Built In Gutter Gutters
Perhaps the rarest form of gutters on homes and commercial building structures are built in gutter systems. These systems are integrated into the design of the roofing structure. They can be a very effective way of managing the flow of water, especially on large roofs or complicated water drainage concerns. Although seen more on older buildings, they are occasionally incorporated into newer structures. One popular use in recent years is using built in water gutter collections for use in energy efficient building design when trying to reclaim water.
Concerns with built in gutter systems
Most of the problems and concerns associated with built in gutter systems come from one root design issue. They are not visible from the ground. Because built in gutter systems are not visible from the ground most are not properly maintained. Most problems occur when a deterioration of the interior lining(or structure itself) reaches a point of failure. Another common issue is that the drainage attached to the gutters gets clogged or obstructed because no one ever gets up on the roof to clear them out or inspect them.
Historical use of built in gutters / places of worship
Perhaps the first use of built-in gutter systems was seen in old churches or other places of worship. Most commonly the systems were built into the eaves edge (or cornice) of the roofing system. Essentially a sloped wooden box is constructed then lined with metal. This is both the cause of this gutter’s greatest strength and weakness at the same time. Whether steel or the more expensive longer lasting copper was installed, both materials allowed a large initial maintenance free period. Even after starting signs of failure often no symptoms of the problem are observed for some time. After the metal has failed water will begin leaking to the sub-structure. This can create very costly repairs requiring the stripping of lining, often rebuilding of substructure and common adjacent roof decking replacement.
Relining or initial installation of built in gutters
The critical component of the built in gutter system is the lining used to prevent water from coming in contact with wood.
In recent years commercial products have come on the market for exactly this purpose. The easiest to install and often most cost effective are rubberized membrane materials that simply adhere in bottom of existing structure. While this will not address any prior damage they can work.
Ultimate solution: Perhaps the best solution if you would like to keep your built in gutters is to have them relined with a heavy weight copper. Copper resists corrosion for an incredibly long time. In fact some of the original built in gutter systems installed in the United States in churches have lasted nearly 200 years. The major drawback to relining with copper is of course PRICE. Finding a quality contractor working with specialized work of the nature can run in excess of $50/ft.