I have a wooden garden workshop with waterproof lining and insulation
inside.The inside lining is 6mm MDF. Is it acceptable to mount a 13A
dual socket using flush mount plasterboard box into the inside MDF.
What is minimum gripping thickness for these plasterboard boxes as
plasterboard is normally considerably thicker than my MDF. All the
specs I can find give a maximum thickness but have not been able to
find a minimum.
Thanks for any help/comments
Alan

"alanw"  wrote in message 
news:1126076904.437119.196120@g14g2000cwa.googlegroups.com...

>I have a wooden garden workshop with waterproof lining and insulation
> inside.The inside lining is 6mm MDF. Is it acceptable to mount a 13A
> dual socket using flush mount plasterboard box into the inside MDF.
> What is minimum gripping thickness for these plasterboard boxes as
> plasterboard is normally considerably thicker than my MDF. All the
> specs I can find give a maximum thickness but have not been able to
> find a minimum.
> Thanks for any help/comments
> Alan
>


Provided that the MDF lining is strong enough to withstand a plug being 
pulled out of a socket then go ahead and use a dryliner (plasterboard) 
backbox.

6mm MDF is probably too thin to allow the dryliner backbox lugs to grip 
tightly so just increase the depth of the MDF where the lugs fit by glueing 
a strip of say 60mm*20mm*6mm behind your MDF liner.

Adam

Adam
thank you for your advice
Alan

Another question now comes to my mind, does the cable feeding the
socket need to be in some protective tubing. I plan to run them
vertically to join into an existing ring, (effectively extending the
ring). The socket will be more than 150mm from a corner but cable will
be vertical above socket. Is it still allowable to have vertical
cabling above a socket without additional protection ?. Also I seem to
remember some restrictions apply to "thin walls". Would a shed wall
with outside shiplap, waterproof lining on a 2x2 frame with the MDF
cladding on inside be considered a thin wall. If so what special
protection would be needed to comply with regulations.

Thanks for any help/guidance.
Alan

"alanw"  wrote in message 
news:1126254322.849915.83050@f14g2000cwb.googlegroups.com...

> Another question now comes to my mind, does the cable feeding the
> socket need to be in some protective tubing. I plan to run them
> vertically to join into an existing ring, (effectively extending the
> ring). The socket will be more than 150mm from a corner but cable will
> be vertical above socket. Is it still allowable to have vertical
> cabling above a socket without additional protection ?. Also I seem to
> remember some restrictions apply to "thin walls". Would a shed wall
> with outside shiplap, waterproof lining on a 2x2 frame with the MDF
> cladding on inside be considered a thin wall. If so what special
> protection would be needed to comply with regulations.
>
> Thanks for any help/guidance.
> Alan
>

Cables laid vertically (either from above, below or both) to sockets with no 
mechanical protection is the normal way to lay cables to sockets in houses, 
although kitchen sockets frequently run horizontally between sockets.

The "thin walls" regulation is related to walls of less than 10cm. This 
assumes that on a thin wall with obvious access to both sides of the wall 
(ie a door in the thin wall) then cables may be run on either side of the 
wall above, below or horizontal from the socket.

This is a case of where common sense rather than meeting the regs to the 
letter applies. If the cables are laid horizontally or vertically to the 
sockets in your shed you can look inside the shed door and and decide where 
not to drill into the shed from the outside.

Adam

Once again, thanks Adam for the advice.
Alan