Had a similar scenario last year for a retired builder, had a gaball end of a bungalow to hack off, scratch, float and Tyrolean.
He said he'd be there to help out if and when and I thought the same as you he'd be f**k*d after one day....
On the hacking off stages he was a warrior on the wheel barrows and shovels into the skip, I had a wheelbarrow and shovel and my mate loading it up, he pulled out 2 more wheelbarrows and just kept loading in and loading out.
Throughout the rendering stage he would have all 8 of my water buckets filled up, cement out the shed and sand next to the mixer all plugged In by 7.30am every morning ready for us with a cup of tea at 8am.
Through all stages he went and got a load of old carpet and had it anywhere muck will drop or we would walk, and Tyroleaning was much the same, bits of cardboard cut up and taped over vents etc.
He made the job a pleasure literally the most stress free 5 days ive ever had at work. I had a lot of time for him definitely one of my best customers, I knocked £200 off the bill at the end and told him to get on and have a few on us, little did I know he give us a extra £100 each (2of us) and he said nope, £200 there is your twos drink money. Followed by piss off now before it all falls off !
Legend