10 Ways the Plants in Your Yard May Be Endangering Your Roof

You know how important it is to take care of your roof. You perform regular maintenance – from snow removal to scheduled inspections. But sometimes the biggest threats to your roof’s integrity are the ones you grow yourself, namely the trees and other foliage in your yard.

Here are 10 threats to your roof caused by plant growth (and what you can do to prevent the damage).

Climbing Vines

Winding vines can add an air of elegance and old world charm to your home’s exterior. But, when the vines creep onto the roof, they can soon cause extensive damage, like the following.

1. Mould

Rooftop vines inhibit snow and rain runoff. This can cause standing water or collected moisture beneath the vines. This dark, damp environment encourages dangerous mould growth.

2. Pests

Climbing vines create a ladder from the ground straight to your rooftop. This may lead to problems with the following pests:

  • Invasive species of ants, mites, and roaches
  • Rodents, like mice and squirrels

3. Structural Damage

Strong vines, like wisteria, penetrate structures easily. This can remove shingles. Some species of vines are aggressive enough to raise a roof. Most vines can be trimmed down and retrained, but once penetration occurs, you will need to contact your Calgary roofer for repairs.

To prevent roof damage from climbing vines, keep them trimmed. If you want vines to shade your roof, build a trellis to support them instead of letting them grow directly on the shingles.


In moist climates, some organic growth on the roof is common. Light algae may be unattractive, but it is easily removed and doesn’t usually represent a threat. However, most types of moss will endanger your roof in the following ways.

4. Intrusion

Moss’ tiny roots find the openings and imperfections in roof shingles and latch on. This compromises roof seals, causes shingle loss, and leads to leaks and wind intrusion.

5. Water Damage

Like vines, moss cultivates a moist environment protected from direct sunlight. This encourages mould growth and can rot your shingles.

A chemical cleaner, like bleach, can kill and remove algae. If you have a moss issue, you will need to use a moss killer, like potassium salts, before attempting removal. After the moss is gone, talk to your roofer about installing zinc sulfate strips on the roof to prevent regrowth.


Trees beautify and define a yard space. They can even create wind blocks to stave off winter weather and serve as shade in the summer. But, when your trees become too tall or overhang your roof, they can cause several problems, including the following.


Tall trees with a canopy of branches present a beautiful picture, but if those branches touch your roof, they probably also damage it.

6. Pests

If vines are essentially a pest ladder, adult trees with overgrown branches are an express elevator system. Overgrown trees provide rooftop access to a number of pests, including:

  • Raccoons
  • Rats and mice
  • Squirrels

Once on the roof, these pests may scratch or chew at your shingles and fascia. In extreme cases, vermin may invade your attic space from your roof.

7. Structural Damage

If long branches touch your roof or grow directly above it, they may damage your roof in the following ways:

  • Broken and fallen branches can leave holes and damage shingling
  • Constant abrasion from overlaying branches may harm or even remove shingles

To prevent branch damage, keep your trees trimmed back at least 3 metres (10 feet) from the top of your house.


If your trees’ branches hang over your home, chances are autumn leaves float down onto your roof. Piles of leaves on your roof may result in the following problems.

8. Clogged Gutters

The poor drainage resulting from leaf buildup in gutters results in several types of damage, including paint and siding damage. But standing water in gutters may also wick upwards, under your sheathing. This causes rot that may even extend to your rafters.

9. Invasive Growth

When fallen leaves form drifts in the crevices of your roof, they create ideal growing conditions for the following invasive species:

  • Mosses
  • Mould
  • Weeds

10. Rot

As mentioned above, plants that retain moisture and shield your roof from direct sunlight cause mould. As leaves decompose on your roof, they can cultivate rot that may penetrate your shingles and sheathing, causing damage that requires extensive roofing repairs by a professional roofer.

When the leaves start to fall, take the time to clean them off your roof regularly to maintain its structural integrity.

Have your trees trimmed and gutters cleaned regularly, especially during the fall and winter, to maintain your roof.

If you have concerns about how your landscaping choices affect the structural integrity of your roof, call Century Roofing Limited in Calgary. Our Calgary roofing contractor’s evaluation can help you curb any negative side effects before they cause severe damage.

When you do visual roof inspections, look for any signs that your plants are endangering your roof.