Hemp Lime Wall materials
The first Australian BCA compliant Hemp-lime building material available for the construction of energy efficient non-loadbearing walls.
We supply AHMC Binder in 9kg and 18kg bags for 120L or 350L Pan mixers.
The Building-grade Hemp Hurd AHMC supplies is sourced from Australian farmers.
Hemp Lime Render
AHMC Hemp-lime Render was formulated to retain the breathability and benefits of Hempcrete walls.
It is also an excellent vapour permeable render for other natural building materials, or on conventional masonry or brickwork.
Available in 9Kg and 18Kg bags.
Hemp Lime Insulation
Insulation for roofing or subfloors completes an effective thermal and acoustic envelope, significantly reducing energy costs and storing carbon.
Forming a light airy breathable wafer, the Lime binder protects the material from flammability and has antifungal and anti-bacterial characteristics.
AHMC Hemp Lime Binder
AHMC’s Lime Binder was developed at UNSW and is manufactured in Sydney. It is the first Australian hemp-lime building material available for the construction of non-loadbearing walls. When installed as specified, AHMC Hemp lime building materials are certified as complying with the Building Code of Australia.
Combined with Building-grade Hemp Hurd which we source from Australian suppliers and water in the prescribed proportions, AHMC Binder creates a light, durable, high quality, highly energy efficient, carbon neutral Hemp lime building material with excellent flexural strength. Where the goal is beautiful off-form internal feature walls, we recommend the inclusion of some sand.
Suitable for non-combustible, breathable, thermally efficient exterior and interior walls in new single and multi-storey residential or commercial buildings, renovations and in retrofitting projects where improved energy efficiency is the goal.
Available in 9Kg and 18Kg bags for 120L or 350L Pan mixers.
AHMC Hemp Lime Render
AHMC's Hemp-lime Render was formulated to reflect the breathability of the AHMC Walling material. It requires the addition of 28 Kgs fine washed sand and 10L water. Available in 9Kg and 18Kg bags.
It is also an excellent Render for other natural building materials, or on conventional masonry or brickwork.
The Render includes hemp fines to give the rendered wall a slightly textured finish. This Render can also burnished to create a smooth finish. Where preferred, once the Render is applied it can be sponged to bring the small slivers of hemp into clear visibility. (Where the hemp is exposed in this way, the render should be coated with a clear breathable sealant such as Murobond Mineral Silicate matt clear to avoid any discolouration of the hemp. It is a woody product and will get weathered and change colour if left exposed and unsealed.)
AHMC Hemp lime Render can be coloured using alkali-resistant mineral oxides. Chemical oxides should not be used with lime products.
AHMC Hemp Lime Acoustic and Thermal Insulation
ROOFING
One of the major advantages of using a very light Hemp lime mixture as roofing insulation is that unlike with insulation mats, or batts, the insulation does not compress down over time. This pest and rodent resistant product is also an acoustically effective material. Forming a light wafer, this high performance material creates an effective thermal and acoustic envelope, maximising airtightness, operational energy efficiency, dampening the transfer of sound and significantly reducing energy costs. Our materials have been specified and out-performed expectations as an acoustic buffer under the Sydney flightpath.
Hemp lime roofing insulation is raked into place with minimal compaction to form an insulation wafer. It is important to take care that all gaps are filled.
Where the roofing insulation is installed from outside, temporary planks or battens should be attached to give the installer additional security. All safety precautions associated with working at heights must be observed. The material should be protected from rain and should be covered as soon as possible.
SUBFLOOR
The same lighter hemp lime formulation that is using in roofing insulation can also be used as high performance acoustic and thermal subfloor insulation and as insulation for suspended floors. The material has high vapour permeability, high elasticity and flexibility and it is an excellent insulator.
As with walls, all electrical conduits and plumbing need to be fixed before the hemp-lime insulation is installed from above.
The formwork or cladding which is usually either 12mm magnesium oxide board or a composite wood sheet is attached under the floor joists and this must be supported appropriately when the insulation has been freshly installed.
R VALUES
- Depending on the climate zone 150mm – R3 to 250mm – R5 of hemp lime insulation is recommended for roofing in Australia.
- In extremely cold climates up to 300mm of roofing insulation is used.
- For floors a minimum of 100mm – 150mm of hemp insulation is recommended.
- For R values
WEIGHTS OF WET AND DRY MATERIALS
- While this is a fast drying material (generally installed and covered with the roofing on the same day), the roofing (or flooring) engineering must be designed to support the damp weight of the insulation material.
- The weight of freshly mixed (damp) insulation material is 351 Kg per cubic metre
- Dry weight is 171 kgs per cubic metre.
Notes: Synthetic insulation materials such as polystyrene or polyurethane should be avoided in hemp lime construction because they compromise the breathability of the hemp-lime walls.
It is also normally not advisable to place an insulation quilt or batt directly in contact with hemp masonry, as moisture when the material is initially cast, can migrate to the insulation material.
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