Preservation Pointers: Internal Gutter Systems

Typically, on homes built in the mid-1800’s until the early 1900’s, the most unexpected maintenance problem deals with the internal gutter system. This is because the problem is hidden until the failure has begun. However, regular inspection and maintenance can catch the problem before it is too late, and damage is done.

First, I bet you are wondering, “what is an internal gutter system?” What we call internal gutter systems are also known as “Yankee Gutters,” or built-in, sunken, box or integral gutters. These drainage systems have been used on houses from the 1700’s through the early 1900’s, though they are most commonly found on buildings from the Victorian period. Typically, they are incorporated into the cornice along the roof line, on a porch, or bay window. The usual construction is a wood trough lined with metal. Because of the cornice trim covering the gutter, problems with the metal lining (typically the first problem – allowing water into the structural framing and eventually the trim) remains unseen until damage is spotted from the water infiltration.

Signs your system is not functioning properly include: peeling paint, moist wood, damage to the masonry (at the roof level), and plaster damage on the interior of the house (at the bay window). Unfortunately, once these symptoms are presented, there is often damage to the structural walls or ceiling, not to mention the decorative moldings of the cornice, making the repair a restoration project (replacement to match the original) rather than a preservation project (maintenance) – an expensive proposition.

One way to minimize the cost is to make sure the gutter is regularly inspected and the solder joints in the metal are properly maintained. These inspections can be done semi-annually when the gutters are cleaned of leaves and other debris.

PRO TIP: Never use roofing tar to seal the joints (rather than soldering the metal seams). This will trap the water into the wood, causing the same problems you are trying to prevent.

Some people roof over the internal gutter system and use external gutters for their water management – this is an option for saving money, but it does change the original appearance of the building by covering the decorative cornice. Further, this solution does not address the damage to the structural systems. Often, unenlightened homeowners will wrap the problem in vinyl or aluminum using the “I can’t see it, so it’s not a problem” approach to maintenance. Of course, this causes larger problems and sometimes results in losing the entire front porch.

If you have external gutters, you should regularly inspect them (semi-annually) to ensure that they are doing their job keeping water out of the house and moving it away from the foundation. If replacement becomes necessary, be sure you replace them with half-round gutters and round or rectangular downspout styles appropriate for historic buildings. NEVER replace them with K-style or corrugated downspouts.

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