I renewed my acquaintance with the builders last week, a year and a half after I thought I had waved goodbye to them for good.

Those of you who were readers of the Ground Floor back then will remember that the arrival of the builders coincided with some tense moments in the family home as well as the introduction of a tranquilliser regime for the cat.

So you would think I'd have learned my lesson and would have steered clear of men with sledge-hammers for the foreseeable future.

But it was a case that replacing the staircase - which we really should have done at the time - needed to happen now, and so we threw open the door to the men with the reinforced boots and allowed them rip the house apart again.

Walking round a DIY store a few months ago, I came across a whole section on "replace your own staircase in three easy steps" complete with a picture of a smiling woman looking proudly at her newly installed creation, but even in my wildest dreams I didn't think that either the man or I were crazy enough or competent enough to have a go.

And, as I peered directly from the landing into my kitchen last week (a feat not normally possible), I was really glad that I'd called in the experts and got the job done properly.

As with all these things there are a few snags.

My wooden floor now looks a bit more weathered than it had done previously (thanks to the ministrations of the plasterers - the most skilled bunch of people I know but it's the filthiest task in the world); my thermostat has been replaced sideways on the wall (not that you'd notice until nothing comes on and you realise that it's not actually set to hot as you'd thought) and the newly plastered walls have to be repainted (another little job around the house for the man).

But by and large, Francie and the crew came up trumps again. And I couldn't help thinking that despite all the exhortations that we get to cut out the middle man, give it a go and do it ourselves - sometimes you have to accept that calling in the experts is the only thing to do.

All through the 1990s, Alan Greenspan was considered the financial expert that kept the American economy - and, as a consequence, the global economy - running like a well-oiled machine.

But since the implosion of the world's stock markets at the beginning of this century, Greenspan has faced ever-growing criticism of his handling of the markets by newer and more vocal experts and is being blamed in some quarters for both the tech-wreck bubble and its inevitable bursting.

He hit back at some of those critics last week in his speech to the Kansas Fed when he said that the only way to have curtailed the rise of the stock market (and don't forget he was concerned about it way back in 1996) was to have dramatically increased interest rates.

But the kind of sharp tightening that would have been necessary to do that job could have just as seriously damaged the economy.

A sharp and sudden rise in rates, the kind that would have stopped people piling in to speculative stocks, would also have killed off expansion in more mature companies that were prudently well run.

Nor did he think that lots of smaller increases would have done the trick either since he believes (rightly, I think) that moderate rate increases are ineffective in dampening stock prices over the long run.

Others thought Greenspan should have tightened the requirement for margin lending, which would have dampened speculation by making it more difficult for short-term investors to borrow to fuel their speculative habit.

It probably would have had a short-term impact, but bubbles take on a life of their own and, truth is, the momentum would still have continued because everyone believed in it so much.

Once the market ignored his "irrational exuberance" comment then there was never anything the Fed could do to slow things down. But nobody was listening to that expert opinion because other experts (who had vested interests in the rise and rise of markets) did not think the exuberance was irrational at all.

In the late 1990s everyone became an expert in financial markets. People I barely knew would give their opinion on stocks that I'd never even heard of and looked at me askance when they realised that I had not become a multi-millionaire trading telecoms. (I wish I had, obviously.)

Friends who worked in the technology sectors revealed their plans to retire in five years and tipped more stocks I'd never heard of to help me to turn off the Word programme forever.

And a few years later where are we left? Well, a bit like the house would be, I reckon, if I'd tried to rip out the stairs myself. There are gaping holes where companies like Enron and WorldCom used to be.

There are scratch marks and deeper scars on the psyches of everyone who ever had anything to do with stocks and shares.

The market's own thermostat isn't even replaced sideways, it's still hanging out of the wall waiting for someone to plaster it into place. And there are people walking around saying "never again" when it comes to expert advice.

The true advice did come from an expert. Alan Greenspan knew what he was talking about. In 1999 he testified that the Fed needed to focus on policies "to mitigate the fall-out when it occurs and hopefully ease the transition to the next expansion".

But like the enthusiast dazzled by the video showing you how easy it can be to "do it yourself", many of us plunged into areas about which we didn't have a clue after all.

And the video didn't have explanatory pictures for the things that could go wrong, only smiling faces of people who'd done it right.

The lesson is to choose your expert wisely.