Plumbing – Leaking hose bib

As the comments have pointed out, that is a compression fitting and not a threaded fitting. Removing it should be relatively easy. Loosen the nut by holding the valve with one wrench and turning the nut with another. Once it is loose enough, the valve should just pull off the pipe.

You will have to examine the exposed portion of pipe once you remove the valve to determine if you can re-use the pipe and valve as-is or if you need to cut it inside and install a new stub that you can then install a new valve on. I doubt you will be able to re-use it (its damaged already, hence the leak), so in all likelihood, you will have to replace it. If you do replace it, get a ball valve (1/4 turn) as they are more reliable and easier to operate.

Hopefuly you have an inside shutoff valve for this. If you don't, you will want to ensure you have everything you need before starting this project as the water to your house will be off. If you do have a shutoff then just close it and you can take as much time as you'd like.

Note that you should not use pipe tape or dope on compressing fittings.

So what I did took a couple of weekends and the acquisition of new tools and skills, but I figured it out to my satisfaction.

I did Steps 1 and 2 from my checklist above. For the spacer, I build a 3x5" box out of 3/8" plywood and scribed the edges to match the uneven cinder block. I used a rotary rasp bit on my drill to “carve” the box edges to my scribe lines. It took a couple of tries to get it to fit decently, but in the end it pushed out the flat box face away from the cinder block and just under the siding.

I painted it with the same outdoor masonry paint that we used to paint the cinderblocks, and applied caulk along the edge. Inside, I filled the gap between the block and the pipe with expanding spray foam.

Jack's answer is still a good one. I just preferred not to punch a new hole in the wall.