Will my bathroom vent cause ice build up on my roof?

It goes to my attic and runs out through a vent in my soffet.

  3 answers
  • William William on Feb 02, 2019

    No. should not be a problem. The amount of air and for the short time won't affect anything. It vents out the soffit which is under the roof line.

  • Lynn Sorrell Lynn Sorrell on Feb 02, 2019

    Yes of course it can, moisture is being drawn up & out of it. Keep bathroom door open to reduce humidity/moisture in bathroom ,wipe moisture from walls after shower, run an extra heater in bathroom to warm air, or don't use it/vent/fan for awhile til it gets a little warmer in your area.

  • Seth Seth on Feb 02, 2019


    I think what you are asking is can the heat from the bathroom heater/exhaust fan cause ice buildup. Excessive heat and humidity in your attic can cause ice dams. The ductwork from the fan to the soffit should be sealed and insulated. One of the drawbacks to a soffit vent is the warm moist air leaving the vent can be drawn back in by your soffit vents. Make sure your ductwork is insulated, make sure you have good airflow from your soffit vents to your ridge vent if you have one, and most importantly, make sure you have a double layer of insulation on the attic floor, which helps to keep your attic cold.

    • See 1 previous
    • Seth Seth on Feb 07, 2019

      What type of venting do you have in your attic? Do you have gable vents at the ends? Do you have a ridge vent at the top? It seems you have warm air leaking into your attic from somewhere and it's not being vented out well enough so that it is contributing to the ice build up. Warm air can leak into your attic from any penetration from the rooms below the attic going into the attic. Light fixtures, duct work, electric lines, doors, pull down stairs, access hatches, etc. Make sure those are sealed. What type of insulation do you have in your attic and how deep is it? You may not have enough or it may not be properly installed. "Carboard ones?" Not sure what that refers to.