You should delete your other duplicate post.

Your geographic location would help.

Kind of weather you have been having?

How far along is the construction?

Did things get really wet before it got closed up?

Is the house closed up now with HVAC running?

Yikes! Address it ASAP! New construction creates a lot of moisture and off-gassing that settles down eventually, but mold like this already is a huge red flag. The good news is that it means your windows and house wrap are nice and tight, but somehow your attic does not have proper airflow. Check for perforated venting under your eaves, and show is what kind of venting you have at your peak. Ridge vent, caps? How many? If venting was done correctly, the next culprit is the insulation blocking the vents in the eaves. Hopefully it will be a quick identification and remedy. However, you also need a restoration specialist to test and tell you how extensive the cleaning will be. Get multiple bids to make sure you’re getting good diagnosis and work estimates. Call your insurance agent. The house should still be under warranty, yes?

Wait - if builder is still holding the property, you may have some leverage to get it remedied, but probably not much control who and how. You might need a third party, depending on how they handle this. Hopefully the pros here will offer better detailed advice to this effect.

The house has spray foam installation. The house is located in central Texas. The house is 3/4 completely. There is no AC outside unit yet. It has been raining weather on and off the last two weeks. The latest draw is for interior paint. Should I hold back on a percentage or all of the draw till the builder gets the mold situation resolved? I’m afraid he is going to abandon the job. Prior to the mold he notified me his bid price is short over $12,000.

The house was spray foam insulated in January and the roof finished in February. I had concerns about moisture then and addressed them to the builder. My concerns were acknowledged and dismissed. Ugh, now I have mold.

Spray foam insulation is a wonderful material, but it's unforgiving if not installed correctly.

I'm assuming you have spray foam insulation installed under your roof deck which creates an unvented, conditioned attic space. The problem is that it's not a conditioned space if the HVAC system is not operational. Warm humid air will collect in the attic and may create conditions favorable for mold/mildew growth.

I would never install trim or paint anything in a home during construction without the HVAC system running to control the relative humidity. That goes for both conventional (vented) and conditioned (unvented) attics.

The use of spray foam insulation will result in a home with minimal air leakage. Make sure there is a properly-sized system for fresh air ventilation such as an energy-recovery ventilator installed.

Who owns the lot? You or the builder?

If you own the lot, is there a bank involved that might want to know what is going on?

Is this a custom builder or semi-custom tract builder?

Him telling you he is short money is not a good sign. Sounds like a fixed price contract and he is on the losing end of the recent price inflation.

If you own the lot, it might be worth getting an independent inspector to look at the mold.

You definitely need a meeting with the builder to figure this out.

After taking a peek at your other posts, you have been over your head since the beginning. You need more help than this forum can offer. Seek legal help.

"How serious is this?"

Not very.

"Is it even a little normal?"

Yes

"How hard is it to fix.?"

Do nothing until the home has been dried in for a year or so please.

Addressing a condition that may cause serious health issues after living in the home for a year isn't the right order of operations. And it doesn't provide much leverage to get it resolved, either.

Sorry you're wrong Joseph.

No drywall, wood, etc should have even been installed without the HVAC system up and WORKING! 24/7!

And you should be very worried if he's running short of funds. You need to talk to a construction lawyer to see what your options are.

This is very location dependent.

You realized you said "no .. wood should have been installed without the HVAC" - that is a pretty tall order.

Now central Texas is probably not that humid in the winter but I have no idea.

In my area, I have not seen a/c up and running prior to drywall. Interior heaters some times in the winter. I believe we can't have a/c up running until final electric inspection which of course comes way after drywall.

(Never had a lot done in summer months - last 2 move ins were July and Jan. A/C was cranked up by mid June by memory - I am nearly positive our Walnut site finished floors were in for months before a/c turned on - Raleigh - and we lived there for 9 years without an issue).

We are in the process of getting HVAC turned on so that we can lay our site finished floors. We live in NE TN. Have spray foam, sheetrock, and primer on walls. Relative humidity is still too high to put the floors down. Although, they have been sitting in the house for about a month now.

I have never heard of turning HVAC on before sheetrock work. However, this thread and talk of spray foam and mold has me worried. Our attic is not closed up like the OP's was, so maybe that makes a difference.

Just curious, do you have any clothes closets directly accessible from a bathroom?

The house is 80-85% completed. We are not moved in. There is no clothing on the home. And waterlines are not hooked up yet.

@A.M. Texas,

You've become another victim of Mark's sense of humor.

It is a good thing "There is no clothing on the home." But what I want to know is if your house design has any clothes closets directly accessible from a bathroom?

@Mark Bischak, Architect,

By the power vested in me by...well, never mind that part...you are officially promoted to the rank of Captain Non Sequitur along with all the rights and privileges appropriate to your office.

I see your promotion and raise you a dollar.

@Mark Bischak,

Don't take that. Got any bitcoin?

The builder was notified with in the hour of us discovering the mold. He said he would be out the following day and did not show. It’s been three days and no builder. I have requested builders insurance information to start mitigation. He has not replied or provided any information.

Did you notify the builder in writing? Did he reply in writing? If not, it means nothing. Everything going forward should be in writing. When are you planning on seeing a construction lawyer?

People have mold panic. They see a little normal mold and freak out. There isn't a stick framed new home anywhere that doesn't have a bit of mold on the framing lumber. This mold can't live without a water supply. When you're dried in, the mold is toast.

We're shown mold on the end of an attic ladder. That could have been there at shipping. Is more extensive checking a good idea? Of course.

Sorry, I understand what you mean, but I still largely disagree. I have severe allergies to mold, and even for those that don’t, in certain situations mold can have devastating and difficult to diagnose health implications that sometimes become long term. Uncommon, perhaps, but enough to take it very seriously. In her case I would have it thoroughly checked by an expert and remediate if needed before moving in. Ignoring mold until it has ruined a property or caused health issues is to big a risk. Small measures now can avoid large problems later.

Everything has been in writing. He acknowledged receiving the notification the following morning. He replied in writing that he would be out that same day. He has not shown up for two days

@Joseph Corlett, LLC

People have mold panic.

Folks are right to be concerned with anything in their homes that may affect occupant health and safety. To be sure, lumber yard mold is common on framing materials and is inactivated after the home is dried in. Most folks will understand that if the builder will take time to explain and a simple internet search can confirm that no treatment is typically required. Pull-down stairs, however, are not typically stored outdoors like framing lumber is, and not installed until after drywall-- so they never get wet. Indeed, by the time interior trim, interior doors and pull-down stairs are being installed, the interior environment of the home should be conditioned using either portable equipment or the home's HVAC system. If drying in a home were the only condition required to prevent mold, it would not have taken up residence on the OP's pull-down stairs.

While we don't have all of the information, it's not that difficult for anyone with knowledge of basic physics or building science to connect the dots. The photos, combined with the OP's description that spray foam was installed under the roof deck, that there is mold on the rafters, and that the HVAC system is not operational points to a moisture problem in the (unvented) attic. I suspect your physics is fuzzy, so let's take a look at what's going on. Hot air rises. Moist air rises (it's less dense than dry air.) In a home, that means moisture and heat can accumulate in the attic volume. Designers can address those conditions by choosing to either vent the attic or to create a "conditioned" attic. The building code doesn't dictate the choice, but it does provide specific requirements to be met in each case. The designer of the OP's home has opted for a "conditioned" attic.

I'm not sure which code is in effect in Texas at the moment, but in the 2018 IRC, the requirements for unvented attics are listed in section R806.5 Among other things, the code requires the installation of a vapor diffusion port at the highest point in the attic and that conditioned air be supplied at a rate greater than or equal to 50 cfm/1,000 sq. ft. of attic area. We don't know if the first condition has been met, but we know that the second hasn't. Without the supply of conditioned air, the relative humidity in the attic is obviously sufficient to allow mold growth.

Spray foam insulation is wonderful stuff, but it is unforgiving of installation errors. In this case, some form of temporary attic ventilation should have been provided and the installation of spray foam in the attic should have been deferred until the HVAC system was operational. Getting the HVAC system operational should halt the propagation of mold and an expert can be consulted with regard to any abatement.

At today's prices for spray foam insulation, a conditioned attic is a significant investment. Homeowners will be well served to ensure their builder knows how to construct one without causing problems like the OP's.

@Joseph Corlett, LLC Thank you so much. That is very helpful and informative information.

I discovered mold in our attic shortly after moving into our new house. The builder was called and came out with the framer and design planner. They figured the ridge vents and another kind I dont remember the name of were insufficient because the code for insulation here in MA had changed requiring more insulation than before. So they ended up treating the mold and then put in those end vents as well. Haven't had a problem since. They say mold doesn't grow down but even so, who wants mold anywhere in their house? Btw, we did not opt for spray foam insulation. Good luck.