Roof flashings finish and protect the junctions and edges of a metal roof. Ridge caps cover the meeting point of roof slopes, verge flashings protect the sides, and valley and eaves components direct water away. Chimneys, ventilation outlets and roof windows need especially careful detailing because inaccurate cutting or sealing can cause leaks. Flashings also affect the finished appearance of the roof. This article explains the common components, the choice between factory-made and site-formed pieces, and the material choices and factors that affect the cost. Careful detailing contributes to a watertight, durable roof.
Which flashings are used on a roof?
Roof flashings are formed sheet-metal components that protect and finish roof edges and junctions. They include ridge caps, verge flashings, eaves aprons, fascia covers, wall abutment flashings and valley flashings. Gutters and snow-retention components are related roof accessories with their own functions and installation requirements.
Factory-made or formed on site?
Both approaches require accurate dimensions and suitable equipment. Factory forming can provide repeatable profiles, while site forming can accommodate individual details. The required shape, compatible material and coating, workmanship and installation detail determine suitability. Ask SteelProfil to confirm the dimensions, quantity, material and lead time for your order.
GET A FLASHING QUOTE!
Where are flashings used on a roof?
Flashings are used where sheet metal meets other components and where roof slopes meet each other. At the top of pitched roofs, apart from mono-pitched roofs, a ridge cap protects the junction between two slopes covered with metal sheets or profiled metal roof tiles. Ridge caps may have simple, trapezoidal or tapered profiles.
Diagonal junctions on multi-pitched roofs, such as where a dormer meets the main roof, are also important. A valley flashing or valley gutter drains water away and protects the junction. Verge flashing sits along the side edge of the roof, providing protection and contributing to its appearance.
Chimneys and ventilation outlets can be particularly difficult to seal and weatherproof. They often require flat sheet metal to be cut and bent. Take special care with chimney flashings: errors can cause leaks or leave an untidy finish. Similar difficulties arise around roof windows.
The eaves apron, fascia protection, underlay termination and gutter must work together as a complete eaves detail. Whether a particular flashing is required depends on the specified roof system. A membrane does not automatically replace sheet-metal flashings.
What determines the price of roof flashings?
The quotation depends on the metal and coating, sheet thickness, developed width, finished length, number and complexity of bends and order quantity. Use a dimensioned sketch or the specified system detail when requesting a price. Confirm current prices and availability for the actual specification rather than relying on an old example price.
Steel, aluminium and copper require appropriate detailing and compatible adjoining materials. Durability depends on the material, exposure, installation and maintenance. A single service-life figure cannot be applied to every flashing or roof.
