Post your favourite "Muldoons"

[Malthus]

Some explaination is in order - a "Muldoon" is a neologism a friend of mine invented to describe a lurking home improvement nightmare created by the person who owned your house before you, which you only discovered after you bought the place.

It isn't something merely shoddily done, or a problem sneakily concealed; it is something done in defiance of all logic or reason (or merely with a staggering lack of foresight).

My favorite example: we have hot water heating in our house, and the previous owners had lovingly made a radiator cover for the radiator in the living room - and it looked very nice, quite suited the room's decor.

However, when we started the furnace up in the first winter, we discovered a bit of a problem: there was simply no way to access the radiator to bleed it. There was no access at all.

At first I simply could not believe it - I kept looking for some hidden panel or other which would access the valve. Eventually I had to give up, drill out the screw-heads (they were covered in wood-filler), and undo the whole thing. There was no hidden panel. Which was odd, since they clearly had built the thing years ago - they simply never bled the valve.

What are your examples?

[BTW the term "Muldoon" comes from the last name of the previous owner of my friend's house - no offence to those with that name out there, but somehow it seems to work and has caught on in my circle. ]