Confused about residential wall construction (USA)

[defspace]

Okay, I know someone here will know the answer to my question.

I'm looking to hang some shelves/cabinets on the interior of an exterior wall. That is to say the cabinets would be mounted inside the house but the other side of the wall faces the street. For the life of me, I cannot locate the studs. The stud finder doesn't pick up anything. The only studs I can positively locate on that wall are on either side of a window. I used a strong magnet to locate the screws used to fix the dry wall to the studs. One vertical row of screws was 16" from a corner, another row 32" from the first row - surely studs! Nope, I drill through 1/2" of drywall and then another 1/2" of plywood or some other harder material.

What's going on? Is there plywood on the studs with drywall over the plywood? Any clue how I can locate studs with another layer of material in the way?

I can locate studs just fine on interior walls. 2009 construction. No additions or major renovations.

[thollandpe]

What are you seeing for insulation? There are Structural Insulated Panel (SIP) walls, which are a foam sandwich with OSB skins, usually inside and out.
https://www.sips.org/what-are-sips
https://innovapanel.com/about-us-2/h...f-sips-panels/

[defspace]

What are you seeing for insulation? There are Structural Insulated Panel (SIP) walls, which are a foam sandwich with OSB skins, usually inside and out.
https://www.sips.org/what-are-sips
https://innovapanel.com/about-us-2/h...f-sips-panels/

I'm not sure what the insulation situation is. It definitely feels like there's OSB (or similar) behind the drywall. But if SIPs add any additional cost, it wasn't done.

[defspace]

I didn't know what SIPs were this morning and now I know I live inside them. Funny. I pulled off a plumbing access panel, drilled a 0.5" hole - sure enough OSB over foam. This explains it. Thanks Todd!

[thollandpe]

I didn't know what SIPs were this morning and now I know I live inside them. Funny. I pulled off a plumbing access panel, drilled a 0.5" hole - sure enough OSB over foam. This explains it. Thanks Todd!

Woohoo—monocoque composite structure, baby!

And you can hang your shit wherever you want to hang your shit. It’s a nice system, but like anything and everything, if it’s done right.

PS Chapeau to your stud finder.

[j44ke]

Guy who was working on a neighbor’s house in the Hamptons showed me his wiring technique for SIPS. At least vertical wiring. Cut a hole at the top of the wall and hole where the light switch and/or outlet was going. Cut out some foam from each spot. In the lower spot put a metal cup. In the upper hole drop a large red-hot (as in heated with a torch) ball bearing. Bearing melts the foam and lands in the cup (assuming you got the alignment right.

Pretty trick. Didn’t see how he did horizontal routing though.

[dashDustin]

hot damn. @defspace, how old is your house? and any idea who the builder was?