Common Questions (FAQ)
We have received many questions about our products and insulation in general. Please find a list of common questions and their answers. If you have a question that is not answered here, please free to get in touch with us through our contact page. Please note that more information about our products and installing them can be found on our products page.
Why should I insulate?
The two main benefits of insulating your home are reducing heat loss and saving money on your heating bills. Insulation will also provide a more comfortable climate for your home, by acting as a buffer between the cold damp weather on the exterior and the warm dry environment inside your home.
Why use Sheep Wool Insulation?
There are many benefits in using natural sheep’s wool insulation, the most significant points being that:
- wool can absorb moisture and still retain its superior insulation properties
- wool has a naturally long lifespan and will extinguish itself in event of fire
- wool is perfectly safe to both the end user and the environment
Is wool more effective as an insulator than alternative materials?
Yes. Wool insulation has a very low conductivity which means it is very difficult for heat to pass from one side to the other. To compare wool to other common insulators examine the table below, here the conductivities are given in Watts per meter Kelvin (w/mK) – where the lower value is the better result.Insulation Material Conductivity (k Value)
Sheep Wool Insulation (Certified Europewide CE Value) 0.039 W/mK
Glass Wool 0.044 W/mK
Mineral (Rock) Wool 0.042 W/mK
Cork 0.04 W/mK
The above values are typically measured at 0% humidity (i.e. laboratory conditions). Wool is a significantly more effective insulator once moisture is introduced into an environment, which typically occurs in everyday situations. Your attic may have 60% humidity for example, which will adversely affect materials which can not absorb this moisture. Wool is a hygroscopic insulator, which means it can absorb moisture without becoming wet to the touch and without affecting its superior performance.
How much insulation do I need?
The amount of insulation that you need will depend on the type of your house, where you are insulating and if you have existing insulation in place. For attics in existing houses, regulations require a minimum of 120mm thick of Sheep's Wool Insulation (this is two layers of 60mm). As this is quite low, we typically recommend a minimum of 160mm thick (two layers of 80mm or 100mm+60mm) to return desirable performance and comfort. For attics in new houses, the regulations require a minimum of 240mm thick (3 layers of 80mm) of Sheep's Wool Insulation which is ample for future performance and comfort. For external walls in a timber frame home, the requirement is 140mm thick (60mm+80mm), which is standard and up to 200mm thick (two layers of 100mm) for super insulated homes. Sheep Wool Insulation is not suitable for use in the cavity of block cavity walls. Internally, Sheep Wool Insulation is usually installed to 80mm or 100mm thick between stud partitions and from 100mm thick upwards between the floors for thermal/acoustic purposes. For roofline installations (dormer/cathedral ceilings where the insulation follows the roof shape) the requirement is 200mm (two layers of 100mm) to achieve the desired performance and comfort. There are numerous other construction types, which we can calculate the amount of insulation you need, please contact us for more information.
What if I have glass/mineral fibre insulation installed already?
Most existing houses have at least some level of insulation in the attic. Many houses over 15 years will find that the depth of existing insulation is usually quite small as old glass/mineral fibre will settle over time and will be much less effective. There are two choices here: the existing fibre glass can be removed or Sheep Wool Insulation can be rolled out over existing insulation. If you remove the existing insulation, be sure to take all the proper precautions including gloves and dustmasks. If you decide to roll Sheep Wool Insulation over the existing insulation you will improve the U-Value of your house and you will also minimise the old insulation fibres from blowing around the attic space.
What is embodied energy?
Embodied energy is the energy required to produce the material and manufacture it to a building-grade insulation standard. It is typically measured in kiloWatt Hours per cubic metre (kWh/m3). Wool insulation contains the least embodied energy of any insulation available, meaning that in a very short time, it will save more energy than will have gone into its production. Most common insulation materials will take many years to achieve this break-even point and some will never reach it at all. The embodied energy of Sheep Wool Insulation is 15kWh m-3 (54MJ m-3) which is less than half of that of cellulose insulation and one sixth of that of mineral wool.
Can wool fibres be harmful and should I wear protective equipment?
Wool fibres are not harmful in any way. Recent concern about minute mineral and glass wool fibres being absorbed by the body through the lungs has prompted a number of countries to distinguish certain insulation materials as potentially carcinogenic. Materials of this nature are typically 1-4 microns thick (one-four millionth of a metre), but wool fibres are 30+ microns which are much too large to be hazardous. No protective clothing or equipment is required to handle or install wool insulation.
Do I insulate the floor of the attic or against the roof?
The aim of insulating should be to follow the shape of you living space as closely as possible. If your attic is only used for storage, then you should insulate the floor because if you insulate the roof, you will heat your attic and your energy costs will be significantly higher. If you have an attic conversion, follow the shape of the plasterboard right around (crawlspace floor, walls, diagonal, small attic and back down) to ensure maximum performance.
Do I insulate my water tank & pipes?
Yes. Water tanks and pipes are insulated to protect them from harsh weather conditions which can damage plumbing and cause leaks. Your water tank should first be sealed to prevent dust and unwanted material from entering your supply. The tank should then be insulated around and on top to effectively keep it within the warm part of the house. Leave under the tank uninsulated, this way warm air from the room below will reduce the chances of your tank freezing in severe conditions.
Do I insulate electric wiring?
Electric wiring in the attic is best left on top of the insulation. This will allow easy access for electricians in the future and can avoid heavily loaded wires from overheating.
Can I use wool insulation as a hot water tank jacket?
Yes. Wool insulation can be placed beneath the existing lagging jacket or can be held in place with a layer of old blankets. We are currently prototyping a ready made insulation jacket, which will be on sale in our online shop when released.
Do you deliver ?
Yes. Depending on the quantity and products ordered, we deliver with our own vehicles or we use couriers such as Interlink Express and Fastway. Delivery charges are additional, but we try to find the most cost effective delivery method for the quantity of rolls in your order and where it is being delivered.
Do mice like Sheep Wool Insulation?
Mice and other household vermin are neither attracted nor repelled by any form of insulation. They seek out a source of food and a source of heat nearby to each other. Once insulated, attic and cavity spaces become colder and less attractive to these animals, deterring them from nesting there. The best method to avoid unwanted vermin is to find and close up any gaps that will allow them to enter your building.