Exterior electrical with rainscreen?
Hi folks,
Probably a dumb question here, but when using a rainscreen with plywood strips, is there any special considerations for the outside electrical, like outlets and wall-mounted lights? I’m planning on mounting the lights on small squares of trim board (which is mounted on the furring strips) to give a nice flat surface (instead of on the hardiplank). In that case should the box just be attached to the trim board itself? Or use the normal method – attach to a stud, then use a ring to extend it to be flush with the outside of the trim? That’s quite an extension though, about 2″.
Thanks,
Todd
Replies
Its almost impossible to mount standard boxes flush with the rainscreen. Too little of the box is left to hit the studs. My electrician uses boxes with boots mounted to the wrap or paper and installs gasketted box extenders. The electrical supply shops all stock lots of them here now fo this very situation..
Or you can just hang the wire out of the sheathing and cut the box in after the wall is mostly done.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
We are in a bit of a bind up here. What's logical is not always what is accepted. To build any house but your own, you have to be a registered builder. To get registered you have to show you have New Home Warranty Insurance coverage, and they publish details and spec.s they want you to follow. Sometimes it's as though they own shares in Peel and Stick.
Hey Dan,So you'd attach the box to the trim board? That would be the easiest, but I'm not sure that it would pass muster around these parts. Can't ask either, since the inspectors are on strike. Thanks,
Todd
If the back of the wall is accessible you can install a bar and mount the box to that. Otherwise use an "old work" box from the front.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
F&T,
Thanks (again) for the ideas. I'll look around today. I stopped at a smaller supply place, they didn't know what I was talking about, so I'll try a bigger place, maybe Guillevin. I don't suppose that you remember the brand?
The
nation home warranty pdf
that you pointed me to before has some detailing for exterior boxes, uses a piece of EPDM to seal the box. I've never seen that type of box (with a flange) before, but I'll bring the page into the supply house.
Thanks,
Todd
No sorry I don't know the brand. I think he gets them at Westburne in Victoria. You might try there, although any time I've been in they treated me like dirt.
If you are in Vancouver, with all the building going on it shouldn't be too hard to find a site where they are siding and see what they use. Just a thought.
F&T, visiting a site is a good idea. Can't swing a cat without hitting construction here.While I've got your ear, do you have a place to get hot-dipped coil roofing nails? Sheesh, I owe you a beer for all this.Thanks,
Todd
Sorry, never used hd nails. Probably should, but I always just use the Bostich coils. I'm sure if they are around Sleggs could get them in for you.
Don't worry about the beer - just keep an eye out for threads where I need advice and help me out.
I'm in the process of installing just what your looking for. I can't find my stupid usb cable for my camera otherwise I'd give you a picture.
My electrician suggested using a piece of 5/4th ceader stock just larger than the box being used. Used a plunge router on the face so the box sat in the bock just a little bit. Ran the block thru a table saw with a dado blade so the siding fit in the groove. Using a lap siding
(Still looking for my usb cable)
Did the same for all the boxes from little outlets to the meter box
I misspoke, the block we used were 1 3/4 cedar. The one block is solid for mounting a box. The other is open in the middle so the electrical box sits inside for mounting a light
Hi Curley,Sorry, I'm a little thick today. The box doesn't come out flush with the outside of the block? Does that meet code? If it does sit flush, how do you attach the box?This is one of those things where I just need to see one installed and I'll realize how simple it (probably) is. When you get a chance to install it, can you grab a picture on the wall?Thanks,
Todd
Here's some pictures you wanted. The dado cut matches the fur strip. I can't claim to be an expert. The electirican and myself came up with the idea. We ran conduit and he needed to know what we were doing outside. The blocks are 1.75 " cedar and the dado matches the 1/2 in fur strips. The lap siding will slide in the dado
I misspoke earlier. The electical boxes sat flush and a hole drilled for the conduit
The light has the center cut out and the box sits in the hole. The outer lip flush with the block
I'm no expert, maybe someone else can give you good advice
Hey Curley,Thanks for the photos. I happened on a job site that had a bunch of light boxes in various states of being installed (didn't have my camera though). Their approach was similar to yours, except that there was furring strips behind the blocks, and the box was first attached to the strips. Then a piece of the trim board with an octagonal hole was placed over the box. It looked like the wire was just put through a hole in the sheathing.
Rain screnn and electical boxes
Hi , I was happy to see your post with an explaination and pictures of how your electrician installs lights for a rainscreen. I am going to print it and show it to my electrician today because we are trying to figure out this puzzle ourselves. I do not see the pictures that you posted in the thread though. Can you repost them? or are they in the phot gallery somewhere?
Thanks
Greetings
The photos in this thread and in many many others were lost when this forum changed their software. That was a giant loss as there is so much history just washed away.
Curley hasn't been here for a while, but if you were to click on the MEMBER button in the left column-under your name and do a search you might be able to send him a private message. If his email is still viable, he might get it.
Best of luck.
Edit: Here you go-
http://forums.finehomebuilding.com/members/curley
I mounted regualr surface mount exterior boxes on cedar "light blocks", with a hole drilled through the sheathing and light block for a piece of conduit that was threaded into the box.
One has to become inventive to use regular flush mount fixtures on a surface mount box, but I am extremely pleased with the air tightness, that a surface mount box provides.
A medium to large guy named Alan, not an ambiguous female....
NOT that there is anything wrong with that.