Why apartments here block more than houses
Most of the flats along this coast were built with 40mm waste pipe and short, shallow falls. That is fine for water. It is not fine for anything that congeals, and it gives a blockage nowhere to sit except exactly where it shouldn’t.
Add the two things that make a Spanish apartment different — a lot of holiday lets with intermittent use, and hard water that leaves scale in the pipe — and you get a system that blocks more often than the equivalent flat in the UK.
The four things that actually cause it
Not the myth. The real ones, in the order Greg sees them:
Cooking fat. The single biggest cause of kitchen blockages. It leaves the pan as liquid and sets solid about a metre down the pipe. Nothing dissolves it again except mechanical cleaning.
Hair and soap. Shower traps fill with a mat of both. It builds slowly, then one day the shower is standing in an inch of water.
Wet wipes, even “flushable” ones. They don’t break down. They catch on the first rough joint and everything else piles up behind them.
Scale. The quiet one. Hard water narrows the pipe over years, so an apartment that drained fine for a decade suddenly can’t cope with a normal load.
Why chemical cleaner is usually the wrong answer
It’s the first thing people reach for, and on this coast it’s often the worst.
Caustic soda clears a grease blockage if it can reach it — but if the pipe is already partly closed by scale, it can’t. Worse, it sits in the trap and attacks the joint seals. Greg has replaced more than one trap that a bottle of drain cleaner finished off.
On an old installation, a pressure pump or drain rods clears the blockage and leaves the pipe intact. That’s the difference between fixing it and moving the problem.
What to do before you call
If it’s a single fixture, there’s a trap underneath it — a plastic U-bend you can usually unscrew by hand with a bucket under it. Empty that first. It costs nothing and clears a surprising share of shower and basin blockages.
If more than one fixture is slow, or water comes back up somewhere else, stop. That’s the stack or the main line, not a trap, and no amount of plunging will help. Send Greg a photo of what’s happening and which fixtures are affected; he’ll tell you whether it’s a rod job or something bigger.
The one thing worth doing
Don’t pour fat down the sink. Let it set in a container and bin it. That single habit prevents most of the kitchen blockages on this coast — everything else is a smaller share of the problem.
Greg clears drains from Calahonda across to Benalmádena and up to San Pedro. A typical blocked toilet or drain is in the region of €60–€75, excluding severe blockages, and he uses mechanical clearing rather than chemicals.
