About the House: All About Gutters

By Matt Cantor
Thursday September 24, 2009 - 09:52:00 AM

Now this is a dopey little subject in the face of all the larger issues that one might discuss regarding our homes (not to mention war, famine or social injustice), but it keeps coming up and there are valuable points and, well, a review of this minor but worthy set of issues is long overdue. 

When roofs leak, it’s a fairly big deal for people, though it’s never on my list of top 10 problems. It doesn’t kill; it damages fairly slowly; it’s easy to find (usually), and it’s not the most expensive repair that home ownership brings.  

People are always surprised when I say this, but, if you use that worst-case scenario thinking I so dearly rely on every day, it ends up ranking somewhere between a lack of really good mustard in the house and not getting the best calculus teacher in a community college class. Bad, but not worth missing a night’s sleep. 

And gutters matter less than roofs. They are appendages to assist in small ways, but they don’t affect the space-time continuum more than a wee tiny bit. Gutters are often claimed by those who know relatively little about soil drainage issues to be a major source of drainage problems. Maybe that’s a bit harsh but that’s how I’m feeling tonight. Damned Facebook. 

Gutters can, in fact, direct water much more effectively at a vulnerable portion of one’s foundation than no gutter at all, but, if they do their job well, they can help to move water away from the foundation, and this is where our story starts. 

As I’ve just noted, a gutter can create a real problem, but it generally takes quite a long time (decades) and some endemic (or that catchword of the month … pre-existing) conditions to come to fruition.  

If I dump all the rain water on one side of my roof right on one corner of a foundation that has a very small footing (one that bears upon a small area of soil) then, over time, it will wash away some of the soil below that footing and can, if the conditions are right, cause that foundation section to droop, crack and, by someone’s metric, fail. Again, this requires a smallish footing since a footing that spreads the weight of the house over a large area will be less affected by the loss of some soil. This is a basic principle in foundation design and is why we tend to see either deep legs (piers) or fat, wide footings or slabs used in modern houses. They tolerate these inequities of support better than small foundations that bear the load of large houses. 

All that said, I haven’t seen tons of this in the hundreds of houses I’ve looked at. Occasionally—a few times a year—I will see a corner (or maybe two) of a house right next to a downspout, or next to the trough of water created downhill of a downspout, that is clearly failing from the loss of soil.  

Again, it’s important to note that, were there no gutter and downspout and the natural flow along the grade were to be restored, there would probably be less loss than in the case where the downspout takes all the water off the roof and dumps it with some modest velocity right at the side of a foundation.  

Logic dictates two course of action, one clearly better than the other. Either have no gutters at all and let water disperse along the entire length of the foundation as the roof shape dictates or, better, gather all the water off the roof in some neat fashion and take it away.  

There are other reasons to want to use gutters and one of these is to make it more pleasant entering or walking around your house in the rain. It may seem a minor issue, but it’s nice and that’s where we’re at with gutters. 

An issue worthy of some actual attention is that that some houses have gutters that are attached, not to eaves projections but directly to the walls of the house. Sometimes there is a small separation that is filled with trims, but the basic effect is similar. These are potentially ruinous. The worst ones are the wooden ones of 80 years past that were first attached to the wooden framing of the house and then stuccoed into place, forming what could easily become a drainage pathway from a crack or rotten spot in the gutter right into the wall behind the stucco. You get the picture.  

These have provided lots of income opportunity for pest companies over the years and always get my attention. Gutters should be well away from the walls of the house and are just one more reason to love eaves. Modern architecture has been trying to get away from eaves for decades in the interest of modernity, and while I dig rock-and-roll music and space flight, wooden houses do better when there are eaves.  

This means it’s much harder to build properly (“to keep the water out”) and, over time, someone’s not going to roof right and it’s more likely to leak. It’s not fair to the third owner 25 years later. 

Here are a few suggestions about choosing and installing gutters. I have distinct preferences in this area, and they are all based on seeing the screw-ups and damage that inevitably occurs as the result of various choices. 

Given the types of gutters, I tend to prefer galvanized steel over either aluminum or plastic. It’s tougher and doesn’t get bent up the way aluminum often does (though they could make aluminum thicker and add more bends if they wanted to. If you shop far and wide, you could find really good aluminum gutters but most are second-rate). Plastic might be a good idea, but I have yet to see a single system that didn’t look weird or that didn’t pull apart, leak or have other problems. They are sold as easy to install, and that’s about the only merit they have. 

Copper is fabulous, of course and would be my first choice if I were the CEO of a health plan. If you can afford copper, it’s the way to go. Lasts eons and looks maaaahvelous. 

One last note on gutters (though there is actually so much more that could be said). Make sure they pitch to the drains. 

I’ve actually heard gutter installers (roofers most of the time) say that they install them with the roof line for looks, but that’s nuts. They should always drain at least a little bit in the direction of the downspouts. If a gutter sits dry most the time, it will last far longer. 

Gutters can be painted to increase their longevity, but be sure to use the appropriate primer. There is actually a primer for galvanized metal (who knew?), and using it adds years to the life of that paint job. Primers are always a good idea. 

Another set of items to include in your gutter life is strainers. These catch leaves and keep them from clogging the downspouts. They’re simple shapes formed from wire and often have the shape of a light bulb with the narrow part sliding down into the downspout a few inches. Clean these out every few month and your downspouts will stay free of clogging leaves, toys and bits of falling satellites.  

Now gutters are not that big a deal, except when they’re attached to the wall framing of your house, but they’re a nice neat way to deal with all excess water.  

If you take the water from the downspouts and direct it (pipe it?) to a well considered place, you’re better off, and it’s just more proof of how smart you really are! 


Matt Cantor owns Cantor Inspections and lives in Berkeley. His column runs weekly. 

Copyright 2009 Matt Cantor