I believe you are referring to an area of the roof called a valley. A valley is formed anywhere the downward slope of two roof surfaces meet.
A 'Skylight' and a'Roof Truss' are 2totally different parts of a building. A roof truss is a timber or steel framework used to carry the roof cladding. A skylight is a panel in a roof which contains a panel of clear plastic or glass which allows the sunlight to shine into the room of the building.
If the gable is formed by the two slopes and a horizontal line, it is called a gable roof.
Continuous roof systems are called membrane roofing. This roofs are used for buildings and tanks. They are built on flat or nearly flat roofs to prevent leaks and help drain water off.
Purlins are used on double roofs. They effectively reduce the span of the rafters and limit their size to ecenomical sections.
atrium
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No, the roof is made from tiles, wood and metal.
no
it is called a roof
The roof
roof top
Roof
It is what you called the planning for the roof.
Yup called a diaphragm tank and NOT connected to the domestic supply
A post that supports a roof is called a column.
The window in a ceiling or roof is called a Skylight.