I have an uninsulated cavity wall which I want to fill. I don't need to drill holes, since I can access it through the roof. I can't use sheets because it's full of protruding mortar and then won't fit snug. So I am condemned to loose fill or foam.
Although I like the idea of expanding foam, the fuming is a serious issue and has put me off.
I had settled on loose cellulose but due to its water retention + possible mould issues I am less keen on the idea. Bare in mind, the external wall is rendered, and it's in good condition. I have inclined more towards fire retardant polystyrene beads as of late, but I'm nut sure about how fire resistant it is, since it will be in the kitchen.
So, questions:
1. What type of adhesive should I be looking at ? or can I get away with no adhesive and just fill the tops with fire resistant expanding foam ?
2. What possible issues can arise with polystyrene. I know it has a retardant, but reading the data sheets, above 250-500c it does give pretty easily. Maybe I should buy a sample and put a torch to it..
Although I like the idea of expanding foam, the fuming is a serious issue and has put me off.
I had settled on loose cellulose but due to its water retention + possible mould issues I am less keen on the idea. Bare in mind, the external wall is rendered, and it's in good condition. I have inclined more towards fire retardant polystyrene beads as of late, but I'm nut sure about how fire resistant it is, since it will be in the kitchen.
So, questions:
1. What type of adhesive should I be looking at ? or can I get away with no adhesive and just fill the tops with fire resistant expanding foam ?
2. What possible issues can arise with polystyrene. I know it has a retardant, but reading the data sheets, above 250-500c it does give pretty easily. Maybe I should buy a sample and put a torch to it..
