roof skylight

If you have a skylight on your roof and live in an area that sees a lot of rain and unpredictable temperature changes, you may have noticed signs of leaking or have heard drops of water coming from your attic. Your next course of action should be to determine if the source of the problem is a leak or if it has been caused by condensation.

What Causes Condensation?

Condensation happens when vapour in the air is changed into a liquid state. An example of this is when you take a hot shower, the water vapour gas that is present in the water comes in contact with your cold mirror, causing the water vapour to condense or to into a liquid. You will notice it when you see beads of water and fog on your mirror after getting out of a hot shower.

What does Condensation mean for your Skylight?

Skylights see more condensation than most areas in your home because the water vapour rises to your ceiling and collects on the surface. During the winter, you may notice more condensation because of the temperature difference between the inside of your home and the outside increases.

To decrease the amount of moisture in your home, you can use a dehumidifier and ensure you have enough ventilation. Here are a few things that can cause higher amounts of humidity levels within your home:

  • A high number of occupants in the home
  • Drying firewood inside
  • Drying clothes inside
  • Humidifiers
  • Showering and cooking
  • Damp basement, crawl space or sump pit
  • Houseplants, hot tubs, indoor pools, and aquariums

It is recommended that you keep your home’s relative humidity between 30 to 45 percent in the winter or when the temperatures are below minus 5 degrees Celsius. If you have a low percentage of humidity, you risk aggravating skin allergies and respiratory infections. If you have higher levels of humidity, mould, bacteria, and viruses have a better chance of spreading throughout your home.

Improving your Home’s Ventilation

For today’s tighter built homes that use more efficient building materials, to get the optimum attic ventilation you will need to exceed the minimum building codes. It is recommended that you should have one square foot of ventilation for every 150 square feet of attic space. Half of the ventilation should be represented by intake vents and the other half by exhaust vents such as ridge vents. The minimum building code requirements use the 1/300 ratio instead of the 1/150 ratio.

You will need a delicate balance of intake and exhaust because, without it, it can cause problems for your entire roofing system. Warm air that is full of moisture can build up in your attic instead of flushing it out with a cooler, drier air.

If you are looking to improve your home’s ventilation, or if you think your skylight is leaking, the professional roofers at All Star Roofing would love to assess your entire roofing and ventilation systems to figure out where the problem is and fixing it right away!


Contact us if you have a Leaking Skylight!
All Stars Roofing Inc.

11-5125 Harvester Rd
L7L 6A2

Call us: 647-808-4044