EDITED POST AS I WAS REFERRING TO THE PROBLEM AS BLOWN PLASTER BUT IT WAS IN FACT HOLLOW SPOTS...
We have recently bought a 1930s semi and the time has come to get quotes in. Following advice we have asked 3 plasterers in. Plasterer one said - Even though it's a small room (box room, not much bigger than a double bed) there are a lot of hollow spots. He will dig it out and repair it, making sure all the walls are perfect. He will guarantee the work and it will cost £600. Plasterer 2 said - Hollow spots don't matter, all houses them, will just skim it over. £400. Plasterer 3 is coming today.
Obviously we want to pay as little as possible but who is right? Is plasterer 1 just trying to justify his price or will plasterer 2 leave us needing to redo the job in a few years?
Can anyone advise?