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Things that grow on your roof will shorten its life span, so do not allow debris such as leaves, twigs, or moss to stay there long if they appear.

Leaves, Debris, Weeds: Growth Of A Green Roof?

Los Gatos Roof with grass and weeds growing on itWinter is a great time for dirt, leaves, and other debris to pile up in your rain gutters. Leave it long enough and there will be buildup.  Leave it a really long time and those bits of dust, plant life and other things will mush together and decompose, eventually becoming plant-worthy soil.  Add a few seeds and some rain, and before you know it, green sprouts are popping up on your roof!

I passed a home in Los Gatos in which this seems to have happened.  Grass and weeds were sprouting out of the rain gutters and had crept onto the roof quite a few inches. (Not a great photo – taken with my ancient cell phone’s camera years ago and enlarged to show the roof but trying to keep the house itself anonymous.)

Why is this a problem? Because the more moisture you have trapped up there and the more organizms growing the faster the roof decomposes. You don’t want things like fungus and dry rot to munch away at your home, and having plants grow on your roof is going to lead to exactly that.

Leaves on Roof in Los Gatos Even if you clean it once a year and don’t give it time to decompose, that might not be enough. If you enjoy lush, mature trees near your home your gutters might need to be cleared a few times per season. When a clog occurs, rainwater may be forced back up, spilling over the edge and possibly right into your roof and down your walls – inside or out!

Clean Your Roof! Things that grow on your roof will cause loads of problems!

Different homes require different levels of upkeep this way, so get to know what your home needs and stay on top of maintenance. Keep your roofs and gutters clean so problems like this do not have a chance to start. It is infinitely easier, and often much cheaper, to prevent this than to cure it!

If it’s hard to keep up with the cleaning, consider investing in gutter guards. Also called gutter covers, strainers, or filters these are installed in the opening to catch debris and prevent accumulation and clogging that stops water flow in the gutter. They still require maintenance, but can lessen buildup and make it much easier to complete your cleaning chore!

Keep a special eye on the north facing area, as moss will attempt to grow on your roof there especially.

Specialty “Green” or “Living” Rooves

While not the subject of this post, adventurous homeowners curious about getting a real “green” or “living roof” should contact a roofing professional with experience in that field. These are specialty systems designed with the weight, water, and material considerations necessary to support plant growth while providing a structurally sound roof – they are complex, expensive, and require different maintenance than more typical systems.

More related articles from this blog:

Why is a Frosty Roof a Good Thing?

Fanciful roof art

Remembering San Jose’s “El Dumpo”:What Makes a Fixer a Fixer?

And related posts from our other blogs:

Silicon Valley is Rife with Roof Rats. Is Your Landscaping Attracting Them?

Some HOA roofing concerns considered here: Silicon Valley homeowner associations: they’re not all alike