Understanding the distinction between non-hydraulic and hydraulic lime is crucial for insulating historic structures. Many period buildings suffer when modern, impermeable materials are applied, trapping moisture and causing decay.  Non-hydraulic lime plasters  are always superior for their exceptional breathability and flexibility, allowing your building to regulate moisture naturally. This is key to preventing damp and maintaining structural health, a challenge often faced by owners of traditional properties. Choose the authentic, sympathetic solution that works with your building.

Beyond synthetic barriers:

true comfort through energy

Insulating lime plaster isn't just about adding warmth; it’s about creating a healthier, more comfortable living environment. Unlike synthetic insulation which can lead to condensation, cold spots, and fungal growths in old buildings, insulated lime plasters naturally manage moisture, reducing humidity and improving air quality. This natural thermal regulation contributes significantly to energy conservation, reducing heating demands while ensuring the fabric of your building can breathe. Experience the difference of a consistently temperate and dry indoor climate, year-round.

The vital role of moisture transfer: preserving your heritage

The importance of moisture transfer cannot be overstated when it comes to the longevity and health of traditional buildings. Insulating lime plasters are created to facilitate this crucial process, allowing moisture vapour to pass freely through the wall structure. This prevents interstitial condensation, timber decay, and plaster failure – common issues arising from less breathable modern materials. Understanding and respecting your building’s unique needs for moisture management helps you safeguard your home and its occupants whilst maintaining its historical significance. 

The importance of moisture transfer cannot be overstated when it comes to the longevity and health of period and listed buildings. Our insulating lime plasters are engineered to facilitate this crucial process, allowing moisture vapour to pass freely through the wall structure. This prevents potential interstitial condensation, timber decay, salt hydrolysis leading to structural damage, and plaster failure – common issues arising from less breathable modern materials. By understanding and respecting your building’s unique needs for moisture management, We can help you safeguard your home and its occupants whilst maintaining your building's historical and Heritage significance. 

A couple of nutshells

After half a century of experience with lime, and a good chunk of that time spent Lecturing, we have already created many pages on this site for people to understand lime better, so if you haven't read those pages, start now!

 

In nutshell number 1, we have :  Non Hydraulic Lime plasters are far superior for internal plastering,  because they have high, natural capillarity, meaning moisture does not get trapped in your walls. This is commonly today called "breathability" by most, but  we  prefer "moisture vapour transferability" because we've never yet found a building with lungs, but have seen thousands with moisture in them, and moisture is necessary in traditional buildings, so obviously  Non hydraulic lime plaster mixes are always preferable.

 

In nutshell number 2, we have : Today the "online world of shopping", driven by our old friend Mark Eting, is full of ready mixed bags, stating amazing  things which really are only focussed on another yacht in Monaco for the company CEO.  They are generally best avoided unless you know, and fully understand, the physics and chemistry that has gone into them.

 

Something you must always  be very aware of is product manufacturers are not making products just for you alone, they must try to accommodate a multitude of needs, so if you were aother lazy kid who didn't focus in your science classes, then don't think you have any right to blame a product, when you are the one who bought it, with no knowledge.

A very simple, and very true old saying is 

"Only a bad workman ever blames his tools"

Natural, sustainable, products can be added to non hydraulic lime plaster mixes to provide greater plaster thicknesses with natural thermal insulation values. Now, straight away we must mention a few important, but very real problems, which  ultimately come down to greed:

Losing a few centimeters from your internal room dimensions really is not a consideration to be getting stupid about, when the advantages for you, your family, your health, your family pets health, and your energy savings are compared. 

That said, for all you wannabe property magnates who are obsessed with floor area profits (firstly don't cry too much when you finally realise  the TV programs don't actually tell the truth)  external rendering can be applied also, using the same added natural products, but obviously in an external render mix, not the same internal plaster mix. (Mix ratios are in our book)

Ingredients

Hemp Shiv:  Hemp is the cannabis plant, and despite today's assumptions, there is a species approved for  industrial use which, once it has been processed correctly, is one of Mother Earth's insulators. Its re-growth speeds make  it extremely sustainable, and being natural, there are no harmful chemicals or bonding agents (as often found in modern day insulation materials) to be concerned with. When incorporated into lime plaster and lime render mixes, in appropriate quantities, It provides good thermal insulation without compromising moisture vapour transferability

 

Perlite : Perlite is an amorphous volcanic glass that has a relatively high water content, typically formed by the hydration of obsidian. It occurs naturally and has the unusual property of greatly expanding when heated sufficiently. It is an industrial mineral. Perlite occurs natural and will greatly expand when heated, making it an excellent "aggregate" substitute for aggregates, especially when used in hot mixed lime plasters and renders, it is also around 40 - 50% lighter in weight than conventional sands/aggregates, increasing the overall coat thicknesses that can be applied, and subsequently increasing thefinal thickness (50mm thicknesses are easily achievable with insulating plasters and/renders.

 

Cork : C ork is another good insulator, due to both its thermal and sound reducing qualities, whilst not hindering necessary moisture vapour  transferabilities. It is also lightweight when added in its correct composition and correct quantities. 

 

So by now you can see some of the various options that are available, with beautiful lime. Obviously, when correctly applied and cured, they can easily be decorated with appropriate moisture vapour permeable (MVP)  coatings, both  internally and externally.