Vertical insulation in the loft

I know someone who did. The main subsequent problem was when he came to a permanent repair, it was really difficult to dismantle the roof as all the slates were stuck to the battens and rafters. None of the slates could be recovered in the end. It took about five minutes to clean up each slate & many broke during removal/cleaning. There was a huge pile of battens, foam and slates to dispose of.

However on a vertical wall it's fine. Works as advertised. But needs to be kept out of sunlight. Not easy to apply evenly. Practice needed.

snips

spray foam...

The problem is behaviour in a fire. Celotex, papercrete and cellulose are f ine, as long as theyre suitably formulated.

NT