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 stands in stark contrast to modern NHL (Natural hydraulic lime) mortars.
NHL mortars are made of lime and clay. These require higher firing temperatures (around 1200 °C) than normal air limes (850-900 °C) to ensure proper reaction between ingredients. The higher temperatures partially close off the pores, making NHL plasters less breathable than air limes. As a result, NHL plasters gain water resistance at the expense of breathability.
The Rinzaffo MGN's ancient recipe combines lime with 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. The lack of industrial heating retains the open pore structure of the mix resulting in high breathability.
Furthermore, in Rinzaffo MGN, a portion of conventional sand is replaced with volcanic sands. Unlike dense quartz sands resembling glass, being impermeable to water vapours, volcanic sands are highly porous, contributing to the plaster's breathability.
Here are the recommended work specifications for this plaster.
[15-20 mm] ABOVE GROUND: Lime base coat, applied as:
[25-30 mm] UNDER GROUND: Lime waterproofing coat or for very damp wall sections, applied as:
Here are some key technical points about how to apply this material correctly. Please have the applicators read / watch the application instructions below before applying the product.
VERY IMPORTANT POINTS
There are a few very important points that MUST be respected for the correct application of this plaster. These are highlighted in red.
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Here are some key technical documents (spec sheets, application guide etc.) about this plaster.
If you have any questions about a project, a problem, a solution, or any of our plasters - please get in touch.
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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.
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.
Some walls of this old farm house have been re-rendered with the Sanacolor 2000 MGN lime render.
This old cottage has been suffering from rising damp for quite a while. As a result the internal plastering has been blown. The long-time fix involves the replastering of the wall with the Rinzaffo MGN Roman salt-resistant base coat, providing a building-friendly fix for several decades.
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.
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.
