Sheepswool vs Hemp

[thebadger7]

Hi folks
I'm reroofing and need to insulate between rafters at same time.
I've used sheepswool in the past, but there seem to be more hemp products out there - has anyone had any experience?

Our rafters are only 6 inches deep, my understanding with sheepswool is that you don't need an air gap if a breathable membrane is used, is that right?
We're also insulating above the rafters with woodfibre sarking boards which will be ventillated from above.

Thanks

Luke

 

[alexander]

breathable membrane still needs ventilation or you will get damp

 

[a twig]

Thermafleece’s own technical guide says you can insulate the full depth with it or partial depending on how you are building up your insulation

https://thermafleece.com/wp-content/uploads/2024/08/Warm-Roof-application-notes-V8.pdf

 

[Kearn]

Thermafleece’s own technical guide says you can insulate the full depth with it or partial depending on how you are building up your insulation

https://thermafleece.com/wp-content/uploads/2024/08/Warm-Roof-application-notes-V8.pdf

Thermafleece will also be a great place for your new moths to live!

 

[thebadger7]

These guys also say you can insulate the full depth so I was unclear: https://www.sheepwoolinsulation.com/where-to-use/attics/

 

[Kearn]

Hi folks
I'm reroofing and need to insulate between rafters at same time.
I've used sheepswool in the past, but there seem to be more hemp products out there - has anyone had any experience?

Our rafters are only 6 inches deep, my understanding with sheepswool is that you don't need an air gap if a breathable membrane is used, is that right?
We're also insulating above the rafters with woodfibre sarking boards which will be ventillated from above.

Thanks

Luke

Depends on what order you’re doing things and if access is available from below also. And how regular your rafters are?

For newer, straight commons, the woodfibre batts are nice and easy to cut and press fit. Also helpful if you’re working from below as they will friction fit. From the top and ggur old variable spaced/shaped commons in an old roof, sheepswool is easier to fill the irregular voids.

There’s nothing in it from a breathability or thermal perspective. Cost also similar.

I use Pavaflex from Eden

Wood Fibre Insulation Products - Eden Hot Lime Mortar

Wood fibre insulation provides thermal insulation both in summer & winter. A high thermal insulation power allows you to save energy & live in comfort

edenhotlimemortar.co.uk

Or sheepswool needs to be from
https://www.sheepwoolinsulation.com/

If you’re adding the woodfibre external boards on top of commons, then you want the infill insulation to be a continuous part of this so it’s all one layer of insulation, no gap, no membrane. Otherwise you’re only insulated by the lower layer and you’ll get cold spots and condensation where you can’t see it.

 

[a twig]

Thermafleece will also be a great place for your new moths to live!

Why? It’s treated with borax

 

[Kearn]

Why? It’s treated with borax

If you’ll excuse the drama of the whole story. The court case ruling is hidden within. There’s been a lot of changes with the company and many issues which haven’t hit the headlines quite the same way.

 

[a twig]

I think there might be a link missing from your post?

 

[thebadger7]

Depends on what order you’re doing things and if access is available from below also. And how regular your rafters are?

For newer, straight commons, the woodfibre batts are nice and easy to cut and press fit. Also helpful if you’re working from below as they will friction fit. From the top and ggur old variable spaced/shaped commons in an old roof, sheepswool is easier to fill the irregular voids.

There’s nothing in it from a breathability or thermal perspective. Cost also similar.

I use Pavaflex from Eden

Wood Fibre Insulation Products - Eden Hot Lime Mortar

Wood fibre insulation provides thermal insulation both in summer & winter. A high thermal insulation power allows you to save energy & live in comfort

edenhotlimemortar.co.uk

Or sheepswool needs to be from
https://www.sheepwoolinsulation.com/

If you’re adding the woodfibre external boards on top of commons, then you want the infill insulation to be a continuous part of this so it’s all one layer of insulation, no gap, no membrane. Otherwise you’re only insulated by the lower layer and you’ll get cold spots and condensation where you can’t see it.

Thanks for the info. Insulating from above as all slates are being stripped and replaced. Woodfibre sarking boards above rafters. Not measured rafter spacing yet but they're not deep, maybe 6 inch