a nice durable light flooring to lighten up the home.

https://www.wayfair.com/home-improvement/pdp/encore-surfaces-windsor-versailles-pattern-travertine-look-porcelain-tile-ecsr1514.html?piid=98825893

There's nothing wrong with the sun room except the yellow wall paint. I would select one of the tones from the slate floor and use that on the walls to HIGHLIGHT THE VIEW THROUGH THE WINDOWS.

The slate on the floor will keep the room cool in the summer and hold the heat in the winter. It was an excellent selection. Also will minimize any soil from the outdoors.

Once you select an area rug for to establish the seating area you won't even notice the slate anymore.

Make sure you create a very liveable space for this great area.

Keep the pine floors. Find out about adding another layer of finish so you can keep,them looking nice. I agree with Beverly that slate is practical and a big rug covers any floors we don’t like. Make it two matching rugs if that covers them better. Then add great wicker furniture and no one will notice the floors, including you.
My farmhouse has an ugly concrete porch and I did exactly this.

My problem with this slate is that is very hard to clean. Way too many grooves. But I'm more concerned about choosing between wood and tile through the rest of the house. asking

That is a nice slate blue paint.

Once the slate is cleaned and an area rug placed, you'll only require some spot cleaning.

Even with white walls for the Country French Esthetic I would also keep the pine floors, however I would stain them darker than the ceiling. I see pine floors that are centuries old in British homes and they just keep refinishing them. Now there are much better sealing products that can be applied to help you maintain their appearance. Check out BONO products.

I like a gray slate or stone tile look for rooms with lots of wood. I see how you may not love the slate floor in the sunroom, but it’s useful and I would keep it for now.

You need gauged slate no edges sticking up like you have now and installed in a mortar bed is best . Have you thought about vinyl tile I have 3 huge dogs they have not been able to ruin my vinyl plank in a total of 18 years not always the same 3 dogs. I do love slate but pretty hard on knees and backs for humans and dogs when all through a home .

Have you spoke to a wood floor specialist? I would find out if the floors can get a tough finish that is durable for a young family. Historic homes have wood floors that have lasted and I’m sure they also had rowdy children with no thought for “mom’s floors”.

Slate is perfect for a sunroom. It’s not hard to keep clean. Just sponge mop. Again, ask the slate floor,specialist about finishes that are better for family life. And rugs in a sunroom make sense with your decor choices, so those will help preserve the slate.

I had a floor specialist out and he would not repair the floors as he truly believed they were not salvageable and I wouldn't be happy with the finished product.

Well there are flooring guys and then there are flooring guys. It depends on where you live and if you expect the floor to look like plastic or if you are prepared to accept a vintage appearance. I don't believe you posted any images of the pine floors.

Since you have disagreed with most advice given you you on the forum, then it's best you do whatever you want to do.

I think you should at least get one more opinion on the floor refinish some guys just do not want the work. I do agree you might not want our advice but take it or leave it.

Jill, ask another floor guy. I would never take one person’s opinion. You need more than one for this floor. I would try to salvage it.

^1000% - our pro feathered in new wood (where needed) with the old and you could never tell

fwiw you likely won’t want to lay new flooring over old, messes up door clearances etc and can cause the new flooring to fail over time

Get at least three opinions from floor pros. And post pics here of the areas that are in bad shape. It looks like you have beautiful wide plank pine. I'd think long and hard about ripping them out.

I would get rid of the slate in your sunroom. Cleaning those grooves seems like a major PITA. Sure, you can get it refinished, but the texture is still trapping lots of dirt on a regular basis on a working farm. I'd just get a large tile floor that is slate colored. It will wear well, be easy to clean, and you can cover whatever part of it you want -- or not.

If you choose new porcelain tile throughout, take a couple tablespoons of dirt from outside your door with you when you pick up sample tiles. The most practical tile color is the same color as your farm's dirt.

A couple of robot vacuums may help with the farm dust and pet hair. Farm dust goes everywhere, especially when the windows are open and the wind is blowing a nice breeze. You may have to run robo vacs every day.

I agree with the above comments about getting a couple more wood flooring refinishers out to take a look at the pine flooring. Sometimes wood is just completely worn down so it is too thin to refinish, but often it can be refinished with sanding and three coats of polyurethane.

So there are huge gaps all over the house. Filling them wasn't recommended due to their size and continued expansion/shrinking. I asked about adding wood strips and it was impractical due to the large amount. The home was a DIY build and the (very experienced and respected) floor guy suspected that they used one too few planks the entire length of the house.

Oh, and the big one is that the wide gaps have broken down the tongue and grooves.

Great photos that show the poor condition. You've talked to the refinisher about the classic solutions already. I can see why you want a new floor.

I read about a homeowner who removed the planks, flipped them over, sanded them down and finished them. It was a horrendous amount of work to save the floor. If you remove the boards, some renovator may want them to reuse elsewhere.

Have you talked to a floor restorer instead of a floor refinisher? Those are two different skills. A restorer repairs floors and refinishes them. I'd get at least three people in here to look at your floors and make sure one does the primary bulk of their work in restoration. I presume that the people you know who loved this guy and highly recommended him had floors in better condition than yours that just needed refinishing.

I had 170 year old heart pine floors in much worse condition then yours. I could not stand to rip them out. I used stain pen to color in the areas where the top layer had come off, like in your second picture. People before me used an old marine boat deck trick of dipping rope into shelack and filling the floor board gaps with it. It was beautiful.

I don't get that these floors are that old or precious to you and you likely don't want the labor of love approach. A pine floor has so much character, I'm curious why you want to go with white oak instead of new pine? Because it is harder?

If you don’t want to keep the pine or slate no matter how it’s finished you won’t like it and that’s totally fine! It is your home. I do not know how easy it will be to put new flooring on top of this existing line though. Did the flooring guy address that?

Another addition about the pine: I have three people tell me the grade is poor. It's not heart of pine or even a high grade pine.

The floor runs the length of the house, under the walls so I've been told the best way to address that is to sand for levelness, address any soft spots, and then lay floor across the top in the perpendicular way.

I think one more piece of info could help: this house was DIY built in 2001. It's not an old house. So the floors are not the seasoned pine people might think that it is.