New Home - Subfloor soft spots

Question

We recently moved into a new 3-story townhome 4 months ago and are under warranty. Two months ago we noticed a soft spot under the carpet in the hallway of our third floor. We pointed it out to the construction manager (the development is only about 65-70% complete) and he brought in the foreman for the flooring company that did the install. Without pulling any carpet back or anything, the foreman said it could be damage caused by the drywall guys dumping a load of drywall on the spot, maybe it could be a bad OSB board, maybe it could be a bad OSB joint. He said he wouldn't be sure until the pulled all of the carpet away and cut the area away to replace it.

No work has yet to be done. As of 3 weeks ago, that soft spot had greatly enlarged in size. In addition, we discovered another 3-4 soft spots throughout the 3rd floor. As of a week and a half ago, we discovered another 2-3 soft spots throughout the 3rd floor. Each and every soft spot is in high-trafficked areas. In addition, as i was rushing out of one of the 3rd floor rooms to get the front door, I came over that original soft spot in the hall pretty fast. I heard a massive crack and I sunk a few inches. I am not exaggerating when I say that the only thing that prevented me from falling through into the second floor was the carpet!

I should point out that during the course of construction, there was non-stop rain in this area. In fact, there were periods where they had to stop working on these townhouses due to all of the rain. Two other neighbors in the same building are also seeing soft spots. One of those neighbors was looking through the pictures she took from her pre-drywall walk through, and noticed in the pics that there were water puddles on the OSB flooring, and this is despite the fact that the roof was on by this point!

I am afraid that there could be many more that we have yet to discover, because we never use the guest bedroom, or what about under furniture, beds etc? Also, we have 3 areas on this floor that are tiled and our entire second floor is hardwood. My next fear is that due to the strength of the hardwood as well as the strength of the tiles (plus the strength of the durock under the tiles) that if that OSB is also damaged we might not notice it for years to come!

Fearing the unknown, I demoed a wall on the ground floor, under our staircase landing that was just covering up deadspace to see what was going on. I found wood that was green/brown/black in color due to be water stained and I also found some mold. So we hired an independent home inspector to come through yesterday. He lifted back the carpet and confirmed that the OSB was cracked. He stated that he is not sure what caused the crack, but believes that the rain during construction could be a likely culprit.

While he and I were up on the 3rd floor I mentioned that I think the builder should pull back the entire carpeted area and replace all of the OSB as well as chip out all of the tile flooring and replace all of the OSB in those rooms as well. His response was that sometimes the cure can be more of a headache than the problem itself. So he suggested, that we ask the builder to replace all of the OSB in every area that is carpeted and not just where there is currently a soft spot. He then suggested that the builder do some "exploratory surgery" on the rooms with tile as well as on the second floor that is hardwood. Meaning, go down a floor and cut up into the drywall of the ceiling under those areas that are tiled or have hardwood and have a look around. If the OSB looks bad from the underside in any of those areas, then have the company also replace the flooring there as well.

I spoke with the builder today and it looks like they are willing to do the exploratory surgery under the tile and hardwood areas. But when I mentioned replacing all of the OSB under the carpeted areas on the 3rd floor they balked at that. They only want to replace where there is currrently a soft spot. In my mind, the fact that these soft spots are growing in number over time, I do not want to be inconvenienced with patch work now, possibly some patch work a few months from now and possibly some more patchwork a few months after that. I want them to replace all of the OSB in all of the carpeted areas at the exact same time! And if we find issues during the exploratory surgery, I want all of those fixed at that same time as well.

Am I asking too much? Are my requests resonable? When you drop over 500K on a luxury townhome, you expect quality and not the house from Tom Hank's Money Pit! And just so you know, this is not the only issue with this home. There are many more unfortunately. But this is one of the biggest and of the most immediate concern.

Anyone have any thoughts on my situation? What would you do if you were in my shoes? Should I also be worried about the joists as well? The joists are solid wood at top and bottom and the vertical part looks identical to the OSB. What if these also soaked up too much water???

Answer 1

This is a really good question for any person going through the process of having a home built. A lot of your problems are not out of the norm but really illustrate why it is so important to go to the site a few times a week and walkthrough and take pictures. I cannot stress this enough.

Let's talk about your OSB subfloor.

1. OSB is just pure crap for a subfloor, especially with one with joists more than 16" OC. It is a much cheaper and easier install so builders love it. I don't care what the OSB specs rate it at - it is flimsy material that can't take moisture or blunt contact well. I mean I think they rate 23/32 to be installed on 24" OC which might be what your joist spacing is (what is the distance between your joists?). I can tell you unequivocally that me being a little more than 200 pounds can jump right between two 24" OC joists for a 23/32 OSB board and crack it - been there done that. This isn't a tangent I am on. I am telling you don't replace this crap with the same thing and expect wildly different results because of "water damage".

2. Water damage is real for the OSB subfloor boards and your joists. If your joists have water damage I don't even know what to say. Depending on how bad it is they may need to be take out which means any wall above may need to be removed (swelling will cause tension and unlevel expansion - slanted floors and walls). This is pretty extreme but I have seen it. As for the floors yes water damage causes OSB to become brittle and expand in places.

3. Given #1 and #2 and the amount of places that are "soft" I am really doubting that the OSB was thick enough and/or installed correctly. OSB should be installed using T&G or blocking. It should be perpendicular to joists. This controls some of the deflection and movement.

4. Talking just about the subfloor. The water damage in my opinion didn't matter long-term. Long-term your flooring was eventually going to have these soft spots - within 15 years. The water damage just sped up the process of exposing an unsuitable product for its application. I am fine with OSB + 1/2" plywood. But every single home I have been in with joists greater than 16" OC and only OSB I could tell by walking on the floor in less than a minute. I mean let's just say you had a 300 pound friend over and they were tipping to put a shoe on - your floor could crack. Ridiculous.

---

Lee Sam has a very good answer and I would follow his advice but I would even more so put pressure on the local inspector. As a homeowner - not a contractor or builder - I honestly would be quite aggressive with the inspector. Let him do his job, see what he has to say, but someone in his office really f'ed up and if you aren't aggressive they will just end up covering crap up in cahoots with builder. I would not just push building codes but this is a safety concern. Local city and builder would get sued if someone was seriously injured falling through a floor.

I would ask inspector to condemn the house (more on this later) for safety reasons until the floor gets fixed. I would demand that the house is retrofitted with 3/4" plywood. If the builder refused I would have contractors out there doing it and bill the builder. If he is still building townhouses near you it is very easy to walk around, take pictures, and put leverage on builder by going over your issues with the other home owners.

---

If your subfloors are bad you cannot continue living in the house. The subfloor literally affects almost everything in the house and if there are issues with it then you could be spending a lot of money in the future fixing non-subfloor items because of the bad subfloor. Let's say that someone says you need to add a 1/2" of plywood to fix this... Well all your doors have to be cut, tons of trim work needs to be redone, cabinets may need to be moved which may affect plumbing and electrical, tile work may have to be totally redone. That is just the starter list.

Also there is no way in hell I am letting some builder open up ceilings to put in cross blocking to keep subfloor from deflecting. This is nonsense. Yes it will help keep the floor from deflecting to a point but it is not structural and not tied to the subfloor well enough. It means that your subfloor will deflect but just not as much (until the blocking loosens). A builder suggesting this means the only thing they care about is getting your home "good enough" in their minds until warranty is out. When the builder suggests putting up the blocking I would ask... "So I can tile that area once you do that and it won't crack?" He won't say this out loud but to himself "Of course you can't because the subfloor is still spongy and messed up."

Answer 2

There are several issues here: 1) First, I’d send a “Registered Letter” (the kind with a return receipt) to the developer, builder, architect, HOA, and Building Codes Department outlining your issues, 2) Hire an expert to verify if the subfloor or underlayment has deteriorated, 3) The floor joists are TJI’s. Contact the manufacturer’s representative ( not the local salesman) to examine and determine if the “chords” have delaminates from the “web”, 4) Hire an independent asbestos testing agency to test for mold.

1) Notifying everyone will start the clock ticking. I’d contact an attorney familiar with construction law too. The reason you’re notifying the Building Codes Department is because they are building “unsafe” structures. The Code states the building must support a minimum of 40 lbs. per square foot. They have obviously not done that.

2) The building is constructed with a structural “subfloor” and later (after the roof is on) an “underlayment” is added. The underlayment is not structural, but is used as a finish backing material for the finished materials.

3) Those floor joists are engineered for dry use. They use glue that can withstand some moisture, but not a lot.

4) This can have a long term affect. Get the report in writing.

Oh, the Statue of Limitations is 10 years in the U.S. ... regardless what your guarantee says.