Natural Insulation Ideas?

[massaira]

Hello all,
Planning to restore a traditional house in Greece and looking into natural insulation options…I am particularly concerned about breathability and management of moisture and have been reading about hygroscopicity and, from what I understand, the possibility of moisture being trapped between the insulation and the wall?
Could anyone please share knowledge on best natural insulation options for period houses, especially with regard to this issue of interstitial condensation? Have been looking into wool insulation, especially one by isolena which doesn’t seem treated with insecticides, but wondering if there is a more budget friendly option to the same effect? Architect mentioned stone wool so far, any opinions on this?
Also, one issue I’ve noticed with the house (which has a stone built, low ceiling ground floor and two lighter, wooden frame upper floors) is, understandably, a big temperature difference as you go up… especially now it’s summer, from the very cool ground floor to a very hot top floor. Wondering if anyone had the same experience and about any ways to address this, through different kinds of insulation perhaps? or any tips really?
Thank you so much for reading to the end! I apologise if I sound ignorant, in the beginning of it all and thankful for this forum, it’s a treasure trove of information!

 

[Lacan07]

There's wool, wood fibre, hemp.

There's also a product called Thermofloc which is recycled paper. Its cheaper than wool, has better insulation numbers, but its loose fill.

 

[skinnymalinky]

Yassou @massaira Properties in Greece are usually very different to those in the UK so some pictures could potentially help here.

It sounds like you need to insulate the roof of the building or potentially the top floor. Insulating the walls is going to be a lot more challenging and would need a lot more careful planning so it might be sensible to focus on the roof first of all - if this is possible. You will need to ensure there is adequate ventilation in this space before adding any insulation.

Stone wool (Rockwool is the main brand in the UK) seems to be a popular compromise option as it is cheaper than sheeps wool, wood fibre, hemp, aerogel, sisal, etc. and Rockwool at least claim that it is breathable - although they are a company that obviously spends a lot of money on marketing and I wouldn't really know how accurate this is when good 'breathability' is essential. For example, people probably feel OK to use stone wool to insulate a well-ventilated loft but perhaps would be hesitant to use this on their walls where there is a greater chance of hidden condensation issues - in which case, wood fibre, sheeps wool, etc would be preferred.

I think the Isolena product you are referring to is a great option but I imagine very expensive. There are (relatively!) cheaper sheep wool products in the UK (Thermafleece; again good at marketing) but these products are not 100% wool and are treated with borax as a moth repellent, which is an inferior method compared with the Isolena 'Ionic Protect'.