Weatherproof Junction Boxes

[Ianm]

Can anyone give me a tip on the best way of fixing / sealing a weatherproof box to a wall (externally, but in a covered space). I assume that the simplest thing to do is to coat the screw that fixes the box to the wall with a silicon sealant. Is that correct? Is there any particular sealant to use? Any other ways of doing this?

Thanks
Ian

 

[RF Lighting]

What are you wanting to do?

Is the box going to be installed to house a joint?

What size and sort of box are you wanting to use?

 

[Qedelec]

I always put a ring of silicone sealant around the screw hole on the outside of the box before screwing to the wall. Than for good measure I add a dollop on the screw. Works for me.

 

[Lectrician]

Take the sealing washer off of a hex self drilling sheet roofing screw......or use that screw.

 

[Ianm]

Thanks Qedelec.

RF Lighting. The boxes are (1) to reduce an armoured cable to a 1.5mm flex and (2) seperately mount a wireless switching box which will take in 3 x 1.5mm flex through w/proof glands. All will be sited externally under a plywood and tarp cover, but obviously be subject to damp. All boxes are IP66 rated.

 

[Taylortwocities]

And drill a drain hole in the bottom of the box, just in case there is any ingress. Many boxes have a handy area for this marked "drain".

Bit of a giveaway, really.

 

[Ianm]

Thanks to all - good advice

 

[RF Lighting]

I was thinking if you use a gewiss box the screw holes are sealed from the innards of the box when the lid is on, so you do not need to add any sealant

A tight screw will seal its self well enough to the back of the box anyway. Providing you drill a drain hole there should be no problems.

 

[Lectrician]

Many sizes of gewiss box come with a tight fitting cover to go over the raised screw holes internal to the enclosure. Particularly 're-badged' gewiss boxes such as the 'primeline' range.

 

[plugwash]

the drain hole is the most important bit. Stopping a small ammount water getting in is virtually impossible and you really don't want to get into the siuation where once water gets in it never gets out.

 

[breezer]

I had condensation in one of mine, drilled 2 tiny holes in the bottom, no problem since