Masonry Restoration Using Natural Hydraulic Lime

Do you have a masonry restoration project and are looking for a unique exterior or interior finish for your home that's naturally beautiful? Put aside that wood siding or hand-cut stone and opt for the smooth finish of Natural Hydraulic Lime. This wonder product achieves a look similar to stucco, but with more of an earthy appeal.

Spanish villa, contemporary beach house or modern family room - using natural hydraulic lime (or NHL for short) is an incredibly unique way to create a durable wall.

What Is It?
Without all of the usual technical mumbo jumbo, natural hydraulic lime is sort of like cement but is made with lime. It is truly all natural, containing basically water and lime mixed to a spreadable consistency that dries into a solid state.

Some products come with additives, but pure hydraulic lime has everything going for it. The material has a built-in resistance to bacteria and plant growth. That means mold, mildew and moss won't be a problem. NHL won't break down from exposure to salt either, making it ideal for coastal and marine applications.

How Does It Go Up?
Here's the bad news. Natural hydraulic lime is not the best DIY project around. Unless you have the skills to plaster your home well, this project calls for a professional.

A durable surface will require at least two--and more likely three--coats of NHL plaster. To properly cure the product, you'll need to leave 7 to 14 days between each coat; not the fastest method of finishing your home.

But remember that hydraulic lime mortar is completely recyclable, considering it is made of a naturally occurring material and can be used as fertilizer, aggregate and even in wastewater treatment.

Other Green Benefits
There are no contaminants in NHL and there is zero risk of pollution from the material. Saint Astier's Natural Hydraulic Lime was actually awarded the LABELVERT EXCELL in France for excellence in the field of green building materials. Vive le NHL!

The manufacturing process is also green, using only one quarter of the energy it takes to produce the same amount of cement. Need an added bonus to convince you? Hydraulic lime also reabsorbs carbon dioxide while curing, which cuts back on its footprint even more.

This isn't new technology. NHL has been in use for over 150 years and has been green for that whole time. Not a bad history and a great choice for the exterior and interior finishes on your home.

Photo courtesy of TransMineral USA

Diana Dart | Comments () |

Charmaine

Pleaase remember that NHL is ALREADY premixed with SAND, then imported, so you are paying for the weight ofr sand in the bucket. It is already very pricey, but adding the 70%+ sand in the pail is prohibitive for most. NHL found after a few years of sales in the USA that buyers added the wrong sand, or non-varied aggregate sand (all small or all large particle) or used beach sand/playbox sand which is ALL round, and wont make the grip/locking that varied sand does. Sand is critical to the success of ANY lime plaster or mortar, so you are paying for this expertise in a preblended mix.
So, yes it is necessary to have some skill in application to not waste the NHL, and worse the NHL sets up quickly, like cement- so you do not have the time to mess around.
Practicing with a bag of regular hydrated lime- soaked in a tub of water, to make putty, then troweld, or applied to walls gives you time to make mistakes, learn, and only costs about $9.00 for a 50 pound bag of pure lime ( High Calcium or Dolomitic lime, type S or N are what to buy) DO not buy agricultural lime for $2.00 a bag- the price is your first clue, then read the bag.

Transmin

Charmaine,
Please refrain to make comments which are simply wrong. NHL is not a product which is premixed with sand.
NHL, per definition, cannot be sold as such if anything is added to it. NHL is a binder, not a premixed product. It can be sold mixed with sand, but in this case it would carry an other name, like the EcoMortar, which is a blend of NHL and sand. By the way, the sand is local and as well as the blending process.
Further more, in most cases, the NHL is used simply with local plaster on masonry sands.
Your statement of NHL "setting up quickly, like cement, so you do not have the time to mess around", shows a certain lack of knowledge about NHLs. The NHL has an initial set comparable to portland cement, which allows for the material to hold and make it possible to achieve thickness in plaster and resistance in mortar beds. However, contrary to Portland cement, this initial set is reversable, up to 24 hours. For example, you can mix one batch and use it up to 24 hours later after remixing it. You have plenty of "time to mess around", contrary to what you say.
Maybe a visit to www.limes.us or other reliable source would help.

Katy Ryan Schamberger

Charmaine, thanks for such a thorough reply and your helpful tips, especially the note on realizing that NHL sets up very quickly, so you don't have a lot of time to waste when applying. Your expertise is appreciated!

Allison

Love it. Why don't we hear more about this?

Masonry Restoration Using Natural Hydraulic Lime

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