I will always check a shower, first of all to see if it works and also to check a few other things. For such a simple fitting, there's a surprising amount that can go wrong.

A couple of years ago, I was surveying a large and immaculate 20 year old bungalow and, no matter how hard I tried, I couldn't persuade the control knobs to move on the plumbed thermostatic shower mounted over the bath.

It transpired that when the owners moved into the house, as new, the husband tried the shower, just once, decided that he preferred a bath and it hadn't been used since! The internal workings were seized solid.

So what, you might think, but what happens when you move in, you try to turn it on and realise that it's not going to work. Plumbers don't come cheap and you could probably bank on a few hundred pounds for a new shower and the plumber to fit it.

Sorry, the plumber was the one whose actually banking in that case!

I was once in a very large house and checking the shower in a guest Bedroom which was the furthest room away from the combination central heating boiler. It took around 5 minutes for hot water to get to the shower head - this was a very long pipe run.

Just as the hot water came through, the not unattractive lady of the house burst into the Bathroom and said "I thought you were having a shower"!

To this day, I wonder if:

a) Her experience was that Surveyors tended to have showers in other peoples houses.

b) She considered me to be so good looking that she was planning to get in with me (unlikely). 

c) It was a humorous comment.

Answer 'a' could never be considered valid and as far as 'b' is concerned, the expression is "in my dreams"!

Seriously though, the majority of showers leak. Failed grouting and seals between tiling or other wall finishes and the shower tray base let water into the floor below.

If you are in a modern house with particle board sheet floors, these get wet and disintegrate. Floorboards will eventually rot.

Any stains on the ceiling to the room underneath the shower? - its leaking! How long has the leak been going on, are the floor joists now rotting, how much of the ceiling has to be taken down to deal with repairs?

Even a blocked shower drain, which is not uncommon, can mean taking the shower tray out, damaging tiles, fixing the problem and then putting everything back together again.

And what happens when you take the shower tray out and the base tiles and discover that the wall plaster or plasterboard has had it because the grouting failed because someone didn't use a waterproof grout and adhesive?

Here comes the plumber again, rubbing his hands together with glee as he contemplates your next bill.

Surveys warn you about this sort of thing. It's the Surveyors job not only to look at the surface, but to consider what is going on where you can't see it.