Replacing an outdoor fixture box properly

pick1e

I need to replace the box holding the flood lights on the side of my house. It's not under an eave and directly exposed to the sun and rain.

The box that is there now is a standard blue Carlon box inset so it is about flush with the vinyl siding. It's screwed into a wood support behind the sheathing. I guess this is OK as far as code but doesn't seem like a great idea- it's all brittle from the exposure, hence why I'm replacing it.

I was thinking I should put a cast metal weatherproof box there and then caulk the seam between the box and the siding, but then I'm concerned about the siding moving around with expansion and contraction and water going in anyway.

Is there a better way? Or should I just do that and check the caulk when I replace bulbs?

Also, so that I don't have to make the existing hole bigger, can I just cut off the surface-mount screw lugs on the outer edge of the box (to make it round) and drill through the back to screw it into the existing support? I just wasn't sure if modifying the box was a no-no.

Thanks!

joecaption

Not sure what you have now but go to Lowes and pick up one of these.
http://www.shopping.com/builders-edg...ing-block/info

Most often with the style I think you have, that box would have had a cover over it and the box it's self never have been exposted.

hawkeye11

Yes, I would definitely use a metal box on the outside of buildings. And yes, after the fixture is installed again, it's a good practice to caulk and seal the around the fixture where it meets the siding. (Your siding should not be expanding and contracting under any conditions, so that shouldn't be a problem)

As for the box itself, you can buy an octagon box without a side mount, so that you don't have to make any modifications. But if that's all you have, go ahead and give it a try, just don't damage the interior of the box or create any sharp areas that may damage the wires.

pick1e

oops sorry

joecaption

May want to take that suggestion with a grain of salt.
Plastic boxes are almost always used out side due to shock hazzard and rust.
As I think you already know vinyl siding has to move, if not it's going to buckle.
The siding block I suggested will give you a nice trim and the outlet box all in one and will allow the siding to move behind it. And no caulking needed.

pick1e

I know about those, but I always wondered how much good they do... In a driving rain where the rain is dripping down the siding onto that the outside of that block, what's to stop it from running down the edges and then behind the siding at the bottom? Seems like you'd want to caulk that gap anyway to prevent that from happening?

joecaption

Vinyl siding always leaks, look at the bottom of the panels, there's drain holes.
That why they put Tyvec behind the siding.
The cover is suppost to have a rubber gaskit behind it to seal the outlet.
Your trying to over think this one.
Caulk behind it if you want it's not going to do any harm.

pick1e

Guiltyyyyyy!

I just want to do it right. Thanks for the suggestions.