Bump

You might have better luck posting this in the flooring forum.

My house is the same way. It has to do with the installation. You can't use the nailer and pound the hardwoods in because the wall is too close so they use a prybar to get the tongue and groove together. The tongue and groove isn't pounded together as much so you have a space.

Thanks- Can something be done to fix it do you know?

You can expect oak to swell and shrink by about 1% with a seasonal swing between say 20 and 80% humidity. So for a 10 ft wide floor that could be as much as 1.2 inches. Whether it shows up spread across many joints or in only a couple places seems to be a bit random in the floors I've installed--but I'm not a pro. The best (and perhaps only) solution is to control humidity to avoid such huge changes, or use an engineered flooring product.

What kind of wood is it? Solid or engineered?

You could have them cut out those pieces and redo? The baseboard would have to come off as well but it is really not a big deal to fix if it really bothers you. The last board in the room has to have the protruding groove cut off so the last board is slipped in place and then face nailed. You could have them redo if you have extra board but like the above response explains...wood does shrink and swell so you may want to see how it looks in the summer before deciding to fix.

I don't even see any face nails in your photo so maybe that accounts for the wobble which is not normal. Maybe they forgot to nail it in from above altogether? I have a few boards that I didn't have the guys face nail in so I could rip out the tile next to it and those don't move at all even without nails.

Not good. If my oak hardwood did that, they would be fixing it and fixing it correctly. My hardwood was just installed last August and certainly isn't gapped anywhere like that.

Installed 3/4"x4" oak myself last August and there is almost no gaps from shrinkage even in a 20'x24' room. Could be I'm that good :) or could be the steam radiators keep the humidity up.