Saturday, June 7, 2008

Keep Your Mind in the Gutter

Most homes that I inspect have only partial gutter systems, or they have no gutters at all. Rare is the home that I find having a full complement of gutters, downspouts, and splashblocks. In fact, this is very rare. Home gutter systems are probably my number one pet peeve. It is such a simple and inexpensive thing to install, yet it is one of the most overlooked safety feature of a home. Safety feature? How, you say? Well, there is the obvious… gutters can keep water from dripping or pooling in front of a door entrance, which in turn could freeze. Wet or frozen: either one is a slip hazard. But that’s not the safety that I am talking about. I am talking about the safety and longevity of your home’s foundation.
Gutters, Downspouts, and Splashblocks: The System
Gutters, downspouts, and splashblocks work together like a team. Without one, each of the other two are pretty much useless. Together, they form the roof drainage system for your home. Unfortunately, most people I encounter believe the purpose of a gutter is to keep rain from falling on your head when you go out the door. This is why the vast majority of homes only have small gutter sections over the doors, and usually nowhere else on the home. While gutters will indeed keep the rain off your head while transiting a doorway, it is by no means the true purpose of a gutter system.
The roofs of most homes average between 2000 and 4000 square feet in size. Picture a spring day where it rains hard, all day long, dropping as much as an inch of rain or more in a single day. Multiply that times the square footage of your roof, and you can easily see that your entire roof surface area might collect several thousand gallons of water in a single day. This water has to go somewhere, and that somewhere is down. Here is what I see most of the time: Rainwater (or snowmelt) drips off the edge of the roof. It collects in the soil next to the basement or the crawlspace. It goes into the soil. It comes up in the crawlspace or basement, often causing mold and attracting termites. One day, maybe not this year, but surely, in three years or nine years or whenever, but surely the time will come when we have a prolonged period of rain followed by several (or more) days of incredibly hard freeze. Guess what happens to all that waterlogged soil pressed up against your foundation. It freezes. Ice cubes EXPAND. So does wet soil when it freezes. When it freezes and expands, it has to go somewhere. It will often push against the foundation hard enough to actually cause cracks, thus allowing an easy entry point in the future for even more water. In extreme situations, it can even cause bulging or buckling, causing very serious structural problems that might be un-fixable. Poor (or no) gutter systems are by far the single biggest cause of wet and damp foundations as well as foundation cracking for most homes.
A proper gutter system will prevent all this nonsense. On a home with a good (and complete) gutter system, all of this rain or snow melt is trapped at the roof edge instead of dripping off the edge and pooling against the foundation. The gutters, being properly sloped, channel the collected water to one of the downspouts associated with that particular section of gutter. The downspout (having been annually cleaned of leaves and debris) funnels the water down to near ground level and through an elbow to a point a few feet away from the foundation of the home. This downspout then empties onto a proper splashblock which serves to slow the speed of the water (thus reducing erosion) and also to spread the water dispersion over a larger area. For those of us who are energy conscious and/or looking for ways to be more eco-friendly, I recommend collecting your roof water and use it for watering the garden and watering the lawn. This will also reduce your water bill, thus adding to your expendable income.
Gutters should exist on all roof edges where water can drip. Easy. Trees and the winds are the enemies, because either (or both) can quickly ruin or clog a gutter with debris. Probably half the homes that I inspect have got gutters that have been neglected and forgotten, and are full of muck that makes the gutter totally useless. This causes water to fill the gutters and run down the sides of the house, often damaging the windows and the siding. Clogged gutters will also allow water to run behind the gutter which can damage the soffit, fascia, wall systems and foundations. Over time, granules from your shingles will also collect in these gutters. They become quite heavy and need to be removed. A putty knife or a garden hose usually does the trick. The gutters must be properly sized and placed the right distance from the roof edge, and they must also slope properly to allow proper drainage. Measure the slope… A drop of one inch over the run of 17 feet is just about right.
As you can see, just having gutters is useless unless you maintain those gutters. This is the easy part. Pick two days a year. For me… it is when we change the clocks. We do it twice each year, and we do it about 6 months apart. Furthermore, we are bombarded with commercials and news broadcasts about the time change, and how we should set our clocks. Simple! All the proper suspenses (or ‘prompts’) are already in place. Simply make those two days devoted to periodic “Honey-Do’s” around the house. Such as: Clean the gutters, set your clocks, change batteries in your smoke detectors, test your smoke detectors, wash the windows, and whatever else you might be inclined to forget or neglect. Make a list and simply do it twice a year. Your gutters will last a long, long time, thus protecting your most expensive investment from attack from below (the foundation).
Downspouts are the vertical tubes that are connected to your gutters. They transfer the collected water from the gutter at the roof line down to near the ground level. The number of downspouts necessary for any gutter system is roughly calculated at one downspout for every 35 feet of gutter length. This is a general guide. When you clean your gutters, you should also run some water down your downspouts to ensure they are free of debris. Hornets, birds, and other critters also like to make their homes in these tubes. A missing downspout is much more of a serious issue than a missing gutter, because the water is much more concentrated at the downspout area and all the water is directed towards the foundation at a relatively high velocity as gravity takes it from your roof to the turf, whereas in a missing gutter the water is spread along the entire roof line. A missing downspout focuses all the water in a small area which will puddle quickly and saturate the soil next to, and under your foundation in a very short amount of time. This can easily cause considerable damage to walls, siding, basements, landscaping, and crawlspaces.
Roof gutters on second floor roofs with missing downspouts can cause considerable damage to the first floor roofs if the water is allowed to fall directly onto the shingles. Remember, this water will be collected by a second floor gutter and led to a point that should have a downspout. If the spout is missing… this water will drop at relatively high velocity and will also drop at a high, concentrated volume. This will definitely lead to early shingle failure and should be an item of immediate concern.
As the downspout nears the soil, it generally has a curve to channel the collected water away from the foundation. The recommended practice is to make this end of your downspout so that it channels the runoff to a point 6 feet distant from the home. Again, this is to prevent water from saturating the soil next to the home which could cause catastrophic structural damage. There are several ways to get this 6 foot distance. One way is to simply extend the bend at the bottom of your downspout. These are called “downspout extensions”. Another way is to run the downspout into a drain pipe hidden beneath the soil, and then extend it away from the house. They are more pleasing to the eye than a 6 foot piece of drain pipe and they cannot be damaged by a lawnmower. These hidden drains have disadvantages though… they can become clogged and you may not know it until it is too late. But what if you don’t have underground drains, and you don’t want plastic or aluminum downspout extensions extending 6 feet into your yard. Then consider using “splashblocks”.
Make your downspouts so that they extend only 2-3 feet away from the home. At the end of that downspout where it empties onto the lawn or the landscaping, etc… place a splashblock. Splashblocks are generally made 18-24” in length and can be purchased at almost any hardware store. They can be made of almost any kind of material, but concrete, stone, and plastic are the most common. Browns, greens, and grays are the most common colors, but they can be found in almost every color in existence.
Splashblocks accomplish several very useful purposes. Most importantly, they slow the water down as it exits the downspout. This is to prevent soil erosion near your home. They also act as a dispersal agent. They take the downspout water which is coming out of the spout at high volume, and they spread that out over a much wider area. This also acts to prevent soil erosion. Splashblock design generally includes an inherent slope built into the block, which is discussed in the next section. Splashblocks also create a small area in front of your downspout that will not need mowed or trimmed. This serves to protect the downspout from damage.
I often recommend that homeowners install splashblocks underneath their water faucets on the outside of the home. You would not believe the number of foundation cracks I have seen that are located right behind a water faucet. A leaking faucet, or one that didn’t get shut as tightly as it should have, can saturate the soil next to a home. If followed by a hard freeze, it too can cause structural damage. A splashblock under the faucet can prevent this.
Ground Slope
Ideally, the ground should have a natural slope, leading away from your house. In other words, the soil next to your foundation should be higher than the soil located several feet away from your foundation. This is so that any water not being handled by your gutter system will naturally drain away from your house rather than towards your house. You would not believe the number of homes I see with real pretty landscaping mounds out front that look real nice, but they act like a natural dam. Instead of sloping water away from the home… they actually trap the rain and puddle it against the foundation where it soaks into the soil. Again… it is only a matter of time… maybe next year… maybe in 7 years… but one day it will happen. We will get many days of rain followed by a few weeks of subzero temperatures. These homes will be very high on the list of possible structural damage. Repair costs, assuming the damage can be repaired, can easily exceed $20,000 or more. Take a look at the soil around your home. Does it slope away from the house? Do you have any landscaping mounds that are acting as water dams? The ideal slope is an inch per foot, out to the 6 foot mark, to ensure proper drainage. So… a spot that is 3 feet from the home should be 3 inches lower than the soil next to the foundation.
This is pretty much it. In my humble opinion, a complete gutter system is one of the single most important components of a home. A properly designed and maintained gutter system can protect your most expensive investment for many years to come. You can see this and other valuable information about your home on my web site at
Dappy Jones
OxBow Home Inspections and Radon Testing

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