I'm in the uk and in a house built pre 1900. In there I have rock wool on top of old rock wool and vermin are finding this very inviting (found out after I bought the house).

Because of the smell and general sloppyness of the insulation I want to go rigid 1) so I can gut the loft and find points of entry 2) So it's harder to make bedding out of the insulation if they still get in and 3) because I want to overboard for storage and potentially convert in the future to a master ensuite.

I've seen this post:

Can I add insulation to my attic and put down plywood so I can walk around more easily?

But it's more for the US market and UK regs tend to be different...Basically I want to adhere to UK building regs for minimum thickness of loft insulation but using rigid foam insulation between rafters and then overboard.

Any help appreciated...trying to search online yields results that would make sense to someone familiar with regs and R values etc but I'm just a DIYer unfortunately.

I'm in the UK and in a house built pre-1900. In there I have rock wool on top of old rock wool and vermin are finding this very inviting (found out after I bought the house).

Because of the smell and general sloppiness of the insulation I want to go rigid

1. so I can gut the loft and find points of entry
2. So it's harder to make bedding out of the insulation if they still get in and
3. because I want to overboard for storage and potentially convert in the future to a master ensuite.

I've seen this post:

Can I add insulation to my attic and put down plywood so I can walk around more easily?

But it's more for the US market and UK regs tend to be different. Basically I want to adhere to UK building regs for minimum thickness of loft insulation but using rigid foam insulation between rafters and then overboard.

Trying to search online yields results that would make sense to someone familiar with regs and R values etc but I'm just a DIYer unfortunately.