The trouble is sometimes, (i don't know about you lot) but for me i sometimes feel like that by telling the customer how rough there current prep work is i'm sort of calling them a mug for hiring the person who was doing it and at the same time i don't like slatting off another tradesman work, especially if they are due to come back on site.....
I had the exact same situation a couple of weeks ago, it caused me so much grief and has demolished any order i had in my diary....
Never again will i follow on from a builder without having clauses in my quote that if i can't work for whatever reason then it's a charge 'by the hour' or 'by the day' and all extra work carried out will also be a charge. I had a nightmare on my job with the builder there......... I ended up doing tons of extra work in 2 bathrooms which i told him i'm charging for (which he agreed to) but at the end of it when i asked him for the money he didn't want to pay saying it was always part of a tilers. We had a massive row which very nearly came to blows!! after all the work to then have to argue etc etc........... at the end of it i got my money though
I woul be as up front as possible with the customer mate and i would be clearly statting my T's & C's............ I will from now on. Big lesson learned for me.