If not maintained properly roof valleys can become clogged with leaves and other debris which can cause the metal to rust and the roof to leak.
Rusty roof valleys.
Roof one side of the valley running the shingles across it.
Lay one and two tab shingles as you near the valley so full size shingles will run across the valley.
You can see that repairs were attempted using a black asphalt based flashing cement.
Even badly rusted flashing can be renewed if it s caught early enough.
In more rustic styled designs we see it used more with corrugated metal panels.
They can last for more than 20 years but external factors can considerably shorten that period.
Wet leafs stick to the valley and corrosion leads to formation of rust bubbles.
Felt tar paper some roofers offer nothing more than roofing felt as a valley liner.
Fold the top over the roof ridge and cut the bottom along the drip edge metal.
Believe it or not one of the most common causes for roof leakage is leafs.
Rusty flashing is more than just an eyesore.
The flashing in the valleys of your roof depends on a smooth surface for rain to wash debris off your roof.
Roof valleys are troughs that discard runoff water where two sections of sloped roof meet.
A rusty valley on a tile roof which needs to be replaced typically where a valley is located on a roof roof valley replacements are fairly common especially on tiled roofs.
The copper roof valley shown above cracked and leaked from thermal movement.
A popular trend that has been occurring in mountain retreats and ranch style homes a corten roof offers a unique appeal to many homeowners.
The internal angle formed by the intersection of two sloping roof planes to provide water runoff.
The flashing around vents chimneys and skylights prevents rain from leaking in.
To clean and refinish a roof valley.
With a clean valley you can lay down some peel and stick roofing membrane.
Severely rusted flashing may warp curl or even develop holes exposing your home to the possibility of damaging leaks.
Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles.
First clean the debris out of the valley including sawdust nails and whatever else is in there.
Shingle the other side of the valley the same way.
This is because the old valleys used to be galvanised and they start corroding with time especially if they trap leaves.
Unfortunately not only did the flashing cement give only short term relief its chemistry attached the copper below thinning and corroding the copper.
However roofing felt s waterproofing ability is ruined the moment the asphalt shingles cedar slate tile etc.
In modern metal roofing applications the trend tends to be using a weathering steel on a standing seam roofing panel.
Lifespan of roof valleys is relatively long.