Two Irish men renovating a house

Two Irish men renovating a house

Paddy is pulling up the floorboards and placing the nails into two piles.
Mick says "Paddy, why are ye puttin the nails in two piles?"
To which Paddy replies, "these ones I'm goin tae use again but those other ones are upside down"
Mick then says, "Paddy you eedjit, ye can use them for the ceiling!"