Concrete slab on top of chimney re-attaching?

andre_xs

Dear All,
I hope the title is not too confusing  

Our neighbour had roofers over today (emergency, roof was leaking). They knocked on our door and told us that on our chimney, the concrete slab which sits on top of the chimney brickwork is loose. He had his colleague climb over on our roof (not asking us, he was so quick, just walking from neighbour's to our roof) and lift it up to show it is loose (and we could see a bit of debris falling down outside, and also hear falling it into our (closed) fireplace. They said it should be fixed again, they'd do it for £350 (Greater London area).

We surely wouldn't use them, because they behaved like cowboys. But I would like to know whether this needs to be done. They said in a storm it could blow down and then do heavy damage. The damage if it falls down sounds reasonable, but I'm not sure that such a heavy slab with no large front/face towards wind/storm could be blown off at all? I presume it will be fixed with some mortar or alike?

Many thanks &
Best wishes,

Andre

tacpot12

You really need an expert to confirm this. If you rely on advice from the Internet, your neighbours could argue that you had been negligent in not seeking professional advice. 

I would suggest that you consult a RICS surveyor and ask them for advice, and to provide you with something in writing if their advice is that it is safe to leave it where it is. They might charge £100 for such a letter, but this is cheaper (and safer) than having anyone go up onto the roof to fix it down.

If I were fixing it, I would use mortar and four large wall plugs (e.g. Fischer SX) into the tops of the bricks plus stainless steel screws and plates for ridge/hip tile fixing (you can get small quantities of these off eBay).