Limelight on New York City

New York City surpassed Philadelphia in 1790 as the largest city in the United States. Throughout the 19th and 20th centuries immigration and modern developments changed many facets of the people, transportation and infrastructure. But what still remains in the city that never sleeps are gorgeous relics of the past, being preserved for generations to come. A team from LimeWorks.us recently visited the Big Apple to take look at a few places which have been repaired in-kind with historically appropriate materials.

The New York Life Building was completed in 1928 at a cost of $21 Million. It’s currently undergoing a repair campaign using Lithomex for stone repairs and patchwork.

The Irish Hunger Memorial stands as a tribute and reminder of the Great Irish Famine and the tragedy of world hunger. Stones were donated from each county of Ireland and even an entire cottage was transported and reassembled on site at Battery Park in Manhattan. Historically accurate lime mortar was used in the construction of this memorial which ensures that it will remain standing tall.

The Eldridge Street Synagogue is an incredibly gorgeous testament to the architecture and influence that once spanned across the Lower East Side from the Eastern European Jewish community. This was the first Synagogue constructed by the Eastern European Jews emigrating from Russian, Romania, and Poland. It was built in the late 1800s and flourished into the mid 20th Century. As the neighborhood changed and new immigrants arrived, membership dropped and the synagogue was left virtually abandoned through the rest of the 20th Century. The rescue effort of the Eldridge Street Synagogue began in the late 70s when volunteers and the Friends of the Eldridge Street Synagogue initiated efforts that led to an $18.5 million dollar repair campaign. This campaign included repointing work of the facade using historically accurate Natural Hydraulic Lime Mortar from LimeWorks.us Additional repairs to the ceiling, wallpaper, paint and almost every aspect of the central room was restored returning it to its original glory. The final element was set during the fall of 2010, the stained-glass window commissioned by Kiki Smith and Deborah Gans is the only 21st century element inside the historic space.

More details of the Eldridge Street Synagogue restoration can be found in the latest issue ofTraditional Building Magazine

We also visited the Cathedral of Saint John the Divine and the Ephesus Seventh Day Adventist Church in Harlem. Both have used in-kind repair materials from LimeWorks.us. By using breathable masonry repair materials, all of these historic structures will surely stand as testaments to the rich history of the Big Apple for generations to come.

-LimeWorks.us (Linked-in : Blog : Facebook : Twitter)

All Photos Copyright: Sean K Maxwell

Historic Fabric melded with Traditional Mortar at the Irish Hunger Memorial in New York City

Blocks from the World Trade Center Memorial and the construction site of the new World Trade Center sits a half acre patch grass dedicated to raising awareness of the Great Irish Famine. This memorial was under construction on September 11, 2011 when the Twin Towers fell. The memorial saved that day, simply because of the direction the wind was blowing. The plume of dust blew from 1 World Trade Center in just a way that it didn’t touch a single stone, all of which were donated from each county throughout Ireland. Even a 19th century cottage was disassembled in the County of Mayo and re-laid in Manhattan using a lime mortar that was determined to most closely match that of the original. The memorial was dedicated in 2002 by former New York mayor Ed Koch.

A team from LimeWorks.us recently visited the site and put together a collection of images seen below. The names carved in the stones represent the counties of Ireland. St. Astier Natural Hydraulic Lime was used throughout the memorial walls and cottage, supplied by LimeWorks.us. The structure has been holding up very well and we are very proud to have been part of this important piece of built heritage.

-LimeWorks.us (Linked-in : Blog : Facebook : Twitter)

All photos Copyright Sean K Maxwell

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Lime Paint and Plastering System for Interior Application, FAQ Friday

Building on last week’s FAQ Friday, the use of lime paints doesn’t have to stop with use on the exterior of a building. Lime paints are great for use on interior walls by themselves or used as a pre-hydrated and dispersed pigmenting agent that can be mixed with Ecologic^® Mortar, NHL or a combination of the two when formulating your own colored plasters.

There are many benefits of using lime paint on internal walls but there sometimes needs to be some preparation involved to make sure that the lime paint or plaster will adhere to the substrate. Often times I hear that someone will want a colored plaster finish on their interior walls but they do not know if lime paint will adhere. The simplest way to check is to spritz some water on the wall. If there is no absorption of the water, the wall is either too smooth or not porous enough. We need some suction. One way to achieve this is to apply a base coat of Takcoat™.

Takcoat™.  was discussed in detail in a previous FAQ Friday. So to keep it short I will just say that it is a VOC free, transitional lime and sand prepared plaster material that can be applied to smooth painted or unpainted surfaces. Once Takcoat™. is cured then adequate suction and mechanical key is provided for Lime Paint and lime plaster to adhere to the wall surface. There are ranges of different lime finishes that can be applied to the wall ranging from a rough open pore surface texture to an incredibly smooth polished Venetian or Tadelakt finishing style. The finish is dependent on the client’s wishes and the skill level of the craftsperson.

In my opinion, craft skill level is fundamentally dependent on the tools a craftsperson has at their disposal. One important tool to have when formulating different plasters is pigmentation. The lime paints we sell at LimeWorks.us come in a variety of colors that can be used as integral pigments mixed into plaster formulations or on their own as a decorating top coat. Having a good pigmentation methodology gives a craftsperson more options during the planning stages of a project. A good pigmentation methodology also makes reproduction of the mockups on to the entire application easier once a decision has been made on a certain color since the consistency of our products makes this a smooth process.

Lime paint comes as a dry powder consisting of a high calcium lime paint base and dispersed pigments if the paint is a colored one. Dilution of the lime paint with water to make a quart, gallon or 5-gallon unit will further breakdown the pigment and further slake the hi-cal lime. When a known volume of paint has been made it can be used in Ecologic^® Mortar formulations or gauged into lime plaster for color. Here are a few examples…

Sample 1- lime paint lp-347 over Takcoat™

Sample 2- 1/2 bag NHL 2, 4.3 gallons LP-347, 1.09 gallons water over Takcoat™

Sample 3- one bag Ecologic® Mortar Fine with 1gallon LP-347 over Takcoat™

Sample 4- one bag Ecologic® Mortar with 1quart LP-347 over Takcoat™

When a specific color is desired but not represented by our stock lime paint color options then we can provide custom colored blends for all sorts of various applications. Seen in the photos below Thuillier Plastering of New Hampshire used a custom Ecologic^® Mortar Fine that incorporated additional NHL 2 and pigments to achieve a Tadelakt finish. The authentic formulation was then polished with rubbing stones and the olive oil soap we sell, following an ancient Moroccan tradition.

So whether you know what style of plaster finish you want to achieve or you would rather let your imagination run wild and experiment, just contact us and we will be able to help you develop your plaster system to ensure a successful project.

-LimeWorks.us (Linked-in : Blog : Facebook : Twitter)

How Lime Mortar Traditionally Got Its Color and How We Can Replicate This Today, FAQ Friday with Randy Ruth

Seven factors that can affect the color of lime mortar in no particular order of significance, Lime, aggregate, pigment, water content, rate of absorption, original surface texture and erosion.

By its self, the color spectrum of lime can vary from bright white, light grey, slight pink or ochre colors. This color is dependent on a few factors such as the original stones chemical makeup and burning temperature. When an appropriate limestone is thoroughly burned (calcined) at a particular temperature to produce hydraulic or non-hydraulic quicklime and then hydrated to produce either a lime putty or dry lime hydrate, the result will be a white or off-white color. The first factor affecting the whiteness index of the lime will vary depending on the raw mineral impurities in the limestone. A limestone with a higher calcium content with all other factors aside will produce a whiter hydrated lime. If that same limestone is burned at a slightly higher temperature, the result will be a slightly grayer hydrated lime. Although, lime plays a role in the final color of a mortar, its significance today, when replicating a mortar joint is minimal, often due to the lack of availability or technical characteristics like Hydraulicity.

Aggregate has a huge effect on the color of lime mortar. Historically aggregate for masonry mortar would be sourced from either local sand beds, found near creeks or rivers, or from the trimmings of stone on site and possibly brick pieces or dust as a pozzolanic additive. The larger screenings of the aggregate play a role in the overall tone of the final mortar color but it is the fines that do most of the work. The smallest particles in the aggregate AKA fines will give the biggest impact on the final color. Brick dust, limekiln dust and clay impurities are pozzolanic fines that can be found accidentally and at times intentionally accompanying the aggregate. Today these impurities are almost never allowed into a replicate mortar mix, as the resulting technical data from such a mix design is often cost/time prohibitive for a project even if historically appropriate. As a result powdered pigments are often used today to achieve a particular mortar color.

Just because pigments are predominantly used today in mortar mix designs, doesn’t mean that they weren’t used over 100 years ago. Colored mortar is an important design element in any building of today and yesteryear. The types of pigments used in mortars have not changed all that much in past few hundred years. Iron oxide, carbon black, and natural ochre’s hold a solid footing in the industry today, each presenting their own limitations.

It has been proven that carbon blacks can fade dramatically over a 30 year period in masonry mortar. Even though their tinting strength is very good, if not controlled carefully  shades of grey can be very difficult to achieve. Natural ochre’s can produce wonderful colors and be very accurate when making accurate replicate mortars. The problem is in their tinting strength, and consistency in production on a large-scale. It may take above a 10% dosage of natural pigment to achieve the same color in a mortar using iron oxide pigments conforming to ASTM C979. Because of their durability, tinting strength and quality in production, iron oxides have been deemed the best pigment for coloring mortar on a large-scale.

Even when using appropriate pigments at the correct concentration, water content in a mortar plays a big role in determining final color. Using the same exact mix in two batches and varying the water content by 10% will produce a significant change in color. From experience, I have noted that this problem is most evident when trying to achieve a red colored mortar. Light grey’s can also be problematic but are less evident and are usually deemed acceptable. That is why it important to measure all ingredients in a mix carefully to ensure consistency from batch to batch.

The practice of mixing mortars consistently should carry over to pre-dampening of masonry units. By pre-dampening consistently as possible, the rate of absorption is controlled. This is a good practice just so mortar will not reach a flash set, and to control curing of the mortar which plays a role in the final color.

There is some debate on how a replicated mortar should look when not replacing all the mortar. Should it look new, with a smooth surface that stands out because of the way light reflects off two different surface textures? Alternatively, should it blend in with adjacent mortar joints? Personality, I believe in the latter. If a new mortar is inherently the same color at its core as the old historic mortar, than even though a slicked smooth replacement mortar will eventually blend in it can still distract the eye. A good repair for just about anything should be as seamless as possible. Besides, won’t a different texture erode differently, resulting in the continuation of a miss match over time?

This brings me to erosion in mortar. As a mortar erodes, the color of the aggregate begins to come through. This color can sometimes throw off the human eyes perception of what is the color to be achieved when color matching. Someone explained this to me so well once that I must share. He had asked a room full of people what the color of foam on the head of a beer is. All replied white in color. We all got it wrong. The answer is amber like the color of the beer. This is because of the way light is reflected back to the human eye off a larger Surface area. Now that is in extreme case of a dark color turning lighter but the principle is still applicable to mortar. However, in most cases the rougher the color the darker a mortar is, and depending on who well the color of the sand is matched, you may just get a replacement mortar that will be seamless for generations.

-LimeWorks.us (Linked-in : Blog : Facebook : Twitter)

Andy’s Podcast Interview with the National Center for Preservation Technology & Training on the Role of Lime and its Continued Importance Today

Andy deGruchy of LimeWorks.us spoke with Jeff Guin the National Center for Preservation Technology & Training recently on the role of lime in historic architecture and in preservation, as well as in new green construction. Andy has over 30 years of masonry experience working with historic structures throughout the United States and abroad. He has been published in magazines and books sharing his knowledge of the historic application and current techniques for the use of lime mortars, plasters and paints.

Download this episode as an mp3 or Subscribe via iTunes 

Transcript:

Jeff Guin: Tell me about a few of the structures that you have worked on.

Andy deGruchy

A. DeGruchy: We’ve worked here in Pennsylvania with my other company, DeGruchy Masonry & Restoration, for the last 27 years we’ve been restoring brick and stone buildings.  Some of those have included work at Hope Lodge, Daniel Boone’s Homestead,William Penn’s Homestead,  James Hobin’s (architect of the White House) memorial in Mt. Olivet Cemetery in Washington DC. Also, a myriad of historic Victorian homes, farmhouses in Bucks County, Pennsylvania, where I live and all sorts of accoutrements, smokehouses, and summer kitchens and basements–some not-so-glorious buildings, but just a lot of hard work in the maintenance using appropriate materials to fix these vintage structures.

JG: So do you primarily work in the Pennsylvania area and the northeast or do you travel to other parts of the country as well?

AD:  Well we’ve concentrated our work within about an hour and a half driving radius of where I live and where my shop is in Quakertown, Pennsylvania.  However, we’ve done work as far as Florida and consulting work on the use of our materials as far as Puerto Rico and Maine out to Oregon and all over.

JG: …and to Nashville, I know, because that’s where I met you originally at the NCPTT Nationwide Cemetery Summit.  Are cemeteries something you work on frequently?

AD: We do not do a lot of cemetery work ourselves, although I did mention I restored the architect to the White Houses’ James Hobin and his memorial  in Mt. Olivet Cemetery, and dotted throughout our history, there has been some work on statuary and memorials.  But my connection with cemeteries has been at the prompting of a conservator and professor at Columbia who saw our laboratory and the work we are doing and said, “you know, you are the best kept secret, you really need to step up to the plate and tell the world that you are here,” and that is why we are even doing the radio interview now trying to get the word out that we have some great resources.

Understanding Lime Terminology

JG: Taking that a step further, there is a lot of confusion around the terminology related to lime mortars and specifications.  I wonder if you could break some of that down for me. Talk about the different types of lime and the differences between historically accurate lime as compared to the improved or modern types.

AD: Yes, that’s a very good question, and it is a little bit of a peeve with me because, you know, really lime is lime is lime and has been the same raw material from the beginning of time until now.  Nothing has changed, but a lot of smoke and mirrors and confusion puts the end-user, building owners, architects, engineers, and masons in a state of confusion. Really, it is a very simple thing to understand:  That is, lime has always fallen into two categories; it’s always been pure high calcium, 98% pure lime.  When I say lime, I do mean the shells and bones of marine life that build up over millions of years without any impurities in it.  If it was 98% pure, just comprised of that, then that is called high-calcium lime and then it falls into the second category, which is impure lime.  Now we designate that into a breakdown of two areas.  One would be dolomitic, which would have a smaller percentage of magnesium and then a magnesium lime which has a larger percentage of magnesium.

We look at ancient structures throughout the world, a lot of materials scientists will study them and say, “let’s not look at what is broken about this building, let’s look at what’s working so well that it is still here after 500 years.”  They will find common denominators. And with the mortar, they find that the basic rule in masonry is, you never can fight water and win.  Water will always win in the end.  So, the mortars in these ancient buildings had a lime and sand composition that would help to process moisture out to the atmosphere again.  It would not trap moisture.  Had it trapped moisture, or reacted with sulphates and other negative reactions, then the demise of the structure would have been accelerated, and it would not be here 500 years later.  But they found that when you use a lime that is a catalyst of processing water back to the atmosphere, now you have a symbiotic relationship with nature and with water.  Therefore, you are now not in conflict with nature, but you are going to survive because you found a way to get along.  The way that it does get along is that when the limestone, which could be a block of this sediment that I mentioned, is burned, it is the one stone that when you cook it for 48 hours, maintained at between 1,650 to 2,000 degrees, you will push-off the carbon dioxide content in the stone. In doing that, after the stone has cooled, it weighs 44% lighter than it did when it went into the kiln. When you reintroduce water to it, it will violently take that water in what’s called slaking–like slake your thirst–and it will boil the water it sits in within a 10 minute period.  However, a little known fact is that if you look at that same mortar now that has been made with that lime putty and sand has been added to this putty that has had the water reintroduced to the limestone, you can go with a future 10 years, 20 years and 30 years and the lime is always slowly converting back into a limestone again through carbonation. It violently draws carbon dioxide out of the slaking bath at first, and it is a young buck at that time. But 5 years later, 10 years later, 50 years later, it is still trying to convert back into a limestone and will always draw carbon dioxide out of the air. So that is the symbiotic relationship again with nature. When all these nor’easters and wind and water blow on buildings, they are delivering carbon dioxide and the lime mortar joints are hydrophilic. So these walls that get saturated actually give up their water towards the attracting lime mortar which then says, “can we have that carbon dioxide from you because we are still converting back into a stone” and then releases the rest of the vapor out to the atmosphere. So this dynamic that has been going on, which material scientists have come to understand, is something that has preserved historic fabric. Because no longer does the soft sandstones and bricks that had they had the wetting and drying cycles go through there, faces would have exfoliated and been damaged. Now the historic bricks and stones give up their moisture to the hydrophilic in attracting lime mortar.

When the Romans who were famous as architects and builders, they burned lime at this time-honored temperature to maintain the reactivity of the lime between 1,650 and 2,000 degrees, it had the ability to convert back into a limestone. However, today’s modern production dead burns lime and in many cases and over-cooks it. When you say to the lime that you can get it at any hardware store available in the country today, and say well, I’m going to add water and sand to you, I’d like you to convert back into a limestone and become as hard as hopefully you were at one time as a stone: that inert dust can only be used for adding plasticity, a flow-ability to a cement mortar or controlling the setting time of a cement mortar.  The majority of the available hydrated dolomitic Type S hydrated lime in the United States has just sand and water added to it as a stand-alone binder. It does not have the ability become as significant and durable as the historic mortars because of the burning temperature.  So the problem–although there is only two kinds of lime in the world and always has been–the way the lime is cooked has been changed in that it is being sped up for the process of production because the key elements it’s only asked to do today is that plasticity and control of setting time of a cementitious mortar.  We have personally not had any success with using a Type S hydrated lime and adding sand and water and then putting it into service as an exterior above grade mortar in extreme free stall cycles like the northeast, mid-Atlantic states where I am from.

The limes to reproduce historic mortar when we work at some local building, someone might say, “Are you going to go build a kiln and find local lime and reproduce every element as it originally was?”  Well, the cost becomes a problem, so we import the natural occurring hydraulic lime, which is pure high calcium and evenly dispersed silica so that we know when we add certain percentages of sand, we are going to get a final result that is going to have a known value for liquid and vapor permeability, PSI strengths … So it is true that in the United States and Pennsylvania, maybe these historic structures were not built with French hydraulic lime but it is a suitable replacement that pound for pound and cost-wise, is reasonable and we are putting in an in-kind replacement that will do no harm.

New Uses for Lime

JG: Do you see lime being used just in historic applications or are there new applications for lime now?

AD: We have a 100,000 bag order for a tropical resort that we are creating a lime for a green build.  Because, as I mentioned, the mortars that we have used for historic restoration, our intent was only to use them to do an in-kind replacement like-to-like–instituting no material that was going to cause an associated damage to historic fabrics surrounding the stone or brick, you know, like the window frame or something expanding and damaging because of what we used.  However, as I mentioned about people from the cemetery, conservators and fine arts finishing people–we’ve also found that it really meets the criteria for gold and platinum LEED credits. When you are trying to lower the embodied energy, the building of what has been used by reclaiming and recycling, you know, existing post consumer material and getting all sorts of energy advantages in improving indoor air quality, they find that the lime just to begin with–because there is 7,500 years of building history proving that it works, where modern cements although introduced in the 1870’s in the United States, in my opinion did not fully take hold until after WWII.  So the window of time where cement absolutely dominated for all veneer mortars and building and stucco and everything, came like 1945 until now.  But the embodied energy to create a pound of Portland cement, which is the binder for modern stuccos and brick laying mortar and stoneware is incredibly high.  Matter-of-fact, I believe the efficiency is very low because there is more waste than there is usable product.

Making Lime Repairs

JG: Now lime mortar does have to be re-applied occasionally because it does work with the environment.  How often does that have to be done?

AD: Well there are many historic structures that are in the United States that are only just receiving their first re-pointing.  So, in the Philadelphia region, the area where I am from, we will see a historic building that you know, maybe was re-pointed in the name of preservation and maybe under the guidance of some government agencies and done only in the 1980’s, and yet it has to be re-re-pointed and it had a Type O or high lime content mortar with a little Portland cement added.  Yet, the 200 year old buildings in this region (down the street from the one fixed in the name of preservation) we will find that sometimes these buildings are actually in better repair.  What my goal was originally was to import lime from France and do the things that we were doing was kind of pursuing excellence and saying you know, if there is the concept of getting a 100-year fix because we see that these buildings are 100 – 200 years old and no one’ s re-pointing them.  They did not have the budget to fix it and it is in better shape than the one they did have the budget to fix. Maybe we should try to mirror the properties of the original material.  So, I would say that if a lime application is done appropriately, there is no reason–just like you see in Europe, old plaster over stone, brick and stone buildings or pointed buildings and no one is touching them for 100 years–there is no reason why you won’t get a 100 year life cycle if the project is done correctly.

JG: Is using lime mortars and re-pointing something that everyday people can do or is it just something for the experts?

AD: It’s all dependent upon the skill level of the individual.  So, we’ve met homeowners who do better work than some masons that we know and then we know young masons that their skill level just comes right out.  So what it comes down to, just what pointing is. It is not rocket science.  It’s just binder and aggregate.  It’s sand and lime and then it’s just placing that between bricks and stones but as you know and many who have observed historic buildings throughout the country, they will see blaring examples of bright white mortar that did not match the texture, the tooling, the color of the surrounding area and you have to wonder what were they thinking when they did that pointing job or built that wall like that and to this day, I still do not know what they are thinking but it is everywhere.  So, I think it boils down to not that it is so hard to do, but is someone willing to take the time and care for the project. That being said, some of our best customers, the ones who we love to work with, who are just savvy homeowners who have done their own research, they concluded what they wanted, how to do it, they will take a class and then they will take the time if they are going to do point the whole home, they will commit themselves to: “I’m going to do maybe one square foot but I’m going to do it right.”

Ian Cramb

JG: Tell me about Ian Cramb.

AD: Ian Cramb is a great man, 83-year old Scottish stone mason who lives in Bangor, Pennsylvania. He and his family have been steeped in stone masonry since 1750 in Edinburgh, Scotland and along the way. I think the common denominator of all these craftsman and artisans is love for the trade, and that caused him to assemble a book back in 1992 called The Art Of The Stone Mason.What made it very popular was in it, you could see the love he had for the trade and just carefully sketching out details describing how to cut a stone or how to build a stone arch or naming parts of a wall. All these things were very popular with masons because it was a throwback to how masonry had historically been done and those details again that is a common denominator that is going to make the outcome of any project become excellent and last for the 100-year fix.  So, he began to develop a following of people in stone masonry and I being one of them, bought his book years ago and then of course he is local and I touched base with him about some things and became friends with him.  Next thing you know, he had to get all the information together for his second book, which is The Stone Mason’s Gospel According to Ian Cramb.  As we drove along one day while on some projects we were building, he said, “You know, I can’t finish my second book and it’s all your fault,” and I said, “Well what you mean by that,” and he said, “You know, in all the conversations we have regarding the lime, you really have a better handle on the technical aspects and how to explain it than I do and I want to put that in this book.”  So he asked me to edit and read through his book and understand what he is writing, then put some information that is going to clarify lime.  So I helped him produce this second book with my computer science major son who is in college, to produce the book on the internet and we produced a few hundred copies and we have them now actually on our website for sale and that is The Stone Mason’s Gospel According to Ian Cramb.

Sharing the Knowledge

JG: So you kind of see it as part of your job, your responsibility, to pass the knowledge along; to make sure that people understand not just why it’s important but what the history of lime mortars is.

AD: Yes, very much so.  I think that there was a time when masons would of course hide the trade secrets.  They had their mason marks and they would mark the stones that they produced and shaped and dressed and they got paid piecemeal that way and some of the ancient trade secrets that sort of trail off into the Masonic tradition of the non-operating masons.  In today’s masonry, as we know, all our buildings are accelerating in degradation and as the buildings are getting older and older and fewer and fewer people are going into the trade, it has been my position to say there is no more time for trade secrets.  If anybody wants to know a trade secret we are glad to share it because it just does not seem like anything that resembles close to actually doing physical hard work, is not getting much of an audience of young people wanting to get into it.  However, those who do get into it, find it incredibly rewarding and then ask themselves, what was I thinking, I was going to go to college and I was going to be stuck in a cubicle somewhere, so  I am very much in favor of disseminating knowledge, giving it away, but I see a lot of exploitation of historic resources for the sake of personal gain by keeping a patient sick and not getting in there and putting in a repair that would give a long service life, and so I am totally opposed to that and I want to blow the blinders off of that thing and I want to shed as much light on these subjects so that we can move on with the good and excellent conservation of our nation’s historic resources.

JG: Andy thanks so much for being on the podcast.

AD: I’m glad you could include me and hope that it was informative.

-LimeWorks.us (Linked-in : Blog : Facebook : Twitter)

NCPTT original post

FAQ Friday, with Randy Ruth

This is the first in a series of blog entries that will feature mason, Randy Ruth. Randy is the lab technician at LimeWorks and receives lots of questions on masonry and the use of our materials. We will feature some of these questions each Friday in our FAQ Friday blog entry. First question…

• Q: I have an old stone basement foundation (house was built in 1900) and need to “re-point” or fill in holes in the basement walls.  Would your Ecologic mortar work? I am not sure that lime based mortar was used originally; would this still be OK or how can I tell if lime was used?
• A: “cement” was not produced in the united states until 1870 in Coplay, PA, only up until around 1910 was Portland cement starting to find its place in society as a masonry binder. Prior to 1910, most mortars used were based on either lime putty, Natural hydraulic quicklime or natural cement. Regardless of what the exact mix design was used to build your basement foundation, Ecologic® Mortar would most likely be suitable for repointing your old stone basement foundation walls as it would be sympathetic to the adjacent mortar mix by maintaining good vapor permeability. An easy way to determine if you have a lime based mortar, especially in stone construction, is to break a piece from the wall in visually inspect for any white nodules or specks. The white nodules are an indicator of what is called a “hot lime” mix and commonly found in stonework . Any presence of those nodules or specks suggests a high lime content mortar, and should thus be repaired with a comparable material.

Natural Hydraulic Lime – Creates Old-World finish That is a Perfect Finish Selection for Wood-Fired Ovens, Foundations, and Other Masonry Projects (via The Arch Blog)

Great post about a unique way to use Ecologic® Mortar.

The ARCH, known in part for it’s natural finish options, has recently gained more experience with a Natural Hydraulic Lime finish product that we offer.  Jim Erskine’s masonry experience spans thirty plus years, and as with most masons, his experience … Read More

via The Arch Blog