Member Stories: My SheepWool Loft Installation Project

by Blog

Carbon Co-op member Carla Smith has recently carried out a self-installation of SheepWool loft insulation. She has shared her experience of carrying out this project and the planning and thinking which went into the work. This is just one example of how you can carry out DIY retrofit activities, and does not represent an endorsement of these materials or method. Each home will be different, and may require different measures improve the conditions.

1. Moving House

Two years ago we left our Energy Efficient A rated ex-council home to move into our ‘dream’ home – an attractive, but somewhat neglected, draughty and poorly insulated Victorian Semi. 

2.The signs of things to come

The focus on the loft started with an advisory in our building survey –  to check that the chimney stack, removed at the first floor was supported above in the loft space – which was then boarded out as an office.

Unsupported chimney stack in loft.

Breaking through boards to check the remaining chimney stack in the loft – a structural surveyor confirmed that a steel support was needed.

It was also apparent that the damp smelling loft space was lacking ventilation and was visibly trapping condensation, as shown by the large patches of black-spot on the loft wall coverings.

3. The problems

Stripping back layers to install the steel support for the chimney, revealed more problems in the loft!

Rubble and old insulation littered floor joists and was piled up in the eaves preventing ventilation; the timbers all looked, smelled and felt damp. 

You could also see daylight around the sides of the loft hatch when looking up at it – all our heat was escaping up from the house into the loft.

4. The effects

Having been in the house for a year now, we were noticing the rapid heat loss, in particular the extreme temperature fluctuations in the bedrooms, which were freezing cold in winter and stiflingly hot in summer. 

5. Understanding the effects and remedies

As a member of the Carbon Coop, I’d learned enough at workshops to know that there are many types of insulation available. Setting about to educate myself some more, I discovered that almost all insulation is made from waste products, that the manufacturing process of many insulation materials pollutes water, some products gave off harmful gasses and unpleasant things you wouldn’t want to breathe in, while others would need replacing if they got wet!

Finally after eliminating all of the above, I compared the remaining for insulation R-values, fireproof ratings and whether it was infestation proof. 

Now fully confident in my decision, the clear winner for us was SHEEPWOOL. It had the lowest carbon footprint in manufacture and the most competitive insulation values for our ‘cold loft’. As well as being hygroscopic (absorbing) humidity, air purifying and breathable; SheepWool is an amazing insulation material that ticked every box and was well worth the cost.

6. Starting the work

During the loft clear-out we installed a humidity monitor. Initially it showed concerning daily readings above 80% it said WET! We were also able to feel the dampness.

Humidity readings – up to 60% is classed as DRY, above 60% is classed as WET.

SheepWool insulation with new raised loft floor

Despite our continual wet readings, we were reassured, that while measuring humidity and the temperature of a space, the fluctuations inside will be ambient with the outside. Also changes to ventilation, draught-proofing and insulation can control and regulate humidity and temperature too.

7. Creating Ventilation

We cleared the rubble and the old insulation from the eaves. Feeling we needed more ventilation, we opted for ‘easy installation’ Manifold Felt Lap Vents. Slotted between the felt and the roof tiles to open up a small gap, allowed more airflow into the loft space.everything up there to dry out.

8. Drying out the loft

The absence of ventilation and 20 plus years of accumulating condensation of the cold and hot air clashes of the colder months, had made everything in the loft damp, including the timbers and even the rubble. 

The impact of freeing the loft space of all the boarding and debris, enabled everything to quickly dry out. It was very satisfying to see and feel the revival of such an unhealthy space. 

9. Purchasing the SheepWool

Comparing the sheep’s wool insulation products available, we chose 100% sheep’s wool from SheepWool International.

The customer service, help and advice about installation, the product and amounts of insulation needed was honest and professional. It represented all we’d learned and checked ourselves prior to speaking with them. 

10. Installation of the SheepWool

Having crawled about for hours at a time in stifling PPE while removing the dust and rubble from the loft – laying the SheepWool in the now clean and dry space was a pleasure and a victory! 

The insulation recommended thickness to achieve the building regulations U value of 0.16 with the SheepWool is 250mm of SheepWool’s comfort insulation.

Going with the 250mm we laid two layers, laid cross-hatched achieving a U-value of 0.168.

Cross-hatched SheepWool insulation.

Being a soft and natural product, we didn’t need to wear any PPE. The product was presized to fit between our joists, and we simply rolled it out being mindful to stop at the bricks in the eaves as instructed. 

11. Immediate Effects and an Investment

As soon as the first layer of wool was completed during our lockdown Summer, the rooms below, formerly sweltering on hot days, were now much more temperate and comfortable. 

As we fitted a raised storage floor above the first SheepWool layer, the air quality was much improved and cleansed of the damp, dusty humidity. Even as it rained outside the air felt completely dry and airy.

12. The Seasonal Test

As Autumn approaches, we  have the second layer of SheepWool to lay and the loft hatch to draught-proof and insulate.

I am making a cushion filled with SheepWool to put on top of the hatch. We’ll use draught excluder tape on the gaps around the edge of the hatch. 

No longer do we dread going up into the loft. And we’re completely confident we won’t be losing any heat through the roof now!

To share your DIY retrofit project send an email to membership@carbon.coop. Join up as a Carbon Co-op member today!