Ty-Mawr Lime Hemp Plaster is made from a high calcium lime (also known as a fat/air/putty Lime or non-hydraulic lime) blended with the hemp fibres and a pozzolan to aid the set.
It requires exposure to Carbon Dioxide in the presence of moisture to harden however, it can be applied in thicker coats than conventional lime plasters and is easier and quicker to use.
Like all non-hydraulic lime products, it is extremely flexible and breathable which makes it suitable for use in the restoration of old 'solid wall' construction buildings and ideal as a 'wattle and daub' replacement in timber-framed buildings. It is also suitable in ecological new builds as it can be applied to a variety of substrates e.g. woodfibre boards, wood wool boards, strawbale.
The addition of hemp fibres not only improves the strength and flexibility of the product, it also increases the thermal properties of the plaster and so is an excellent way of adding some insulation to your wall. Please contact us with details of your building so that we can assess the suitability and the likely improvements to performance.
It is available in two grades - medium and fine and is ready to use in 1 tonne bulk bags, 20 kg bags and 20l buckets.
To learn about colour variation please click here
Email firstname.lastname@example.org for a printed copy/copies of the catalogue. Free samples of the dried product on our wood wool or woodfibre boards are also available, contact email@example.com for information.
- Technical Documents
- Application Advice
y-Mawr Fat Lime Hemp Plasters are made from a high calcium lime (also known as a fat/air/putty or nonhydraulic lime) blended with the hemp fibres and a pozzolan to aid the set. The Ty-Mawr product is entirely made from British materials. It requires exposure to Carbon Dioxide in the presence of moisture to harden, however, it can be applied in thicker coats than conventional lime plasters. It has good flexural strength and is breathable, which makes it suitable for use in the restoration of old 'solid wall' construction buildings as well as ecological new builds, it also provides additional insulation, is easier to use and is ideal for patching and improving air tightness.
It should not be used in damp situations e.g. basements or on wet substrates. Good practice should be taken to ensure that the building structure is 'breathing' e.g. removal of external cement renders/plastic paints etc.
Time needs to be given for previously wet walls to dry out if cementitious renders have been removed.
Please Note: The application of lime plaster is more involved than using conventional plaster. It is highly recommended to use a plasterer experienced in the use of lime plasters or at the very least some practical experience is essential e.g. by attending a lime course, as it is not possible to cover every point in detail here.
Please click on the Documentation tab above to download a full version of our Ty-Mawr Fat Lme Hemp Plaster Application Guide. However, should you experience difficulties in applying our products after following the advice given, please contact our Product Support Team at firstname.lastname@example.org.
- Made from a natural, renewable plant fibre (instead of depleting a natural aggregate resource).
- Has greater flexural strength than traditional lime plasters making it extremely durable e.g. it is far more resilient for use on corners, reveal and other vulnerable areas of the building.
- Has thermal properties and can therefore be used to help improve the insulation performance of the wall.
- Can assist with the airtightness of old buildings, improving the comfort of the room and offering energy savings.
- Can be applied in much thicker coats (single coats can be applied between 10-25mm) than traditional lime plaster therefore is especially useful for ‘dubbing out’ hollows in walls prior to further plaster coats.
- Is a successful way of ‘patching’ old lime plasters e.g. where electricians/plumbers have been ‘chasing out’ .
- Is easier to use than conventional lime plaster (minimal shrinkage even on high suction backgrounds) offering labour savings.
- Is breathable and therefore helps to safeguard the functioning and health of the building as well as helping to regulate humidity which makes for a healthier internal environment, this make it ideal for use in older buildings.
- Easy to use - is supplied ready to use, can be mixed in an ordinary cement mixer, there is no requirement to use mesh or add hair.
- As it requires fewer coats and less tending, it can make significant labour savings.
- Is beautiful - the coarse/medium plaster gives a soft textured finish otherwise the fine hemp, glaster or ordinary finish plaster can be used for a smoother finish.
- Lime hemp plaster replies on the correct environment to 'carbonate', if your substrate is wet or there is little heating or ventilation in the property in which you wish to use it, please call us for advice.
What is Ty-Mawr Lime hemp plaster made from?
Ty – Mawr hemp lime plasters and renders are made from the chopped stem of the hemp plant blended with high calcium lime (also known as a fat / putty or non-hydraulic lime). Ours is made entirely from British materials.
What are the benefits of using lime/hemp over a standard lime plaster?
• Ty-Mawr hemp lime plasters requires exposure to Carbon Dioxide in the presence of moisture to harden like all lime hemp plasters, it can however be applied in thicker coats (up to 25mm) than conventional lime plasters.
• It is more environmentally friendly- hemp is a renewable resource which as a plant locks in CO2 as it grows. Using hemp instead of sand also avoids the removal of natural resources from the ground.
• It has better thermal properties than other lime plaster products and can therefore be used as an insulating plaster.
• The addition of hemp fibres dramatically improves the compressive and flexural strenth of the product which make its more durable and stronger that other lime plasters.
What is lime hemp plaster suitable for?
Like all lime products, it is flexible and breathable which makes it suitable for use as a lime plaster in the restoration of old 'solid wall' construction buildings as well as ecological new builds, it also provides additional insulation.
Lime hemp plaster is suitable for backing coats as well as textured finish coats.
Your finished plaster will care for your building for years to come as well as helping to control the humidity of the internal environment.
It can be used externally with caution the detailing, time of year and conditions to carbonate all need to be well planned and executed and a glaster or standard lime top coat should be applied to give protection.
It is often used simply for dubbing out or patching old plaster after the electricians hace been in for example becuase it is less susepctible to shrinkage and cracking and can be applied in single coats up to 25mm, it really is ideal for these situations.
Can it be used to plaster ceilings on your wood wool boards?
Yes it is very successful of these boards but please note for ceilings (heavy stress), onto Ty-Mawr wood wool boards, it is best to include a render mesh trowelled in to the first coat, this would not be required in most usual (light stress) situations. Please see manufacturers build-up tables for further advice.
Please note that 15mm boards are not usually recommended for ceiling applications.
How much will I need?
• 20kg bag covers approx 0.6m2 at 25mm coat.
• 1 tonne covers approx 30m2 at 25mm coat, 50sqm at 15mm.
Is lime hemp plaster applied in a similar way to regular plaster?
Hemp Lime plaster is easier to apply than conventional plaster because of its fibrous properties and minimal shrinkage, it can therefore be applied in thicker coats and requires less tending but otherwise it is similar in terms of control the moisture, environment, protection etc and it is therefore highly recommended that you use a plasterer familiar with fat/non-hydraulic lime products.
Moulds can develop on the hemp if the correct conditions are not supplied, please follow the manufacturers instructions and monitor the situation closely, this is especially important over the autumn and winter months.
How long does it take to dry?
This can vary dramatically depending on the conditions, given the right condidtions, it can take anything between 4 days up to a month or more to completely dry depending upon the substrate, thickness of application, wetness of material and environmental conditions. This should be monitored closely and action taken to adjust the conditions if there are drying issues. Gentle heat, plenty of ventilation and even dehumidifiers may be used cautiously in cold, damp buildings.
How should the plaster be stored?
• Store airtight and frost-free
• Premixed lime hemp plaster will become hard over time and require more ‘knocking-up’.
• Use within three months of purchase.
How can it be finished?
Lime hemp plaster gives a beautiful finish that no modern plaster can replicate, the medium and coarse grades will produce a textured finish. Clients often like the finish and therefore do not go on to even paint. If a less textured finish is required, then the fine hemp plaster or a standard finish lime plaster can be used.
If you do choose to paint it, we highly recommend that you finish it with a ‘breathable’ and preferably a natural paint. Your choice will depend on the level of durability, required vapour control and desired aesthetic - there are a wide range of colours and choices in the paint section of this website that are all suitable.
Does it save time?
It seems that our hemp lime plaster is saving time on site just by reducing the time dubbing out and ending - plasterers have reported time savings ranging from 30-50% in application.
How insulating it is?
Although it has some thermal value it is never going to be as effective as a board or natural fibre insulation batt, but it is more insulating than standard lime plaster. It also helps with achieveing air tightness in old buildings which is a very important factor in improving the energy efficiency of old buildings - see our solid wall insulation sheet for more details.
Is there anywhere I shouldn't use it?
If the fibres remain wet then it can create problems so on a wall that is not likely to dry out (e.g. if there is a cement render or a bank of earth against the wall) externally, then it should be avoided.
It can be used externally but we would advise that a standard lime render or glaster top coat is used for the final top to protect it.
Why would I use a lime hemp plaster?
We would suggest that if you are replacing an old plaster then the increased ease of use and speed of application as well as the fact that it is more enviornmentally-friendly and that it can help with energy efficiency...really speaks for itself! It has many many enthusiastic followers......
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Customer Reviews 5 item(s)
- Very happy!
- We used Ty-Mawr lime plaster with hemp added for its extra insulating properties for the walls of our cottage. We are very happy with the results and performance.
- Sceptical initially but we're absolutely delighted with it.
- I am just writing to let you know that I am absolutely delighted with your hemp lime plaster. We have plastered the interior of our 17th century stone house with this material and painted with clay paint. The result not only looks fantastic, but the quality of the interior environment it has created is dramatically improved compared to the previous gypsum finish. In particular we haven't seen any trace of condensation anywhere. The walls are also noticeably warmer to the touch compared to gypsum plasters. My builders were pretty sceptical initially, but they soon "took" to the material and the plasterer commented on how enjoyable it was to work with.
- An excellent material
- The Lime Hemp Plaster is an excellent material which makes using lime an easy process. The ability to build up a significant depth in one go, rather than numerous layers speeds work up considerably. It is very useful updating of a traditional material. Many thanks."
- It is perfect!
- Thank you to Ty-Mawr for introducing me to the hemp and lime plaster. I really enjoyed working with hemp and lime. I have finished the job ... I am happy, the customer is over the moon ... the job finished quickly ... I put 50mm on the wall ... it is perfect. Thanks again!
- Most versatile and labour-saving lime product on the market
- I think that the Ty Mawr Hemp Lime is the most versatile and labour saving Lime based product on the market which makes the use of lime much more affordable and user friendly for everyone.