Debris clogging roof valley

[Geoff Rilling]

My house has a steep pitch, concrete tile roof with many intersecting interior valleys. During heavy storms, fresh debris (from redwood trees) collects in the valleys and eventually impedes the water flow down the flashing. I've done my best to clear out the "debirs dams," but every major storm is sure to create a new batch.

Ultimately, I am trying to come up with some method to prevent the debris from blocking the water flow. One idea is to install an exterior flashing valley that might also help the small branches slide down the roof. However, I'm not sure how this can be secured to concrete tile. A variation of this idea is to install a series of flashing "steps" on each set of intersecting tiles creating a flashing waterfall down the valley. And, I have thought of a seasonal solution that would involve laying some sort of light pipe along the valley to keep debris from catching in the intersecting tiles. This might not look very elegant, and I have no idea if it would be effective.

Any suggestions?

[Jimi]

Hi Geoff,

If this isn't causing any problems such as breaching the water repellness of your roof, then I say leave it alone. Posting a URL with photos would certainly help.

Jimi

[Sev]

I fear your roof problem may require the services of an arborist.

[Goedjn]

In the long run, the solution is an open sheetmetal valley, (stainless or copper) with no tiles to snag on. In the short and medium term, I think you need some sort of tool to mechanically clear the troughs.

Maybe PVC pipe with a "T" at the end?