A friend is building a new house. He is going to use (and already has them) the 4X8 panels made of 6" of white styrofoam sandwiched between OSB board. There are several ways to create the holes/chases needed for the wiring, I am not familiar with them yet. Not sure, but guess sheetrock must apply directly to the OSB on the inside...no studs except at the edges of each panel. Anyone ever had any experience with this or similar? I will have to investigate how boxes will mount, and hope I can use plastic, maybe screw thru the "ears" and thru to the OSB. I dread the thought of using steel old work boxes. I use to wire log homes, and this promises to be as unorthodox and weird. Gotta love the conventional "stick-built" homes.
If I was going to build a heavily insulated home not sure I'd want chases made in the insulation which may defeat the purpose of the heavy insulation?? Maybe they strap the inside OSB for the sheetrock??
#71615 - 11/02/0608:07 AMRe: House built of pre-fab panels
Saw one quick video segment on his computer which showed strapping on the outside OSB on which siding was installed, NM was run out thru and traveled in this void. With the log home we would wait til the bottom course of logs was in, then drill with a long ship auger bit at an angle back into the sill area of the basement. Then the carpenters would drill each successive log precisely so the holes would line up up to the receptacle. Switches that were on outside walls were fed up thru the space next to the doors prior to trim boards and drilled sideways to a drilled/chiseled out box hole. Recetacles boxes were drilled/chiseled out later at the location of the existing hole-chase. Some of these techniques will have to be modified and used...mention was made of a heated up plumb-bob being allowed to melt its way down thru the styro. Sounds like fun. I will check out the manufacturer's website.
#71617 - 11/02/0610:27 AMRe: House built of pre-fab panels
I do believe a skill saw is involved to cut a chase in the face of the OSB. Clips would hold the cable in place. The sheetrock would then span the cable openings. Old-work boxes would be face screwed to the OSB, extending out to the depth of the sheetrock.
#71618 - 11/02/0601:46 PMRe: House built of pre-fab panels
These are commonly referred to as SIP buildings (structurally insulated panel). They typically come with a wire chase that runs through the panel horizontally at standard outlet height. The carpenter sometimes has a 110v rod shaped heating element that is used for making a chase where there isn't one such as for switch runs etc. This all varies based on SIP manufacturer so you'll have to check with them. Usually if the SIP panel is for a residence then one side will be OSB and the other side will be sheetrock so you have to use cut in boxes.
#71619 - 11/02/0609:17 PMRe: House built of pre-fab panels
I do believe a skill saw is involved to cut a chase in the face of the OSB.
I wouldn't do that unless the manufacturer specifically says to do so. Typically, that OSB is the structural part of the system. If you make a long cut in the OSB, you are creating a large weak area that just might cause a structural collapse.
#71620 - 11/02/0610:21 PMRe: House built of pre-fab panels
I have worked on these type of homes before. most of the time there is a 1" chase through the panel every 24" horizontally and every 48" vertically. I the assemblers of the panels line them up right you will at least be able to wire up each wall easilly and then move from wall to wall through the floor or the ceiling. a zip tool or jigsaw works well to cut the boxes out (which you may want to locate at 24" to the top) and I like to use plastic boxes with 'ears'. Wiring a house like this is a lot like doing a log home so I would make sure to account for the labor intensive aspects of cutting notches, boxes, etc. Good Luck!