DGDevin wrote
Rod Speed wrote

The way I have solved that kind of problem is by giving the guy a shopping list. "Any questions? Call me when all
the stuff is at your house and I'll be over"

Trouble is that plenty arent capable of using the list properly.

And its often a lot more trouble to make up a list that someone who doesnt know anything about renovations can use
than to get the stuff yourself.

So tell the "friend" you need his help to pick up the materials, and remind him to bring enough money to pay for them.

Makes more sense to ask for the money up front and given him back what is left over.

If he for some reason can't do that let him know you'll be happy to help him whenever the money is available.