CORE PERFORMANCE METRICS (ASSUMED R&D VALUES)
The data below represents our initial research and development calculations. We are a growing independent company and are currently collaborating with specialist consultants and UK-based testing laboratories to finalize official UK certifications and fire safety regulations.
Thermal Conductivity (λ): 0.042 W/m·K (Base performance metric)
Installed Target Density: 11 kg/m³ (Loose-fill hand-packed application)
Composition: 100% Sheep's Wool (Naturally processed, air-dried)
Chemical Additives: Borax treatment only (Insect and fire-retardant standard prep)
Forced Drying: None (100% naturally air-dried to protect fibers)
COVERAGE & MATERIAL CALCULATOR (PER 5KG BAG)
Because Prowool Insulation is a loose-fill product, its coverage is determined by your target installation depth. Based on an installed target density of 11 kg/m³, a single 5kg bag yields approximately 0.455 m³ of expanded volume.
At 100mm Depth (Standard Timber Stud / Base Layer):Coverage per 5kg Bag: Approx. 4.55 m²Material Volume: 0.455 m³
At 150mm Depth (Top-Up Layer):Coverage per 5kg Bag: Approx. 3.03 m²Material Volume: 0.455 m³
At 250mm Depth (Recommended Total Loft Thickness):Coverage per 5kg Bag: Approx. 1.82 m²Material Volume: 0.455 m³
ESTIMATED THERMAL PERFORMANCE & ROOF U-VALUES
The following performance metrics are estimated based on a standard residential cold loft installation scenario (wool laid between and over horizontal ceiling joists):
Total Insulation Depth: 250mm
Configuration: 100mm loose-fill layer between timbers + 150mm loose-fill cross-layered over timbers.
Resulting Estimated Roof U-Value: 0.16 W/m²·K
Note: Actual structural U-values can vary depending on thermal bridging, timber frame sizes, and existing building elements. For exact structural configurations, consult with your building contractor or architect.
WELCOME TO PROWOOL INSULATION – THE 100% NATURAL WAY TO WARM YOUR SPACE
Bring the natural warmth of the Mid-Wales hills into your project with Prowool Insulation. Sourced directly from our family farm and trusted local neighbors, we produce 100% natural, loose fill sheep’s wool insulation designed for lofts, timber frames, heritage restorations, and campervan conversions.We are a small, passionate Welsh company built on pure, sustainable values. Unlike standard industrial brands that rely on automated machines, we choose people over heavy machinery. We wash and treat our wool the traditional way, doing the work by hand. By keeping our processes human led rather than machine driven, we drastically lower our carbon footprint while keeping the quality of our wool as high as possible. This hands on care also allows us to create meaningful local employment and support our rural economy. Our wool is entirely air dried to preserve its natural bounce, structure, and superior thermal properties. We treat it using a traditional borax process to the highest required safety standards. With zero harsh chemicals and no irritating synthetic dust, it is completely safe, soft to the touch, and easy to handle without gloves or masks. Values That Protect Your Home, Vehicle, and Planet:
- Local Jobs & Low Carbon Footprint: By avoiding fully automated factory machines, our traditional hand processing methods reduce energy consumption and directly create and support local employment in Mid Wales.
- High-Quality Material Standards: Rejecting fast mechanical processing allows us to inspect every batch by hand, ensuring we keep the wool quality as high as possible for your project.
- Genuinely Sustainable: Sourced locally from our own fields and neighboring farms, keeping carbon miles to an absolute minimum while supporting Welsh agriculture.
- Breathable & Climate-Controlling: Sheep’s wool naturally breathes. It absorbs and releases moisture vapor without losing its thermal efficiency, actively protecting timber frames from damp and regulating your indoor climate.
- Continuous Safety Advancements: We are proud to be working alongside leading UK-based testing laboratories and specialist consultants to constantly pursue and advance through current UK fire regulations.
- Unbeatable Fiber Integrity: Because we never force dry our wool with industrial heat, the fibers retain their natural elasticity, meaning your insulation won't pack down flat or sag over time.
One Premium Product, Tailored For Every Project:
Whether you are topping up a residential loft, insulating a historic timber frame, or looking for the ultimate hassle free setup for a campervan build, we have a solution for you. Take advantage of our bulk builder rewards, including automated 5% discounts or free insulation netting on qualifying orders.
Loved By Customers, Available Everywhere You Shop:
We are incredibly proud to have earned great reviews across all online platforms for our quality and friendly service. We make it easy to buy wherever you feel most comfortable.
You can shop our range online via:
- Our Official Website
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- Etsy
- Google Shopping
- Facebook Shop & Instagram
Prefer to buy local and see the product in person? We now partner with 4 independent retail stores across Wales who stock and sell Prowool Insulation directly over the counter.
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Whether it’s a loft, renovation, barn, listed building or something completely different, send us your before and after photos and show us how you’ve used Prowool Insulation.
If you’re happy for us to feature your project and photos on our website and social media, please send them over. We’d love to showcase real Prowool Insulation projects and help inspire others who are considering sheep’s wool insulation.
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British Eco Friendly Sheep's Wool Insulation
Prowool Insulation™ is crafted from high quality fleece sourced directly from our farm and a select network of British farmers who share our commitment to responsible agriculture. We hand pick every supplier and ensure they receive a fair price for their wool.
Our on site washing and treatment process is as natural, durable and pests and mould resistant as possible, delivering long lasting performance without harsh chemicals. Choose insulation that supports sustainability, fair trade and the environment. Our sheeps wool insulation is traditionally washed and may contain remnants from the shearing process.
The Sheering Process
Sheep shearing is the annual removal of a sheep's fleece using electric clippers or hand shears, typically performed in spring (May-July) to prevent flystrike and ensure comfort. The process involves a specific, low stress, step by step technique to remove the fleece in one piece, starting with the belly, followed by the legs, neck, and long blows down the body
Is shearing sheep necessary?
Yes, Without shearing, sheep can suffer from overheating, limited mobility, and skin infections like flystrike caused by filthy, matted, or overgrown fleece
Is shearing hard work for the farmer?
Yes, sheep shearing is considered one of the most physically demanding jobs in the world, requiring exceptional strength, stamina, and technique. Shearers often handle and move 150+ sheep a day, working with a heart rate of 140–150 beats per minute, burning around 5,000–5,500 calories daily
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