Old floorboards. What to do?

[MasterGland]

Hello. I am currently renovating my house. It is grade 2 listed and parts of it are 450 years old. There are 3 bedrooms upstairs and each has exposed floorboards. A lot of the boards are very old, some 12 inches wide and made of oak. I suspect some are several hundred years old. However, some have been part-replaced over the years, possibly as a result of recurrent woodworm, and so there is a patchwork of pine tongue and groove infill in done areas. I don't know what to do. The floors are warped and not level, but that is to be expected in a house of this age. Some of the gaps between the boards are as wide as 2cm in places. Has anyone had similar floors restored? I thought about just putting carpet over them but I would have to fill in the gaps first, and I feel like that would be detrimental to the floor. Advice? Please?

If it's listed you should do as little as possible to maintain the historical integrity of an amazing building. I'd get a nice rug or three to cover the worst bits. As they're bedrooms, traffic is not likely to be heavy.

Do you want to fix up the floors - ie try to match the old wood a bit better, or do you not mind the mixture? Sanding and oiling/varnishing would make it look beautiful and you could perhaps stain the pine to fit in. We had a hall floor fixed up for sanding and they used some old floorboards to patch really badly broken boards and cut thin strips of wood to patch in holes between boards too, and used some filler in places too and it looks amazing, especially when you consider the mess it was to start with. I like the sound of original oak - ours was just pine.
On the other hand, if you do want carpets, I think they just put a layer of thin plywood over them and screw it down so there are no bumps.

You probably need to inform building control,

Once they reopen find your local reclamation yard and have a look at what they have to match.

I'd be very careful and wary of what is beneath. Are you sure you don't have woodworm?

I was thinking about removing the areas of pine and sourcing reclaimed oak boards for a more uniform look. But on further investigation, I think even the pine bits might be perhaps victorian. The large gaps bother me as you can't clean down there and they are also very creaky! Perhaps just nice rugs then? I don't want to damage anything, but don't think it is very livable at the minute?

I've just sold my 172 year old listed grade II, and had to have a plumber round before I sold. I was really shocked he jemmied up a floorboard really roughly, and it split the wood in half. I went to our local timber merchant and he said he couldn't get a replacement as the width/grade of wood wasn't available nowadays, and I'd have to go to a salvage yard. Our nearest salvage yard is about 50 miles away so I had to buy plates and bodge it back together.

We did have all the floors checked for woodworm, and it was all deemed historical and not active.

You'll need Listed Building consent to do any structural work with them. The advice is to retain and repair. I'd get a specialist in. Maybe you can lift and close the gaps, getting reclaimed boards as you say to replace the later ones?

Yes, Im aware I would need consent. I'm dreading that hit as the council have been a nightmare with other works. I'm starting to think this could end up being quite expensive. I'm so torn, because I don't want to damage anything inadvertently.

@Salome61

I've just sold my 172 year old listed grade II, and had to have a plumber round before I sold. I was really shocked he jemmied up a floorboard really roughly, and it split the wood in half. I went to our local timber merchant and he said he couldn't get a replacement as the width/grade of wood wasn't available nowadays, and I'd have to go to a salvage yard. Our nearest salvage yard is about 50 miles away so I had to buy plates and bodge it back together.

Oh dear. This is the sort of thing I'm worried about.