Aluminum Gutters - Traditional vs. Seamless

Back in the late 80's, I did a remodeling job on a house that was only three years old. The challenge was to convert an open-air deck into an enclosed room. I always prided myself in being able to match all interior and exterior details of the jobs I did. However, this new home included a product that I only used when a customer insisted - "seamless" gutters.

Now don't get me wrong. It's not that I don't like seamless gutters - the concept is fantastic. My dissatisfaction was with the companies and techniques used to install them. The particular people I had to use employed technicians who were definitely at the bottom of the food chain.

Steel vs. Aluminum

Aluminum gutters are a great product. They don't rust, are available in popular colors, can be painted to match other colors and can be shaped quite easily. These rain handling devices have been around for close to 30 years. Prior to the early 60's gutters were made from galvanized steel. Steel gutters were strong and durable. However, installing them took talent. Joints required solder. Painting them was a challenge. If you didn't remove the mill oil finish, the paint would rapidly peel. Aluminum gutters offered a breakthrough in technology.

Seamless - A Myth???

Have you been approached by a salesperson telling you the benefits of seamless gutters? They tell you about how seams leak. They say how your leak problems are gone forever. Hogwash! Seamless gutters have all kinds of 'seams' - places where leaks can develop. There is a seam at each end of the gutter. There is a seam at each outlet tube. There is a seam every time the gutter turns a corner. All of these places can leak. So, don't buy a 'seamless' gutter just because it supposedly doesn't leak.

Aluminum Alternative

OK, so now you don't want seamless gutters. What do you do? Well, how about aluminum gutters that are just like seamless gutters but offer more advantages? Forget about avoiding seams. It is impossible to do, no matter what material you choose to use: steel, copper, tin, or aluminum.

Did you know you can get a traditional aluminum gutter system that looks like a seamless gutter, is stronger than most seamless gutters, and comes in lengths up to 37 feet long? Did you know this same system has an invisible hanger system so you don't see those ugly spike heads?

Comparison Points

If you are selecting gutters for your house, I suggest you focus your attention on important attributes that pertain to how long the system will last. For example, how are the gutters attached to your home? Old fashioned spikes and ferrules or new floating hangers? Floating hangers allow the gutter to expand and contract. Spikes and ferrules do too. But guess what? The spikes and ferrules will loosen over time as the gutters go back and forth!

What about the thickness of the gutter material? The best aluminum gutters are made using aluminum that is .032 inch thick. A thinner material may dent or crease when a branch strikes it or you set a ladder against it.

Hang 'em High

Some seamless gutter systems and traditional gutters are available with a special hanger system. These hangers take the place of the older spikes and ferrules. Aside from being unattractive, spikes also attach to your house in the weakest possible manner. The spikes are driven into the end grain of the rafter tails. Nails driven into the end grain of wood have the lowest holding power.

Some new hangers allow you to nail down through the roof sheathing into the top of the rafter. This maximizes holding power. The hangers also allow the gutter to 'float'. It can expand and contract without restriction as temperatures fluctuate. Expansion and contraction problems can lead to leaks. The gutter will relieve these stresses at the weakest point - usually a seam!

Traditional aluminum gutters can deal with expansion. At least one manufacturer - Alcoa - has a special expansion joint designed to relieve stress. These joints are easy to install. Expansion joints should always be installed on any gutter that extends more than 40 feet. In addition, these joints will minimize stress on mitered joints. So, if your gutters turn corners, say on a hip roof, you had better consider these wonderful devices. Expansion joints are often not available with 'seamless' gutters.

What About Size - 5 or 6 inch?

Aluminum gutters are available in two common sizes: 5 inch or 6 inch. Most houses have 5 inch gutters. A 6 inch gutter can handle more water before overflowing. However, a 6 inch gutter also requires some preplanning. The fascia or gutter board behind the gutter needs to be sized correctly.

Most builders install a 1x6 gutter board. This works well for 5 inch gutters. 6 inch gutter must have a 1x8 gutter board. Without it, the bottom of the gutter can actually fall below the bottom of the gutter board. This often looks very awkward.

Corrosion Problems

Aluminum will not rust. That's a fact. But, it will corrode. Never place aluminum in contact with another metal such as steel, copper, or tin. Electrolysis will happen and the aluminum will actually disappear! Not only that, the chemicals in concrete, stucco, brick mortar, and treated lumber can cause corrosion. You need to isolate the aluminum from these materials with a sheet of rubber or heavy plastic.

Time to Decide

OK, it's time to buy. What to do? Well, think about hangers. Think about expansion. Think about size. Above all, think about warranties and who will install your gutters. Look for a company and an installer who will be around if a problem occurs. Avoid bottom feeders! Think smart.

Downspout Quantity and Sizing

Downspouts come in two common sizes: 2 x 3 inches and 3 x 4 inches. Downspouts depend entirely on gravity to function. Water isn't 'pumped' through them. So, a 2 x 3 inch downspout will comfortably carry the average rainfall from approximately 600 square feet of roof area. A 3 x 4 inch downspout will handle the rainfall from 1,200 square feet of roof. As far as I'm concerned, you can't have too many downspouts. Avoid trying to empty one long gutter at one end with a single downspout. Place a downspout at each end. A 2 x 3 inch downspout is made for 5 inch gutter. The 3 x 4 is for 6 inch gutter. The outlet tube configuration is what limits this fact. Don't forget the bird cages or leak strainers! These devices prevent clogs in underground pipes.