually coming up into the cellar through the ground), and salts from hurricane flooding now permanently in the brick to greatly worsen the rate of absorption of groundwater. Since I made this video 2 years ago I have disavowed the use of Type O mortar and now only use NHL 3.5. You should watch my video on NHL and ignore this video and part 2 of this video. Also, please stop telling people there's no such thing. It's a real problem in certain situations with certain types of construction.

[@electronurd3234]

​@@wickedmessenger1 ‘If you build a brick pillar and stand it in a tray of water, the bricks in the water will get wet, but the water doesn’t rise by capillary action,’ said Howell. ‘Cement-based and most lime-based mortars will not allow water to go through.’ Jeff Howell, a qualified bricklayer and author of The Rising Damp Myth (2008) said trials in the laboratory confirm the falsehood. "Rising damp" is a term that should not be used lightly. What we are slowly discovering here in the UK is that "rising damp" has been abused to trick people into believing they need to stop it by injecting bricks with glue/resin. Rising damp is usually the result of some sort of 'failure' structurally, incorrect methods of "curing" a problem or a cracked drain pipe. If you go to Holland where homes are pretty much built on top of marsh/fen land they have no idea what rising damp is. Another small good read. www.woodwardsurveyors.co.uk/blog/does-rising-damp-exist.html So..Eric is ok to say it's a myth of there is no scientific proof to suggest it is actually true. The truth is that there is not enough research out there at the moment as no funding would be given to such extensive research as too much money is being made from the "myth"... even the banks are in on it... they refuse to give mortgages in the UK to people unless they pay to have an "injected dpc" installed. Can you imagine if rising damp was proven to be a solid myth?? people would be owed large sums of money in compensation for paying to have work done that was not necessary. I like your video though and thank you for using lime instead of cement.

[@wickedmessenger1]

@@electronurd3234 This excerpt you have posted says what I said, which is that modern materials do not conduct rising damp but porous brick and lime mortar do conduct water through capillary action. It's not something most people will encounter because most structures are not old enough. But those that have the right kind of brick and mortar plus a high water table do experience rising damp.

[@patrickjoyce6302]

Lime mortar don't have cement in it correct mix5 sand X1 lime

[@StevenEElkins]

Patrick Joyce that would’ve lasted six months instead of two years.

[@bojo6721]

What a xxx, xx mess,,,.

[@livelearn664]

Mix is too wet....