All an indemnity policy does is cover the cost of repair if it all goes wrong, in your case, if the house falls down....
The OP says it’s an RSJ that’s in question. In all seriousness, if it did need doing, you’re only looking at £1k tops - inc. calcs and BC sign off. If you like the house, and the price is right, don’t let it put you off. Just negotiate a little on the price to cover it. There’s worse things out there.
That's not my understanding. It only covers against the possibiliy of costs arising from enforcement action because the council found out. I doubt you could get insurance against costs arising because someone had done a botch job.
That is assuming that in the period before any correction work is done, the insufficient RSJ, or the less than adequate pads it is mounted on, or the lack of pads etc don't cause the whole lot to fall down. I'd walk away to be honest, if the vendor won't budge. Its the vendor's call. The work may be fine and could be signed off if he would only strip back some decoration to have a look. It depends on how desperate they are to sell.
Unlikely to in all honesty. And it’s only your liability once you’ve completed the deal - by which time you’d have a builder lined up to do it before you got everything unpacked. I’ve done loads of RSJ jobs like this, it’s really nothing to be overly concerned of so long as you know about it and book it in to be done (and obviously had a bit of discount knocked off). Like I say, if you really want the house and the price is right, it shouldn’t put you off. There’s probably worse things that’ll show up anyway that have been missed altogether or couldn’t be known by the surveyor