How does a tree wear a roof?
A tree wears a roof by rubbing, dropping debris and holding moisture. Each works in its own way, and each shows in a different place on the covering.
A branch that moves in the wind rubs the covering at the point of contact, and the granules come away. A limb that rests on the roof can crack a tile or lift a shingle at the edge. Both faults grow slowly, which is why they are often found late.
Leaves and needles block the gutters and collect in the valleys. A wet mat of debris holds water against the covering and the sheathing, and it can keep the wood damp for days after a storm.
Why does shade matter as much as the branches?
Shade keeps the roof wet longer, and wet covering grows moss and staining. The north face of a house under heavy canopy is often the first to show the damage.
Moss on a covering holds moisture against the granules and the mat beneath. Over time that wet softens the sheathing and loosens the nails. The technician checks the north and shaded faces first for moss and dark staining.
Cleaning the moss is done gently. A hard brush or a pressure washer can remove the granules, and the covering is then less able to shed water. A soft brush and a low-pressure rinse are the safe method.
What should the owner do about the trees themselves?
Trees that touch or overhang the roof should be assessed by a qualified arborist, not cut by the roof crew. The technician notes the branches and the contact points, and the owner decides what to do with them.
A roofing crew is not a tree service, and a limb cut from a ladder near the eave is a serious fall risk. The owner is advised to ask an arborist to assess the canopy and to cut back any limb that touches the roof.
The technician records the contact points on the scope, so the arborist and the owner have the same map of the problem.
How are the gutters and valleys kept clear afterward?
A cleared gutter and valley stay clear only with a routine. A check after each leaf fall and before the wet season keeps the outlets open and the valleys running.
The owner keeps a short list: clear the gutters after leaf fall, check the valleys before the rain and look at the outlets after each storm. The list is simple and it prevents most of the overflows that trees cause.
Gutter guards can reduce the build-up in a heavy leaf year, but they do not replace the check. A guard can hide a sagging run or a blocked outlet beneath it, so the technician looks at the guard too.
How is a tree-lined roof checked after a storm?
After a storm, the check looks first at the gutters and valleys, then at the covering under each branch, then at the attic above the north and shaded faces. The order follows where the water is most likely to have gone.
Gutters and valleys are checked for debris and for water standing at a dip. Debris that was carried into the valley by the storm is cleared, and the flow is tested with a hose so the owner sees whether the valley now drains.
The covering under each marked branch is checked for granules, cracked tabs and debris held in a crease. The attic above the shaded face is then read for dark sheathing and rust on nails, since the wet under heavy shade shows there first.
What about moss on a roof in a shaded lot?
Moss on a roof is a sign that the covering stays wet, and it is treated as a symptom of the shade rather than as the main fault. The moss is cleaned gently and the cause is addressed by the owner with the arborist.
A moss-covered covering holds water against the granules and can lift a shingle at its edge. The technician removes the moss with a soft brush, avoids pressure washing that strips the granules, and checks the sheathing beneath any area that was heavily covered.
Shade that keeps a roof wet is reduced by cutting back the canopy, which is the arborist's work. The roof crew records the shaded faces on the scope so the owner can see which faces need the most attention after the trees have been trimmed.
