Flush light switch problem

[AndyJay]

Hi.
I've just moved the living room light switch up the wall about 2ft. For some reason it was way too low.

I've purchased a flush light switch, but even with the plaster knocked off the wall, the light switch protrudes above the surounding plaster.

Do i need to chip away some of the brick? Why is the switch so deep? surely no one has plaster at this depth on their walls.

Hope someone can advise.

thanks
Andy

 

[andy]

Hi.
I've just moved the living room light switch up the wall about 2ft. For some reason it was way too low.

I've purchased a flush light switch, but even with the plaster knocked off the wall, the light switch protrudes above the surounding plaster.

Do i need to chip away some of the brick? Why is the switch so deep? surely no one has plaster at this depth on their walls.

Hope someone can advise.

thanks
Andy

what do you mean by 'flush'? pretty much every lightswitch protrudes from the wall. normally, a 16mm backbox will sit nicely against the brick unless the plaster is really thin

 

[ban-all-sheds]

If it protrudes above the plaster, and you have got the shallowest box you can, then obviously you need to chop out some of the brick, or make the plaster thicker.

And yes - I believe that 16mm is a typical plaster depth.

 

[AndyJay]

Thanks guys for getting back so quickly.
The back box i took out is about 16mm but the new light switch depth (not counting the bit that protrudes above the plaster) is about 24mm deep.

It's a new switch but is much deeper than the one it's replacing.

I wasn't sure if i should chip the brick away, but it seems that this is normal.

By the way, we're sitting in our living room eating our tea with just one plug in lamp for lighting (wife thinks it's romantic)

I will have to get chipping away in the morning.

Thanks again

Andy

 

[andy]

Thanks guys for getting back so quickly.
The back box i took out is about 16mm but the new light switch depth (not counting the bit that protrudes above the plaster) is about 24mm deep.

It's a new switch but is much deeper than the one it's replacing.

I wasn't sure if i should chip the brick away, but it seems that this is normal.

By the way, we're sitting in our living room eating our tea with just one plug in lamp for lighting (wife thinks it's romantic)

I will have to get chipping away in the morning.

Thanks again

Andy

24mm seems a bit OTT. anyway, taking a part outta the brick is normal. and you have to do that for sockets. i wonder what the plasterer would say if every1 used 25mm backboxes on brick for sockets....

 

[AndyJay]

i might even take it back to see if they a more shallow one. The one i got is a modern gold double dimmer switch.

andy

 

[Lectrician]

Dimmers do require a deeper box - typically a 25mm

 

[securespark]

Some manufacturers even recommend a 35mm box for double dimmers, not just for physical space to fit the thing in, but to allow air circulation for cooling. I have two double dimmers in my lounge, both on 35mm boxes.

Check the instructions to see what it says.

 

[AndyJay]

Hi all.....

I've sorted out the backbox, but now have a question regarding the wiring.

I have two double dimmer switches in the living room.

One double dimmer controls the wall lights and the main light(1) and the other double dimmer controls the main light(2) and also the main light(1). There are two main lights in the living room.

When the main light(1) is turned on by either dimmer switch they flicker badly.
I have raplaced one of the double dimmer switches with a normal (none) dimmer switch and the main light(1) works fine.

Is the problem caused by having two dimmer switches controling the main light(1)?

Does that make any sense?

If it is the case that two timmers cannot control the same light, is there a work round?

Hope someone can advise me

 

[Spark123]

You can't have two normal dimmer switches controlling the same light. You can have dimmer switch one end and normal two way switch at the other.

 

[AndyJay]

Thanks Spark123

I will change one of the dimmers for a normal switch one.
Just out of curiosity, why is it that two cannot be used?

Thanks again for the advise

Andy

 

[Spark123]

Just out of curiosity, why is it that two cannot be used?

AFAIK it is to do with the thyristor firing in each of the dimmer switches which clash.

 

[AndyJay]

Oh! - well i did ask

 

[Adam_151]

spark123 has it in a nutshell, for more information on how dimmers work, see here: http://www.epanorama.net/documents/lights/lightdimmer.html

You can just imagine what a mess of the wavefrom two dimmers trying to cut the waveform would make, they'll just throw each others timing out, and do god knows what

 

[AndyJay]

Thanks Adam_151

That link explains everything you need to know about dimmers - a little above my intelligence though

Thanks to all of you..
Andy