Post pics! Because this is going to look like a sack of shit.

If it's an exterior wall it could be frozen based on your geography. Had to run a space heater in our powderoom overnight in Xmas Eve to thaw it (Eastern PA/high of 7). Woke up to a full tank.

To add, drain the system from a lower location, like a hose bib, or downstairs sink.

This would also be my guess.

Usually there's blueprints that come with the house with concepts of what could happen in the basement. That would also help confirm if you happen to have them.

You recently bought the house, and hopefully got it inspected beforehand. What does the inspection report say about the plumbing?

Do you have a crawlspace or basement? If this was me I would plan on removing back to below the floor and possibly stubbing up inside the wall.

Floor valves like this get exposed to all kinds of bathroom cleaners and toilet splash and will corrode faster.

It's not really corrosion so much as mineral buildup from the water, so if the pipe is original to the house the chances are pretty high that its blocked up pretty good. I'm not sure if there is a roto-rooter type action you can do to clear that up, or if you just have to replace all the pipes over time.

99%

Had this exact issue recently. Plumber cost $500 to change out valve in metro Atlanta.

Everyone talking about the gap but nothing about the huge problem you now have.

Aluminum doors are a big ole 0 for insulation. They let cold and heat through them like they arent even there. You need to look into some insulation boards for them and install. That will definitely help with the cold in the garage.

You can try replacing the flexible supply line first—I’ve had those become obstructed with god knows what I’m the past, making the toilet really slow to fill. But as others have said, don’t try to just replace the valve, you’ll need to replace some lengths of pipe as well. Looks like it may be galvanized, in which case you can screw some new pieces together or replace with copper or sharkbite. As for the floor, don’t worry too much about how to clean it, if it were me I’d just live with it until it’s time to replace. This bathroom likely needs to be redone!

If you are concerned about the visual gaps on either side, you can add trim pieces that extend past the gap, similar to door casing, except it fits to the inside of the jamb, not the outside.

Don’t listen to anyone telling you to cut or fix this with a new fitting. That pipe is very corroded and appears to have been wrapped to stop a pinhole leak. The rest of the pipe that isn’t visible is likely in just as bad shape and needs to be inspected. My money is on it being just as bad as the small portion we see.

It’s going to be more work, but you need to replace all of the pipe that is in this condition. If it’s not already leaking under the floor, it will be in the near future.

What are the chances of this pipe is corroded beyond what is visible?

But reddit told me "i can do this"

>shut the water off to the house

To clarify.

If you live near a major city, you might get some luck by doing a lot of comparison shopping from flooring wholesalers. My brother installed flooring that is sold for $12 a square foot, but was able to find it for $3.50 a square foot at a wholesaler. Good luck in your search!!

Shut water off. Cut the tape with a utility knife. Use two wrenches to remove the valve, one to hold the valve, the other to loosen the nut on both ends of the valve. It will be tight. Two wrenches are required to keep from twisting the pipe. After you remove the valve, clean the pipe with a piece of Emory cloth, then inspect. There may be a little copper ring over the pipe, it is part of the compression fitting on the supply end. If damaged, it looks like there is room to cut about 3/4” of the pipe off with a tubing cutter. Install new valve with compression fitting. Tighten well and test by turning water back on, slowly. You can do this!

At some point you may want to call in a professional, even just for an estimate and see what they say.

You likely going to need to pull up some flooring and replace the pipe which you probably should do, water damage can get expensive fast if not dealt with before it happens.

This is DIY friendly.

Thanks. That's a big help.

You can, but the idea of having a minimum 1/4 inch or 5mm is pretty standard practice, so you can insert 2 wedge shims, one per side to square your frame. Leaving a smaller gap leaves less room for shims and my result in a twisted frame if only 1 shim can be inserted.

Cool, so if I frame the rough aperture fairly square can I slim down that 5 mm each side because I know I'll have removed most of the error in the outer framing? I'll only have minimal tweaking to do I hope.

It's so shims can be inserted to make sure the door frame is vertical and plumb. Rough openings are exactly that, rough openings, and are rarely perfectly square and plumb. The gap and shims give you room to adjust it so your doorway is square

This is going to snowball on you