The Lime Green Plaster Blog » Tools and Techniques

Pozzolanic Hydraulic Lime

Authenticlime — Fri, 02 Apr 2010 23:40:18 +0000

A type of lime that has been used in construction since ancient Roman times is now covered by an ASTM International standard. ASTM International Committee C07 on Lime has approved ASTM C1707, Specification for Pozzolanic Hydraulic Lime for Structural Purposes. The new standard is under the jurisdiction of Subcommittee C07.02 on Specifications and Guidelines.

Read more here ASTM International Standards

Greening of Mortars with Pozzolans

Quote from ASTM.org

“Growing interest in sustainable building has created a strong interest in fly ash and other coal combustion products (CCPs). Emergence of agencies like the U.S. Green Building Council (USGBC) and the Coal Combustion Products Partnership (C2P2) of the USEPA has accelerated this trend. Their primary goal is sustainable development, focusing on environmental and social concerns. More than 30% of the 100 million tons of coal combustion products produced in the U.S. annually are being beneficially used in such things as manufactured stone, ceramic tile, shingles, concrete, aerated cellular concrete blocks, concrete blocks, stuccos, and mortars. The use of CCPs positively impacts the environment. Specifiers, contractors, and industry need to recognize that environmental stewardship today affects our children tomorrow. The features and benefits recognized in pozzolanic mortars reach beyond the technical, environmental, social, and sustainable aspects of this mortar. They signal future generations to track, improve, and develop mortars beyond any of our current technology”

Natural Hydraulic Lime (NHL) is seeing a worldwide comeback

Hydraulicity & Properties

Hydraulicity is the property of a binder to harden in contact with water.

Hydraulicity is produced by burning a limestone containing silica, alumina and iron oxides which above certain temperatures combine, totally or partially, with the Calcium Oxide. The resulting silicates, aluminates and ferrites give hydraulic properties to the product. Today as in the past, natural building limes are obtained by burning and slaking limestone and the more or less hydraulic character of the finished product is directly related to the percentage of calcium silicates, aluminates and ferrites formed during burning. The composition of the Earth crust shows the predominance of silica and its presence is almost inevitable in all limestone deposits.

Read the rest of the article here ST. Astier Lime mortars

Cement Stucco’s are Evil !

There I said it….but until the majority of home buyers and builders realize the benefits of hydraulic lime base coats and finishes we will be stuck with cement and acrylic stucco in North America…where time is money friends!

Evidence shows that lime has always been and will remain a practical, sustainable, healthier and greener alternative to cement, worthy of far more widespread use across the building industry.

Until the time the consumers realize these benefits, the ST. Astier NHL will remain relatively expensive,and cement will continue to be used as base coats for exterior stucco’s,which is a shame

Authentic Plaster FX from Vancouver BC. is working hard, exposing local builders to Natural hydraulic lime stucco’s, and venetian plaster finish coats such as Intonachino and Tadelakt. Discerning homeowners, architects and the exterior envelope engineers will look closely at the beauty and functionality of Hydraulic Lime plaster exteriors.

Limestone Plaster Arch

Authenticlime — Fri, 02 Apr 2010 23:40:18 +0000

We can create the durability and look of cut limestone with substantial weight and cost savings. Utilizing a proprietary decorative crushed limestone plaster. The limestone coating can be placed on vertical or horizontal surfaces in-situ, and finished to your specifications by our trained plaster artisans. We have full control over color, texture, finish (distressed, polished, honed, sandstone,tumbled, travertine effects etc.) to any customers specifications, creating virtually any architectural elements desired

The mixture is sprayed or troweled over any type of interior and exterior substrates (i.e., drywall, brick, tile, concrete, brown coat, foam) We then work the stone plaster by hand to achieve the desired pattern and texture.

Here’s the final look, completely done by hand, 2 days from conception to completion.

This particular project we were asked to create a tumbled and aged limestone effect, here’s a sampling of some of the processes involved ,the final outcome is completely in the hands of the skilled artisan plasterer.

First we confirmed the profile required with the Architect and designers , and constructed a template to suit there needs. The template is mounted to the horse and we then proceeded with the layout and finally the formation of the arch molding itself.

A snippet of lime plaster History:
Since Roman times, lime putty mortars and plasters have been used widely for internal ( today, venetian plaster and marmorino’s are still being made from this same lime putty )and external plastering and stonework. For external rendering and stucco, greater compressive and tensile strengths were achieved by adding various forms of pozzolans to lime based mortars.. burnt clay, volcanic ash, ( tuff ) brick dust, all such additives react with lime putty’s to form cementitous “mortars”

Limestone containing clay were also burnt to produce hydraulic limes (NHL) these set by reaction with water and by carbonisation of the lime.

Hydraulic Limestone Veneers

Using hydraulic lime in the above project we saved the owners time, which equates to money

Using hydraulic lime in the above project we saved the owners time, which equates to money …and we all like saving money …right?

Producing details in-situ such as the archway described on this Vancouver plaster project… is versatile, adaptable and flexible! Giving the Architect,the Designer and the homeowner design freedom,with both color and texture, with large pieces or building facades there is a further cost savings on engineering and construction costs associated with weight.

Compare this to having the architectural detail cast in cement or concrete,making molds, trucking and other logistics…or having the detail carved,which is the smarter alternative? Id say hiring a knowledgeable plaster and stucco contractor is the right move.

Tadelakt ….the “Red City”

Authenticlime — Fri, 02 Apr 2010 23:40:14 +0000

A fellow Tadelakt lover recently wrote to me with some of her experiences during a visit to Marrakesh,where she participated in real world application of true Moroccan Tadelakt….here is an excerpt from that email.

“What I really loved about Marrakech is that Tadelakt is everywhere in the red city, indeed I would say it is the red city because of the Tadelakt and all the beautiful pigment you can mix into it. In some of the very old palaces (Bahia and others) you can still see Tadelakt on the walkways and in the pools hundreds of years after, so it clearly withstood the test of time. Maalem Majid said that they add marble powder to the mix for the swimming pools. He even worked on the villa for Yves Saint Laurent who also owned the Majorelle Garden right next to it with all the walk and waterways made from Tadelakt. He was very humble and taught us a lot, you could tell he himself works mainly by knowing and feeling the material and he had a lot of patience (a thing that I lack) but he could also be really fast when needed without stressing (which would happen to me). When working on a wall you really have to do the whole thing at once, starting from the bottom up and once you are done with the whole thing it is time for the next step, no time to kill with mint tea and Moroccan delights there. But since I was able to do it in 45 degrees heat in Marrakech I hope I can do it in the Okanagan (Indian) summer”

Nicole is planning a Tadelakt workshop in the very near future on her home in Western Canada’s BC interior , I plan to attend and help her put this together,no times or dates as of yet …interested?? just let me know here.

Here are some shots of Tadelakt from the “Red City” of Marrakech

The Lime Plaster Company

Authenticlime — Fri, 02 Apr 2010 23:40:07 +0000

Heads east …Ben Scott, talented owner of the lime plaster company has left Vancouver for greener pastures, and landed in Georgetown Ontario. Good luck Ben and keep in touch! At least keep your blog updated so we can all see what you are doing

Limestone Plaster is it Real ?

Authenticlime — Thu, 11 Mar 2010 06:32:17 +0000

This is the first of a two part series, of two projects we completed recently……

One of my contractors was faced with the challenge of having a Limestone or Travertine lintel fabricated and installed.So like any good contractor does when he does not already have the resource in place, he asks his best trades the ultimate question ” Do you know someone capable of doing this limestone header for me” he asks,as he is showing me the elevations. Not one to ever back away from a plastering challenge, I offered my further services and took on the job myself. Authentic Plaster FX was already fully involved in this extensive interior and exterior venetian plaster project…so why not add some more of our expertise to the project ?

The question is …is it real? and if no,how did we do it? Well the ins and outs of how it is done I will keep to myself ,and some applicators may offer there insight into how it is done ….but I’ll leave em guessing I’m afraid in this case

Here’s 2 shots of the start of the process,the rest stays under my hat!

So what makes this so important you may ask?…..

Well with this system we can create Limestone details at a fraction of the cost of real limestone or travertine….in this particular case we saved the home owner approximately $8000.00 as compared to having a real limestone header fabricated ,on top of that we did it in a matter of days as compared to weeks for actual real stone,and we are able to get over any building imperfections because the process is done in-situ.
Here’s a sneek peek from part 2 next week

Making lime plaster and mortar,a lost art

Authenticlime — Mon, 14 Dec 2009 04:24:07 +0000

The World is our Oyster

Check out this video from the Colonial Williamsburg video library showing the building and history behind a lime rick .

As the rick burned, temperatures of at least 1800 F were were obtained. This is essential if the conversion from calcium carbonate to calcium oxide is going to occur. Ricks were constructed with several tiers of logs supporting layers of smaller logs then covered with the oyster shells.

There are worldwide examples of historic Lime ricks, these were found in close association to shell middens, which are strewn along the eastern seaboard of the USA, with some examples here in western Canada,with further examples worlwide.

The world-over you will see the use of the sir name “Lime-burner” or points of interest called “Limeburner point” “Lime burner bay” or pubs called “The lime burner” or “Limeburners Arms” these are all in reference of the old trade of burning limestone or in this case oyster shells to make lime plaster, mortars, tabby cement and concrete.

Shell or lime middens are a whole different topic to which I am no expert,but I find the subject interesting none the less.

Shikkui Plaster ( Shirokabe) the traditional Japanese lime plaster, is manufactured in much the same way, from the millions of pounds of oyster shell produced from the consumption of oysters in Japan….albeit in a more modern type of lime kiln.

Shikkui Plaster is made of slaked lime , seaweed extracts and natural plant fibers and other aggregates. Has been widely used throughout Japan for both internal and external wall and ceiling finishes of houses, temples and castles, for over one thousand years.

The hydraulic lime used in the technique of Tadelakt plaster was/is manufactured in much the same way ,in ground pits or pit kilns, with palm fronds as fuel to burn the limestone local to Marrakesh.

The renewed interest in the use of Lime Plasters,Venetian plasters and lime based mortars and paints is beginning a revolution.

Lime Plaster, high in alkalinity and very breathable provides healthy environments, excellent luminescent, reflective light, and simply a beautiful surface wall finish for any home.

Down to earth Tadelakt

Authenticlime — Wed, 05 Aug 2009 14:16:20 +0000

Stumbled upon this blog with some great photography from a Tadelakt workshop

Tadelakt in France

Our workshop in France had an additional workshop within our workshop. Two Moroccan/French masons were there to teach “tadelakt,” a method of burnishing or polishing lime plaster and then sealing it with black olive oil soap. We had brief exposure to it some years ago from a young guy who had studied it in Morocco.Since then, we’ve collected numerous accounts of how it is done and as one would expect, those accounts differed enough to make our French opportunity all that more valuable.

Read the rest of the blog here The Canelo Chronicles

Athena and Bill I’ll guess that you have more shots from this workshop…I know I for one would very much appreciate to see them.