Garage Subpanel

I built and wired my last garage in Virginia, but now am stationed/living in CA (Yolo County), and bought a house. New house has an outdoor panel (WTF?) on the complete opposite side of the house as the garage. I'd like to put a 50a/240v sub panel in the garage to run my electric brewery, air compressor, and welder.

I'm having a bit of a tough time getting electricians to even come out to give me a quote. Sooo... I think I can do it myself- couple questions.

Can I pull 6/3 NM-B (romex) through galvanized conduit, or do I need 6/3 U/F? If U/F can I run it without conduit on the outside of the house to the entry point in the attic? Was considering running conduit up the side of the house from the panel into the attic and then running it bare across the attic to the garage. This seems straightforward enough, but it also seems like some people don't think you can pull that through conduit.

I've got some experience with wiring a 240 sub panel, but this is a slightly different case and thought there might be some good advice.

I see a lot of outdoor panels when I watch the hgtv remodeling shows. That's very weird for somebody in the Northeast.

I can't comment on the cabling part, but we put in a 50 amp panel in my garage over the course of a decade (yeah, we work slow). The best thing I did was when we hooked it up to the main house 200 amp panel, we used one big honkin' breaker to connect the garage circuit. When I want to work in the garage, I just flip the breaker and power up the garage (main panel is by the basement stairs, super convenient). When I'm done working, the breaker goes off. I only have power to the garage when I'm working in it. Gives me peace of mind knowing the wires are cold in case anything happens.

The UF cable should be fine, that's what it was like all over Placer county when I lived out there. Usually tucked up out of the way under the eve of the roof.

Hell, I used UF just to run through the block wall when I put my sub panel in my garage here.

In Las Vegas, pretty much 100% of residential breaker panels are outdoors. When weather is not an issue, it makes sense from a fire safety standpoint. If you have a fire, you can turn off all the electricity in the house from outside the house.

If the conduit is on the outside of the house, the wire inside it needs to be rated for use in wet areas. That means NM-B/Romex is not allowed but UF is OK. However, if you're running the wire in conduit there's no good reason to use UF - it's stiff as heck so would be very difficult to pull through the conduit, and also you'd have to size the conduit large enough to accommodate the UF as well as meet code requirements. You'll be better off running individual THWN wires, they'll be a lot easier to pull and probably cost less.

If you go through the attic, you may also need to look at derating the wire ampacity because of high temperatures. I don't know how hot it gets in your area but attics in general are hot anyway.

Well, I would say that it gets hot as berkeley- Sacramento valley has a hundred days of triple digit weather potentially. So would likely want to de-rate the wire. This is far more complicated than I like.... thank you for all the assist. $325 for 125' 6/3 UF and I think I've found THWN for .44/ft, so with four total conductors I think I'm under $225... add some for conduit, and it will about equal the UF. It's a matter of whether I get up the outside wall into the attic, and back down a wall, or try to bury it under the front walk (about 6' under a walkway that I will likely replace).