Many moons ago my dad & I refurbished a small terraced house. It wasn't until some time after lifting some floor boards, that an adjacent nailed floor board could be seen to be cleverly pined to a central heating 15mm copper pipe! It was an old fashioned floor board nail- wedge shaped. It had gone straight through and not leaked.
The moto being - put pipes though the middle of joists and not just under floor boards..
The moto being - put pipes though the middle of joists and not just under floor boards..