@sonofsven:
The longest, most visible wall is the right hand wall in the living room which is about 25 feet from front to back.
The reason I ask about transitions is that the left-to-right distance in my house on the first floor is about 50 feet. I've read that you don't want more than 30 feet worth of it...presumably because then the linear expansion in that dimension might exceed the 1/4" expansion gap.
I agree I might have to remove the baseboard on the last wall to install the last piece, although I've seen videos on ways around even that which look like they should work.
Correct, I plan to leave the floor floating.
Understood about the T-style molding. If the product I want doesn't have transition strips (I'd prefer it does, but we'll see), then I could do that.
@Malcat:
Right - I won't be abutting the LVP to the baseboards. I'll be going under them approximately 1/4" in all directions (existing baseboards are 1/2" thick at the base, so 1/4" gap and 1/4" overlap).
As mentioned before, I'm fairly certain there is already a gap underneath the floorboards which I can slide the LVP under.
Thanks for the comment about UV fading, had not heard that before.
I put 836sq ft of stone core LVP in our basement this winter. It replaced worn out, cat pee stained carpet and ugly sheet lino. I don't understand how your plan to slide the planks under the baseboards will work. When you're installing it you need to maintain an even 1/4" gap between the plank and the wall. To do this you place spacers against the wall (or baseboard) and then the planks basically get hammered repeatedly against the spacers as you built out the floor. At the other end of the room you lay the last plank in place and then use the z-shaped install tool to pull the last row against the rest of the floor. If that last row is somehow under the baseboard (I don't understand how you'd do that anyway) you won't have room to stick the tool in the right spot. The only way I can think of to install the floor flush against the existing baseboards is to use glue down planks that don't use the click lock system. Those planks are just flush cut and don't have the tongue and groove edges that necessitate installing the planks at a specific angle.
If you want to use floating floor, you'll need to either remove and then reinstall the existing baseboards (which I'd recommend) or use some kind of 1/4 round to cover the gap. If you opt to remove the existing baseboards, make sure you can buy more of the same pattern before you start. It can be hard to remove them all cleanly without breaking any.
The longest possible run depends on the make and model of the flooring you buy. Commercial grades likely allow for longer runs, plus they should last longer and have better wear layers and warranties.
Other important things I learned that weren't covered on YouTube:
1. You can only score and snap boards if the cut line is more than 8" in (may depend on the exact flooring you buy). For shorter cuts I had to use my mitre saw. For rounded cuts or fiddly cuts, use a jigsaw. Buy lots of jigsaw blades because they wear out fast.
2. The boards are basically plastic so when you cut them with a saw you generate a ton of plastic sawdust. Put a tarp down so you can reduce the amount of this crap that ends up in the environment.
3. I wish I'd rented a table saw. I had to rip more boards than anticipated.
4. Removing the carpet was easy. Removing the lino was hard because you have to scrape the glue off the concrete floor before putting the new floor down. The only tool that worked for this was a 4" razor blade floor scraper. That part took days because I'm a wimpy office worker and scraping 4" strips takes forever.
5. If you want to put LVP in the bathroom, think about how you'll treat where it abuts the tub. Our basement bathroom is tiny so I was able to cheat a bit on the 1/4" gap rule. I installed it flush against the side of the tub, but left the normal 1/4" gap against the other 2 walls and also put a transition in the doorway (the 4th wall in this bathroom). The transition allows the floor enough room to expand so it won't buckle and the room is small enough that expansion should be minimal.
6. We had to remove and then reinstall the kitchen appliances so we could run the new floor under them.
7. The weird L-shaped closet in our basement bedroom was built on hangover Monday. It's not even remotely square.