Roofs With Internal Gutters

Breaking down the pros and cons of flat roof drains.

Roofs with internal gutters.

This type is great for larger buildings and those that naturally pool at the center of the building. There must be no fixings in the bottom or sides of the gutter. Internal gutter construction gutter construction varied from a simple shallow trough or v like a valley detail to a tapered valley laid over firred framing to give a fall figures 5 and 6. External downspouts mounted to collect water flowing from rooftop scuppers.

Metal lined gutters must have welded cross joints and a strip of roof underlay between the metal and the timber or ply. The common gutter lining is either a hot mop built up roofing a torch down membrane or a pvc tpo single ply. Often the outlet to the valley gutter discharged over a small portion of roof before being contained by the eaves gutter figure 7. The built up and torch down roofing will last about as long as the average twenty year steep slope roof and the pvc tpo liners if installed correctly could last as long as the thirty year steep slope roof.

Internal gutters must be continuously supported on timber boards treated to h1 2 or on ply treated to h3. Internal or within roof area gutters also known as box gutters can cause significant inconvenience damage and repair cost if water from the gutter gets into the building structure below. Scuppers are simple to install from a.