- Natural air lime: highest purity lime containing min 90% CaO, classified as CL90S according to EN-459-1 standard
One of our unique products is RINZAFFO MGN, a plaster developed in 1980 in Venice to the problem of rising damp, penetrating damp and salts, however the origins of this plaster stretch back to ancient Roman times.
Rinzaffo MGN is a breathable, waterproof and salt-resistant lime plaster suitable for a wide range of specialist applications such as:
The RINZAFFO MGN system, due to its unique pore structure, prevents the crystallization of salts inside its pore structure. By regulating the evaporation of humidity it prevents the rapid crystallization of salts, preventing the detachment of plaster, the crumbling and deterioration of masonry.
The life expectancy of the plaster is extremely long. Even in “heavy-duty” damp and salty environments, if applied correctly, it can last over 40 years.
By adding volcanic sands and ashes (natural pozzolans) to the lime, the Romans have developed a wide range of lime plasters for a very wide range of applications - including many waterproofing applications which today are solved with modern Portland cement. Some of these Roman lime plasters were able to set underwater, being suitable for very damp environments. The longevity of these plasters was also outstanding, many of them lasting for centuries.
How can a lime plaster be waterproof and breathable at the same time? Modern research1Arizzi, A. & Cultrone, G. Aerial lime-based mortars blended with a pozzolanic additive and different admixtures: A mineralogical, textural and physical-mechanical study. Constr. Build. Mater. 31, 135–143 (2012). https://doi.org/10.1016/j.conbuildmat.2011.12.069 gave us a better understanding on how these plasters work. It all has to do with the pore structure of the material.
Normal lime plasters are macroporous, which means they have relatively large pores. Looking at their pore size distribution, most pores in air-limes are between 0.1 to 1.0 μm, with some larger pores in the 5 to 50 μm range.2 Santos, A. R. L. dos, Veiga, M. do R. da S., Silva, A. M. dos S. & Brito, J. M. C. L. de. Tensile bond strength of lime-based mortars: The role of the microstructure on their performance assessed by a new non-standard test method. J. Build. Eng. 29, 101136 (2020). https://doi.org/10.1016/j.jobe.2019.101136
Liquid water can only circulate through pores larger than 0.2 μm in diameter. Water can't penetrate pores smaller than 0.2 μm. Due to their pore distribution, normal lime plasters allow the passage of both liquid water and vapours.
The addition of volcanic ingredients to lime, depending on the type and quantity of volcanic materials mixed, can change the pore size of lime plasters. The right mix and quantity of volcanic ingredients can reduce the pore size under the critical 0.2 μm threshold, making some of these lime plasters completely waterproof while retaining their breathability.
Thus Rinzaffo MGN is an open-pore microporous (small pore) lime plaster that acts as a breathable water and salt filter. Its small pores stop liquid water. Its open pore structure allows the wall fabric to breathe. Its small open pores are impervious to salt penetration and crystallization, being free of crumbling and decay. This results in an extremely long service life of this plaster (several decades) even in very damp and demanding environments (e.g. basements), lasting much longer than any NHL plaster or other waterproofing, dehumidifying or restoration plasters operating on other principles.
The Rinzaffo MGN Roman lime mortar differs significantly from today's modern NHL (Natural hydraulic lime) mortars.
NHL mortars are made of lime and clay. These need to be fired at higher temperatures (around 1200 °C) than normal air limes (850-900 °C) for the lime and clay to react. The higher temperatures partially close off the pores of NHL plasters, making them less breathable than air lime plasters. Thus, NHL plasters trade-off some breathability for improved water resistance.
The Rinzaffo MGN, based on an old Roman recipe, uses lime and a variety of volcanic sands and ashes. These are mixed to the lime at room temperature (without heat) as the volcanic sands and ashes have already been pre-burnt by the volcano. This retains the open pore structure resulting in high breathability. The volcanic ingredients make the plaster highly resistant to dampness and salts, making these Roman mortars perform extremely well in damp and salty environments.
This product has won or been nominated for the following industry awards:
Here are some of our projects using this plaster:
This material can be used in the following applications or solutions:
Here are some photos demonstrating this solution. Click on any image to open the photo gallery.
The Salt Warehouses of Venice (Magazzini del Sale) date back to the beginning of the 15th century. They were built to store a very precious trade commodity: salt. Situated across 9 large halls, the salt warehouse could hold up to 4500 tons of salts.
As a result of its location (Venice) and its use (a salt storage) it is probably the most salty building fabric in the world. The only lime plaster capable of withstanding such an extremely salty environment is the Rinzaffo MGN Roman salt-resistant base coat. This plaster is also gentle to the historic fabric – when it reaches its end of its life, it comes off gently without damaging the underlying historic (in this case the nearly 600-year old) wall fabric.
Here is a 200 year-old listed building in a valley, with very high water table and thick stone walls. It has been fully refurbished and thermally insulated with the MGN breathable lime insulation system.Â
Waterproofing the service area of an old crypt with traditional Roman lime waterproofing and Cocciopesto plasters. On some parts of the room the MGN Lime-Pozzolanic Tanking Slurry System has also been applied to reinforce the waterproofing in critical areas.
Here are some videos related to this solution. Please unmute the videos when playing them.
Here are some other similar products of the same category (e.g. other main coats or finishes). Depending on your application, you could use these as alternative products.Â
Although all MGN plasters can be used on their own, in many applications they perform best when certain materials are applied together as a plastering system complementing and reinforcing each other.
Here are some other plasters which are recommended to be used with this one.
If you have any questions about a project, a problem, a solution, or any of our plasters - please get in touch.
We understand that each project is unique. Using the contact form below feel free to ask us any question. Give us as much detail as you can about your project so we can get back to you with more relevant answers.Â
Here are some client testimonials:
I agree, I can see with my own eyes how the Rinzaffo is dealing with moisture. I’m actually amazed by the product. It’s a difficult product to work with initially, but we have to understand that this is not the finish. I have seen with my own eyes how it is dealing with moisture. There are a couple of walls that I can see need 3 or 4 mm extra.
To breathably tank a building like Romford farm is unknown. I must admit I was dubious at the start, but open to the idea. There is no modern building products that I am aware of, or am used to that could possibly be an alternative.
I can see with my own eyes and other senses how the dampness in that building is disappearing the more work that we do. … You have to understand …. I entered that building early on…. It was rotten with moisture. I would say inhabitable. Day by day it gets better.
Here are some key technical points about how to apply this material correctly:
The plaster application video below explains the concept in detail.
