Do you have a hygrometer ? If so, what are you humidity readings vs time. If not, get one.

Ask your builder re recourse, all anyone else could do is speculate. Check your home warranty paperwork.

so what you are saying is this is NOT supposed to happen

If it was that big of gaps all over I would say it would not be normal. It is normal in the winter month for gaps to increase in general because the humidity in your house is lower and causes the wood to contract. Like Jim mentioned you need to check your humidity level. I usually try to keep my house around 40% in the winter. If this is the only large gap in the floor I would say don't worry about it and get a Blend-fil pencil to fill it to minimize appearance.

Your contract with the GC will tell you if you have recourse.

But here's the thing: YOUR humidity (ie. how the homeowner maintains indoor humidity) is YOUR responsibility. I know. This sucks. But it is part and parcel of being a good homeowner.

Indoor living conditions must be (to maintain hardwood flooring WARRANTY):

1. Consistent temperature between 55F - 80F for the entirety of the floors life

2. Consistent Relative Humidity Levels between 35%* - 60%*

2.a. The humidity should NOT swing more than +/-5% (ie. the window should be 45%-55%)

As mentioned above, you will NEED to take some humidity readings in your home. Especially in the rooms where the big gaps are happening.

You can purchase a hygrometer (that's what they are called) at HD for $35 each. You will then take DAILY readings (at the same time each day) for 2-4weeks.

**IF (and only IF) your readings are ABOVE 40% at all times during your documentation will you have a hope in Hades getting your GC to own this problem.

If your readings are low (35% is probably too low in winter...because the floors were probably installed at a more humid time) then you must ADD humidity to your home. Your HVAC system MUST HAVE a whole home humidifier. If it does not, you will need to add one.

If your readings are low and you DO NOT have a whole home humidifier you MIGHT have legal recourse against the GC. *Might. You could file a court motion stating that the GC KNOWINGLY built the home without the proper HVAC set up for your situation/location.

This works ONLY IF this was a tract home that you 'walked into' once it was partially built. If you started this from the ground up (ie. you bought the land and hired the GC and you OK'ed the plans) you won't have a leg to stand on.

I'm sorry this has happened. You need more moisture in your home. You need it very very quickly!

how do you keep your house at 40%? do you have a whole house humidifier?

That gap looks more like a combination of milling of the flooring and poor installation for not culling the board out at the time of installation. But you very well may have humidity issues as well.

We have a few cracks and it's was our own fault. We let the house get too dry. It's a new house and with using our wood stove it got down to around 25% humidity and that's when the cracks started. We now have 2 portable humidifiers we use to try to keep it above 40%. I actually prefer the humidity above 45% but below 50%.

laurienj9 yes, humidifier on our furnace.

Quite obvious bad milling as Millworkman said. That one board is significantly more narrow than the board it butts up to. Humidity isn't going to fix badly milled floorboards.

that's what I was afraid of. honestly not surprised, though. I just ordered a minwax pencil. I think that's the best solution.

Its winter time. Floors will dry out and shrink if you let them get too dry. There are lots of articles about this. SJ McCarthy gave solid advice.

It looks to me that the gap was filled with putty, which is now deteriorating (crumbling).

Do not humidify your house to 50% if you live in the North. Way too high. You'll get condensation in places you don't want it - like inside the walls.

Ok good to know, I do live in northeast, in New Jersey

I live in KY and keep my humidity at 50% year round. No condensation problems. I have an AprilAir on my 1st floor furnace

I thought there was some kind of filler in there also. Do all the cracks look like that?

This is definitely the worst one but some others are similar

In a well insulated and well designed home you can have the right internal humidity (45%) without having issues with condensation. The wrong level of insulation in an older or poorly designed home and you will always have issues. Condensation being one of many issues.

Here’s another picture of a crack in my bedroom. Do you think they originally tried to fill the places that had gaps ?

Definitely, that right there is sloppy milling and the board should have been culled and never installed. Emphasis on "tried"......................

So I’m going to try the minwax wood filler. Low humidity is probably making this worse, but I feel like the first step is to fill the cracks, while getting humidity right. I’m going to try the golden oak color, seems closest

Filling the cracks will just result in it getting squeezed out next summer. That’s the normal cycle of wood. That’s why old houses have big gaps between boards. The summer winter humidity cycle and uncontrolled humidity. Plus the wider the boards, the more they move.

so what do I do? just live with it? there's no way the builder is going to fix this. I don't have a contract-- we bought a flip.

Live with it as do 90% of those with hardwood floors.

Again, it looks like bad milling of the floorboards in the bedroom. Plus, those wee short boards should never have been installed in what looks like a threshold where the installer could have gotten only one nail (at most) into such short boards. Those short boards would have been a problem even if the wood was perfectly milled.

You don't fix it. You either live with it or replace.

I'm afraid to say the flip is all we need to see. It looks like the install is poor. The milling is bad. And the house is a flip.

The good news is this is fixable (so long as you have left over wood or can find another source for the product). A professional wood flooring installer can pop these miss milled planks out and pop in another. A quick sand/patch of finish and you are done.

A couple hundred bucks and you should be good. The trick will be finding the wood. After that it should be relatively easy.

And PLEASE add in some humidity. The wood looks thirsty. And yes, that's patch material between the planks. It is the crumbly bits. The more you add, the more that will crumble out at a later date.

If you add filler when the wood is dry, what happens when the wood is hydrated?

You have not addressed the cause. Do you know the humidity of you house?

No I just ordered a hydrometer on amazon

Any updates on the humidity levels so far?

yes. the hydrometer i ordered says 34%. and our nest says 30%. so we are looking at getting some portable humidifiers

but i've only had it in the livign room where the big crack was. i need to move it to a few other rooms and see what the readings are

Y'all with your new houses, expensive semi-synthetic-fake-wood floors, and electric-bill-boosting humidifiers are spoiled. Those of us with old houses and wood floors just live with this. Our idea of a modern fix for cracks between the floorboards is vacuum cleaners instead of brooms. :)

... and after all that equipment and monitoring, don't open those windows.... I monitor humidity by measuring the gaps between my 18" pine floors.

I have hardwood and live in Central NY. Winter humidity in my house is about 40%-ish. Summertime....it's anyone's guess because I love to open my windows and feel a natural breeze.

I have a few boards in particular which expand and contract over the course of the year. I always figured it was because it was a wood floor and it would do that.

SJ McCarthy-- is 30% humidity the problem? is that just too low?

Flip explained everything for me. Having worked at HD for several years I learned that buying a flip is something I would never want to do.

Laurienj9, do you understand what "bad milling" is?

I think it means the boards weren’t lined up properly to begin with. But I can’t fix that now, unless I get a floor guy in to pop out the bad boards (and there are many). What I’m trying to do now is address the humidity issue so it stops getting worse

Sigh...30% humidity is at least 15% TOO LOW. You want to get it up to 45% and keep it there for the rest of this floor's life. And I mean that. This floor needs live at 45% - 50% humidity for the next 25 years or longer.

You can do a quick humidity fix (next 3-4 months) using a humidifier in EACH ROOM ($200 each humidifier x number of rooms in your home) or you can pay the HVAC guy/gal to come out and offer a whole home humidifier quote.

It is very tough keeping a home at 45% humidity in the winter (and 45% humidity in an East Coast summer) without a full home system. The energy consumption for room-sized units is enormous. And the effort of filling the humidifier reservoir in the winter and the emptying the dehumidifier reservoir in the summer is a part time job! Without pay.

Ok I’m going to get a quote for a whole house system. Thanks for all your help!

I think it means the boards weren’t lined up properly to begin with.

Not quite. It means that the boards were not cut properly at the sawmill.

Millwork definition: Millwork is a wooden product that has been produced in a mill. Molding and flooring are often produced in mills and are therefore considered to be millwork.

Look closely at the 3rd picture you posted at the top of the thread. See how the center left board is a lot more narrow than the board it butts up (end butt) and how the center right bottom board is a snick wider than the board above it?

What I’m trying to do now is address the humidity issue so it stops getting worse

Good. I was concerned that you might be thinking that increasing the humidity was going to 'fix' the floor. More humidity will help but gaps are going to remain.

It's obvious that the builder shopped price points on the flooring and the installation. You might have had recourse at the time the flooring was being installed, before you signed the closing papers, but that ship sailed two years ago.

I'm not sure it was mentioned previously... and I haven't had time to read ALL of the comments... but at 1st glance, I'd agree with those who suggested a combination of poor milling, less than adequate expertise in the installation phases, and most importantly... the MOISTURE issue, which is always a factor, and having worked on & off on Houzz for years, I'm always baffled by why people don't post the pertinent details when asking for advice...

In this case, those details would be:

1} General Location & relative humidity anticipated on a seasonal basis for that location.

2} Timeframe... because whenever the floor was installed, sanded & finished... the potential seasonal changes SHOULD have been taken into consideration to ensure optimal results.

3} Other little tidbits such as acclimation, working conditions during construction, etc..

I hate to make it seem like "rocket science" but there's a LOT of things to consider when performing this work... and at some point in time, the general consensus became that "If you have a pulse... you're an expert" in the hardwood floor biz. Of course, I'm speaking with only 40+ years of experience behind me, so my opinions should be taken with a grain of salt!

Hope it all turns out... I'll keep an eye on this string.

Best of luck.

@ laurienj9 - how's the HVAC quote coming? And the humidity in the house right now?

Hi. so the issue is I have 2 HVAC units-- one in the attic that heats the upstairs and one in the basement that heats the basement and first floor. The quote from my HVAC guy is $1200 for upstairs, $1,000 for downstairs. I wish I could afford to do both, but I can't right now. So I have to choose one. The biggest floor cracks are on the first floor (and the humidity level was reading as low as 28% some days there). The humidity level upstairs is reading 36%. So does it make most sense to just to the downstairs (even though it would be awesome not to have those annoying mini ones upstairs anymore?) This is the unit my HVAC guy would install: Aprilaire Model #400M . If I installed it upstairs, so you think it would help the whole house overall?

It looks like the humidity is following the general flow of warm air which is "up". Warm air is lighter than cold air so it rises. It looks like the humidity is following that same path. Which makes sense.

You can always START with the main level humidistat and see how much it helps the upstairs. It will *probably be enough for both levels. Of course it will take a full set of seasons before you can be sure this is happening (so sometime 18 months from now).

During that time, you can humidify your lower level and then keep an eye on your upper level humidity (put the hygrometer upstairs and just look at it from time to time). In 18 months you can then make the decision as to whether or not you need the upper level humidistat.

If there is an 8% - 10% difference upstairs (higher humidity) then the lower level humidistat should be able to handle everything....At least that's what your numbers right now are showing and the gaps in the flooring on the main floor are supporting.

thank you! I'm going to start with the main level and monitor.

Someone please explain to me why most people run their bath fans while they shower, even in the winter, when it would make more sense to just open the bathroom door and let that nice wet air improve the humidity in the rest of the house. Heck, if you live alone or you're not too modest, just shower with the door open.

Get enough people taking showers daily and you shouldn't need a humidifier.

I had a humidifier in one of my houses, installed by the PO, but I found that it wasn't really necessary.

That house did have hardwood floors. Maybe cracks between the boards opened up in the winter. I never noticed. I think good hardwood just does that, but I could be wrong.

DavidR

I have to agree with you. Somewhere along the line people started believing that hardwood floors should be PERFECT - no gaps ever, no cracks - PERFECT. And obviously, that was NEVER the case back in the day. NO ONE had whole house humidifiers or dehumidifiers. Heck no one even checked their humidity levels. Wood shrinks in the winter and expands in the summer. I see it in my trim work - every year. What do I do about it? Nothing. It's WOOD. That's what it does. I actually am getting wood floors soon, in just a couple of rooms, and I am completely prepared to live with minor gaps in the wood when the humidity levels drop in my house. No way am I spending extra money on "home conditioning" just so I can have a "perfect wood floor". If you have that many issues with severe humidity levels, then maybe you should just stick to a different floor material.

THAT SAID - the OP got bad flooring. She may be able to improve some of the gaps with a humidity improvement, but the boards like that one in her first pic should never have been laid.

And I do shower with the door open. :-)