Why do wind and water get in at the edges first?
The edges of a roof are held by fewer fixings and take the most wind, because air lifts under an overhang and pulls at the first course. Once an edge moves, water follows the gap, and the rest of the roof cannot hold it back.
Wind pressure is highest at the eave, the rake and the corners of a roof, and that is where the covering is most likely to lift. A lifted course exposes the fixings beneath it, and the water that follows is driven under the lap by the next gust.
Edge metal does a similar job at the rake and the eave. When it bends or pulls away, the sheathing under it is exposed to wind-driven rain.
What does a nor'easter do to a roof that an ordinary storm does not?
A nor'easter brings sustained wind, often gale-force, together with heavy rain or wet snow and sometimes coastal flooding. The load lasts for hours rather than in gusts, and it comes from the water side.
The National Weather Service describes nor'easters as strong low-pressure systems that bring heavy rain or snow, gale-force winds and rough seas, and it notes that they are most frequent and most violent between September and April.
On this coast the wind often comes from the east, along the axis of the Sound. That direction is the one that drove surge into the western Sound during Sandy, and it is also the direction that pushes rain under the windward laps of a roof.
Is a hurricane barrier enough protection for a roof on the shore?
No. A barrier protects against surge, and a roof needs its own check. The barrier that guards the downtown in Stamford does nothing for the covering, the fixings or the flashing on a house.
The Stamford Hurricane Protection Barrier was built in 1969 and is operated by the US Army Corps of Engineers. It protects the central part of the city from surge, and the barrier is a public works matter rather than a roof one.
Irene and Sandy are the storms that show the range of what a roof has to face on this coast. The wind and water that came with Sandy can loosen a roof that stood well through an ordinary rain, which is why the storm record matters for readiness.
What should a waterfront owner check that an inland owner might not?
A house on the water sees salt air as well as wind, and its metal fixings and flashings are where that exposure shows. The sources do not give a lifespan reduction for salt, so the check looks at what can be seen rather than predicting how long a fixing will last.
The fixings and metal joins at the edges are the first places to look on a waterfront house, because they carry both the wind load and the salt. Matched or isolated metals at each junction are checked, since a mismatch is where corrosion starts.
The check does not claim a salt-driven decline in the roof's life. It records what is seen at each fixing and each edge, and it leaves the owner to decide what to replace.
What moves the price of readiness work up or down?
The price depends on the size of the roof, the number and type of edges and penetrations, the access, and the amount of repair found during the check. It is explained and approved on site before any work starts, and no figure is given here.
A small roof with few penetrations and clear access is a short check. A large roof with several planes, a tile or slate covering, and many chimneys or skylights takes longer to walk and to record.
Work that is found during the check, such as a loose edge metal run or a lifted tile at the rake, is the usual reason readiness work grows. The technician reports what was found and what it changes, and gets approval before the next step.