Why do you need two plastic washers when fitting a tap?

[mrbodge]

The guy at the shed and one of my DIY books says you need two plastic washers when fitting a tap.

I fitted a tap as described, one plastic washer between tap and top of sink and another between back nut and bottom of sink.

The tap would NOT sit still. I could not stop it moving left or right.

In the end I took off the top plastic washer (between tap and sink top) and did up again. Now the tap stays solid and doesn't move at all. I dumped a lot of water on the tap and not a drop leaked through to the tail (presume the backnut washer got it all).

So why are we supposed to do this? And if I am committing a sin against construction by omitting the top washer what should I do to stop the tap spinning?

 

[neds]

Stop you damaging the ceramic but yeah its to form a seal however I never use it that way. A small bit of cured silicone for me.

 

[Homesafe]

Stop you damaging the ceramic but yeah its to form a seal however I never use it that way. A small bit of cured silicone for me.

Proper cowboy

 

[Paul Barker]

In England we put a rubber washer on the top so that the tap body does not turn but grips and a nylon wahser underneath for the back nut to slip on, so that the force of turning the nut is converted to pull down force on the tap without the unwanted side effect of rotating the tap. After a tap is correctly fitted in this way it will not rotate and it will be well held.

Any manufacturer that does not understand this process and so does not supply the correct materials is worth avoiding no matter how pleasing to the eye their product.

The scenario op suggests sounds like a nightmare for a real plumber in which custard has bougfht own tap on ebay because it looks pretty and is cheap, but is not fit for purpose.

 

[mrbodge]

In England we put a rubber washer on the top

Nobody told Readers Digest or B & Q. They both said use the plastic.

 

[mrbodge]

Stop you damaging the ceramic but yeah its to form a seal however I never use it that way. A small bit of cured silicone for me.

Stop you damaging the ceramic but yeah its to form a seal however I never use it that way. A small bit of cured silicone for me.

Proper cowboy

What silicone is the best to use