Dense plastic behind plasterboard? Ask your questions and find answers on many subjects relating to plastering and dry lining

[John_W]

I want to put some secure fixings into plasterboard. I used a metal finder to confirm there are are no wires or metal studs and the plumbing is enclosed in boxing. I can push a screwdriver blade 10 cm into the first hole I drilled. When I tried to make a 15mm diameter hole I came across some very resistant dense plastic (or ceramic?) immediately behind the plasterboard and flush with it. Got a bit of a burning smell and stopped. Any idea what this might be?

[stoneyboy]

Hi john_w
I find the stud finders are pretty useless so maybe you've hit some metal sheathing. If it's a modern wall you may have metal studwork. Only you can establish what is behind the plasterboard - enlarge the hole until you can see.
Regards S

[John_W]

Thanks for the advice and sorry not to acknowledge right away. There is a stud that I found around 4cm away, that is wood and metal. The dense plastic seems a bit mysterious. I wanted to avoid cutting too much material away as I'm not experienced with plasterboard repairs. As I have already drilled into it, I can probably use it as an anchor without going any deeper and secure more conventionally at other points. Thanks again, John.