Can this be caused by an undersized HVAC system??

[FONT=Verdana]Check out these photos. This is a one year old, two story house. In one room alone there over 60 patched nail pops. There is excessive nail pops in every room. There are many areas where the gypsum board seams split and needed to be repaired. The caulking throughout the interior of the home has contracted, leaving gaps between the joints where moldings meet, and where the baseboard moldings meet the walls. The hardwood flooring has lots of gaps in between the planks.

There is no visible evidence of water intrusion and the subflooring/crawlsapce is dry. The homeowner just had his HVAC system serviced and the professional told him his HVAC systems (one for upstairs/one for downstairs) were undersized. The home owner says in the winter and summer he runs his heat/air continuously; the rooms never reach the temperature set on the thermostat. Can all of the nail pops, seam splitting, caulk contraction, and floor gaps be explained by an undersized HVAC system?? Thanks in advance.





The results of under sizing an HVAC system is dehumidification.

When were these pictures taken?
What type of heating system is installed: gas, electric, heat pump.

Your post stating that the unit never reaches setpoint is an indication of undersized equipment. Undersized air-conditioning systems will not reach set point but could achieve comfort levels by excessive dehumidification which causes perspiration and evaporative cooling effects to keep the body cool. However, this effect which dehumidifies the body, also dehumidifies the building materials of the house.

The pictures were taken today. The furnaces are gas. The air conditioners are electric. This guy is taking my report to a lawyer tomorrow. He is going to sock it to his builder.


Seeing the heaters are gas, the dehumidifying process is occurring during the heating and cooling season if a humidifier is not installed.

What did you write in your report concerning the issue?

Did you go into this inspection as an expert witness?

In what state is this?

David, this is in North Carolina. I’m still working on my comments but they go like this for each observation:

“There are an excessive amount of nail pops in almost every room of this house. An undersized HVAC system can cause extreme levels of dryness. According to the homeowner, the HVAC system has been assessed/serviced by an HVAC professional. The professional determined that the HVAC system was undersized. Have the HVAC system corrected and repair the nail pops.”

I went into this with my standard contract. I was assessing the house today. Thank God I didn’t do the original inspection. In retrospect I should of had the guy sign a “I get this amount of $$$ if I go to court with you” contract. Feel free to suggest changes to my comments, etc.

Looks like wet house syndrome.

Structural framing members had an excessive moisture content from supplier or weather conditions and builder did not dry the house before finishing took place.

May be very surprised if walls or flooring is ever opened up. Containment and PPE would be recommended if this takes place.

Barry, nice to hear from a moisture specialist!

This house was a production home that was a “rush” job. The owner said they went through three superintendents during construction. During the last month the owner said many crews worked seemingly around the clock, because the house was 3 months over completion date. That would explain why they might not let the house dry.

You have to wonder how the HVAC ended up undersized. The homeowner said this house was originally 2,200 square feet. He asked for it to be “supersized” to 4,000 square feet. The theory is that the 2,000 sq. ft. specs for the HVAC were given for the HVAC of the 4,000 sq ft. house.

This one is a mess.


Send my checks now!

Wet building:


Short explanation:

Longer explanation:](

I’ve also been printing a screen shot every month of the local weather conditions for further records and documentation during my inspection career. If you know when the house was built you have a potential log of the number of days it was wet. Lawyers love these details.

Building Science Corporation - Technical Resources - Walls - Solar Driven Moisture in Brick Veneer
Building Science Corporation - Technical Resources - Mechanical Systems - Discussion of the Use of Transfer Grilles


Keep the checks coming.


Any problem with the operation of windows and doors?

No problems with windows and doors.

Reminds me of a time when GC, instead of using a temp stat on furnace, tied wires together at cp to let furnace run continuously. Result, warped counters, floors, walls and nail pops.

At any rate, seems like alot of hear-say going on with regards to HO / Hvac professional and yourself. Did you see the original heat plan / the heat plan from the HVAC professional (stating units are undersized)?

For all you know, or anyone else knows, this damage could also be intenionally caused by a disgruntled homeowner, who wants out of the deal?