Leaf strainers for roof drains/downspouts

[Kantaro]

I have a low sloping roof with 1.5" drains that connect to downspouts, like this:

I found two of them clogged with leaf/debris. On the first one, the actual drain hole was completely filled with leaf bits and debris, but was apparently still draining as the surrounding area was dry shortly after a rainfall. However, the second one had pooling water as the drain inlet was covered by leaves and not draining. Rainwater would flow over the edge of the roof in this location.

I was thinking of adding these leaf strainers on the drain inlets but was wondering if anyone had any feedback or experience? They are meant for downspout inlets in gutters and the reviews are mixed. They seem to cause gutters to back up and require more frequent cleaning, but not sure if that would apply to a roof drain application.

 

[JHZR2]

In high school I did a lot of leaf removal and cleanup. I helped some folks with flat roofs that had that sort of a device. They worked but they too clogged up. They’re ok if you just have leaves, but if there are maple whirlybirds, oak strings, sycamore pods, etc., all that stuff in the right situations can clog too. The solution is to keep things cleaner, better, more often. Or add bigger and more downspouts. Neither are necessarily a great option.

 

[thastinger]

Those things will clog up faster than the open downspout will.

 

[JTK]

I have wedge shaped strainers over the downspout holes in my gutters. Like @JHZR2 said, all this does is help prevent clogs in your plumbing. You have to clean the strainers often.

 

[Lubener]

The downside of those strainers are they will do their job, clog and stop the water from flowing into the downspout. Be prepaired to make visits often to the rooftop to clear them.

 

[Kantaro]

The main goal would be to prevent the drain from being blocked so that water does not pool and overflow over the roof edge, but it sounds like these don't work as well as I had hoped.

 

[slo town]

I get up on the roof several times a year with my backpack leaf blower and blow the gutters and valleys out, plus the flashing around skylights, chimney, roof vents, etc. I'm always amazed how much dirt collects in the nooks and crannies on the flashing.

You might want to consider doing it this way if you have a roof flat that's not too steeply sloped and isn't made of something slippery - and your house is single story and heights don't bother you. Just be careful. I'm still doing it at age 71.

I always make it a point to do it before incoming storms arrive.

Scott

 

[Kantaro]

Here's a drone shot of the two drains in question for fun. The drain to the left of the chimney is the one that was clogged with small debris but still draining. The drain to the right was blocked and not draining, with pooling water. The drain on the right is close to a maple tree.

I'm almost wondering if the pooling water on the right overflowed to the left drain, carrying bits of decomposing leaves over which clogged the left drain.

 

[ecotourist]

I have leaf strainers similar to those in my downspouts. They're plastic but similar.

They plug up with leaves and debris but they also keep a lot of stuff out of the downspout.

I'm training my 12 year old grandson to clean the eves troughs. At some point I won't be able to do it anymore.

Here's an idea. If you expanded the circumference (producing way more surface area) it would take a lot longer to plug up. How about a heavy 12" diameter X 4" high "squirrel cage". That would require a lot more debris before it plugged. You would just leave it loose on the roof but centered on the drain.

 

[MasterSolenoid]

Here's an idea. If you expanded the circumference (producing way more surface area) it would take a lot longer to plug up. How about a heavy 12" diameter X 4" high "squirrel cage". That would require a lot more debris before it plugged. You would just leave it loose on the roof but centered on the drain.

I like this idea.
It's not really altering anything, only making a decent idea way better.

 

[ecotourist]

I like this idea.
It's not really altering anything, only making a decent idea way better.

Thanks. A little modification that would improve this idea is a thin, highly compressible (maybe soft foam) "gasket" between the squirrel cage and the roof to prevent debris getting underneath - but only if the surface is uneven. If the surface is dead flat, there's no need for it. You want it highly compressible so the squirrel cage isn't raised as that could cause water pooling.

 

[Nukeman7]

Where do those drains exit relative to the building? If you can easily access the bottom opening of each downspout, all you need to do is to blowout the drains with a leaf blower every few months. The exhaust discharge of a shop-vac will also do if you don't have a leaf blower.

 

[shortyb]

Cut down the maple tree .

 

[Kantaro]

Here's an idea. If you expanded the circumference (producing way more surface area) it would take a lot longer to plug up. How about a heavy 12" diameter X 4" high "squirrel cage". That would require a lot more debris before it plugged. You would just leave it loose on the roof but centered on the drain.

Would this be similar to an atrium grate?

A solid idea but not sure how feasible it would be to retrofit since the roof isn't flat around the drains - the drains sit in a valley.

I think I may still give the leaf strainer a try and see how it goes. I found a German supplier that uses similar strainers for their flat roof drains:

 

[ecotourist]

Would this be similar to an atrium grate?

View attachment 225565

A solid idea but not sure how feasible it would be to retrofit since the roof isn't flat around the drains - the drains sit in a valley.

Not a bad idea but wider would be better. I'm thinking of something more like a squirrel cage fan rotor. As they're often quite light you might have to put a brick on it to weigh it down. Looks something like this:

https://www.bing.com/th?id=OIP.t35MgUahKkAxM4djIw0oagHaHl&w=150&h=154&c=8&rs=1&qlt=90&o=6&pid=3.1&rm=2

You probably wouldn't want to buy a new rotor (could be expensive) but a scrap one would work just fine. The rotor from a bathroom fan is the right idea though wider would be better.

As for the valley issue, that's why I suggested adding a foam gasket. The ideal size would be a compromise between wider having more surface area and smaller working better in a valley. Suggest you try a few cardboard circles and see what size is the best compromise.

 

[mr_boring]

Call me nuts if you will but I usually clean mine when it's raining. I just use my 6 foot ladder (I love my single story ranch) and only have to break out the 12 footer for one. If I do it every 6 months, fall and spring, I only have to swirl it around a bit to get all of the detritus flowing out.