I need to do something to bring the humidity level down in my home. The humidity reads from 70% to 80%.

Asked by Lida
New Orleans, LA

I live in the South where the humidity level is high. I have been trying to make my home more energy efficient. I put in two pane, hurricane windows, put R19 in the attic, have a zippered wrap to keep the hot air from coming in the house, house was wrapped and new siding was put on, heat areas from the attic were detected and plugged. The humidity problem began after the house was wrapped and new siding was put on. The stucco walls started cracking. We also had a 4 ton 12 seer air conditioning system at that time but recently replaced it with a 2.5 ton a/c which is supposed to be the right size for our 1,338 square foot house. What is your advice?


Answered by Erik Henry

Brownsburg, IN

ELH Construction LLC

November 28, 2012

In general House Wrap does not prevent air infiltrations. It is designed to keep water vapor away from your exterior walls.

  • If the wrap on your house is designed like Tyvek or Typar, it is semi permeable, meaning vapor can pass only one direction, out.
  • Hopefully your wrap is installed the right side out.
  • I dont' know zippered wrap. 

A dehumidifier will help while you figure out what the real problem is.

You should also check to see if the insulation is blocking the soffit vents in your over hangs. And that you have enough roof vent and that they are not blocked. There should be open spaces maintained by baffles in the attic space to insure proper ventilation.

This is more likely the issue than a problem with the house wrap and stucco.

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