Lime Green's Ultra lime plaster base coat is a lightweight insulating lime plaster base coat that is five to ten times thermally more efficient than other lime plasters. This makes it the perfect plastering base coat for building renovations, where it gives an additional insulation layer to internal walls and protects against salt damage.
As an insulating lime plaster, Ultra Lime Plaster is such an effective insulator because it contains an aggregate of hollow beads made from recycled glass, which can make up to 55% of its bulk. This replaces the sand conventionally used in standard commercial lime plasters, which means Ultra Lime Natural uses less energy to manufacture and is significantly lighter to transport, so cutting down on distribution costs and energy.
Also, because it is applied as a wet plaster, Ultra Lime Plaster acts as a ‘draught excluder' by plugging any small pores and gaps within the fabric of the wall, something that standard dry-lining cannot do to the same extent.
Ultra lime plaster base coat is applied to walls in the same way as conventional lime plasters. It has good ‘workability' and there are no complicated fixings or problems achieving the right depth of coat.
Completely Mineral
One of the great advantages of a lime plaster is it's mineral content, unlike gypsum and polymer plasters, they do not contain anything which will dissolve in water or rot. Once set, Limegreen Ultra has more than 99.5% mineral content, which also means it has the best possible Fire Classification (Class A1).
Thermal Performance
Ultra is the warmest lime plaster on the market: with no cement and a thermal conductivity of just K=0.11 (lab testing at 0% moisture) or k=0.178 (moisture corrected as per the British Standard) it can be an invisible upgrade to your thermal performance while re-rendering. Some typical real world reductions in heat loss on a traditional 9" brick wall would be:
10mm Ultra = 8% reduction in heat loss
20mm Ultra = 15% reduction in heat loss
40mm Ultra = 26% reduction in heat loss
Please be aware that many insulating plasters only quote the oven-dried thermal values, which can never actually be achieved on site.
Surface Preparation
Remove dust, surface contaminants and loose or friable coatings. Apply a Fungicide if necessary. On dense, smooth masonry backgrounds or high suction backgrounds apply Lime Green Natural Stipple for improved bond. Other primers are available for difficult substrates - contact us for further details.
Mixing
Ultra can be mixed using a drum mixer, or in a tub using a plasterer’s paddle mixer. Mix with approximately 4 to 4.5 litres of clean water per bag; do not add anything else. Use eye protection and dust masks and avoid creating excessive dust.
Application
Only use Ultra above 5o C and below 30o C. Ultra should be applied to a straight, flat, dampened surface in a uniform thickness of between 10 and 30mm, make sure this coat is keyed. After 2 to 7 days and the coat has stiffened/hardened, but is still ‘green’ more coats may be added. Make sure that curing is carried out between each coat (see below). Careful consideration must be given to detailing of areas such as cills and drips, especially on sites exposed to high levels of wind and rain. We recommend the use of a reinforcement mesh (Lime Green 910 mesh) to be applied to the final coat of Ultra when Ultra is used externally. Each section of mesh should overlap the next by 100mm.
Coverage
1 litre per mm of thickness over 1m2 . One bag will cover: 1.5m2 at 10mm thick 1m2 at 15mm thick 0.6m2 at 25mm thick
Curing
The prevention of drying out too quickly is the key to the success of the application. Lightly spray the Ultra in hot weather if it is drying out too quickly. In addition, protect from harsh weather conditions, for example, frosts, rain and direct sunlight. The use of damp hessian, fixed to the wall can slow down the drying out process and provide protection from adverse weather conditions.
Finishing Coats
Suitable fiinishing coats are Lime Green Natural Finish, Lime Green Solo or Fine Stuff, applied once the Ultra has set. Finishing coats should be applied in a uniform 3 to 6 mm thick layer with a trowel.
Further Information
Limegreen Ultra Technical Datasheet
For increased energy savings and thicker insulation build up you could consider the Warmshell Woodfibre system or an insulating hemp plaster which can be cast onsite. Contact us for more information.
