[dunny19]

should be interesting i think this one!

[HolmansUKLTD]

Apart from there has been about 27 polls before about pre-vaccing

[Londoner]

I know they all say we should pre vac but nobody can really tell me why?
if we tell the customers(because its true!) that a vacuum cleaner can't clean deep down.
Why do we waste our time doing just that?

The water in the tank and the end of a clean more than proves that it hasn't made any difference at all.

If I have a top of the range HWE with massive suction to suck the dirt right out of the carpet. What can a weeny little vac do in comparison?

I would be interested to hear what the other guys think.
I have long suspected that its just a habit, like brushing your teeth before you go to bed. You were always told to do it and now it feels wrong if you don't.

I vote its a waste of time

[Dynafoam]

Vince,

You are way off beam mate.

I have written extensively on this subject, most recently in the thread "i bought a Sebo..........."

What the "weeny little vac" is doing is removing dust before it becomes mud and fluff/hair, much of which your HWE would leave behind.

You were always told to do it and now it feels wrong if you don't.  

I was never told to do it because when I started cleaning carpets I did not even know weather carper cleaners existed - I determined logicaly that it was the best approach and then put the theory to the test.nearly forty years experience have convinced me that the theory was correct. Many others have arrived independantly, at the conclusion.

John.

[cleanmac]

A proper prevac on comm. gluedown is the crucial step to obtaining satisfactory results,their is a wealth of practical and theoretical information available confirming this.One pilelifter manufacturer recommends;20 to 30 passes over the same area with a vacuum,then use the pilelifter in two directions after that vacuum area again with a minimum of four passes.OTT you may think but the amount of dry dirt removed,on a restorative clean, employing this method is staggering.

We had recently  the oppertunity to clean 30sq meters of tight low level loop nylon carpettiles,it had been TM-ed  only weeks previously by a different company ,all the traffic areas had wicked back badly.
We started with empty bags in the vacuums and removed over 2kg of dry dirt!
Extraction was done at 135psi  and no wick back,very happy customer indeed.

QED as the Romans said.

David