How a House Works
A home is more like a living, breathing organism than a pile of lumber and concrete; here's an anatomy lesson
I'll admit it-to call myself an expert on matters of the home is a little presumptuous. When I think of experts, I imagine people like Stephen Hawking rather than some guy named Lou.
Yet for all of my professional life, I have indeed been involved with home maintenance and renovation. And for most of this time, what I have focused on are the mistakes that homeowners make. When I began working at a hardware store in high school, my job was to answer people's questions-and inevitably these concerned problems that they had themselves created: Why was the new faucet that they just installed dripping? Why was the paint that they just spread on the exterior of their house now peeling? And why were the walls in their newly renovated bathroom already beginning to turn gray with mold and mildew? Everyone seemed to have drafty windows, screen doors that wouldn't shut right, and cracks in their living room walls. I always swore that if I ever got the chance to build a house, I would build it in such a way that it didn't have any of these problems.
I got my wish some years later during college-not an entire house, perhaps, but at least a significant portion of it. Looking for a summer occupation, a friend and I started our own company-gloriously named Home Care Services-and promptly found work doing odd jobs for his mother, who worked as a real estate broker. We fixed mailbox posts, planed the occasional closet door, and one day were called to look at a peeling deck on the back of a house new to the market. "Do whatever you can to make it look better," my friend's mother told us, and we set to work. Using my hardware store skills, I noticed right away that the problems seemed to extend far beyond the crackled finish. For one thing, the wood beam connecting the deck to the house appeared to be thoroughly rotted. Crawling around some more, I noticed that this connecting board as well as the structure of the deck itself were made from ordinary pine (the kind that rots) as opposed to pressure-treated wood (the kind that does not). Obviously, the deck had been built by some hapless weekend carpenter who had taken a great set of plans from a do-it-yourself manual. While that was okay, he must have skipped a few pages regarding wood selection. He'd also missed the part about pitch: The whole deck angled not away from the house, as it should have to drain rainwater, but directly toward it. After a few years of having rainwater slosh against them, both the siding of the house and the structure beneath it were beginning to decay. In short, the entire deck was junk, and worse, it was literally ruining the house.
What was to have been about a $75 deck staining job suddenly turned into a $1,500 emergency repair project-and the beginning of a crusade on my part to help people understand how to care for and maintain their homes. What causes mistakes such as this? Mostly ignorance. If things are done incorrectly-whether it's because people are trying to save money or because they really just don't know any better-they can create so many additional problems. That deck was a good example. At a quick glance, it looked okay. But there were two key flaws that anyone should have easily understood-the deck had the wrong pitch, and it was made with the wrong wood. Because of that, all those hours of work and all the money that had gone into it were wasted. Ironically, the repairs ended up costing far more than it would have cost to build the deck correctly the first time.
It's not as if there are a million concepts to learn regarding a home. There are actually only a few key principles to keep in mind, which then have many easy-to-follow variations. In this sense, learning to maintain your home is a lot like learning to cook pasta. If you put the spaghetti into a pot of cold water and try to boil it from there, you end up with a big congealed mess in the pot. You do this exactly once in your life, then never again. Instead, you learn to put it in boiling water, and you come out with perfect pasta every time. With houses, as with pasta, there's a natural logic and order in the way things should be done. Taking the time to learn this, as we're about to do in this book, will empower you to care for your home wisely and with confidence. Before diving in, however, let's take a quick tour of a house and focus on some basic elements.Meet the House
We tend to think of houses as we know them as something fairly recent-dating back to the Colonial era, perhaps, or maybe all the way back to the Renaissance. Yet the origins of four walls and a roof actually go back much further than that. The first identifiable houses are some fifteen thousand years old and are indeed unique. They amounted to a cluster of homes, found in what is now Ukraine, created out of the tusks and bones of wooly mammoths (unfortunately, this is no longer a materials option). Things evolved quickly after that, and you can find references to palatial houses with swinging doors and finely polished floors worthy of a spread in Architectural Digest going all the way back to The Iliad and The Odyssey some three thousand years ago. Indeed, the desire to live in a well-crafted and comfortable house is one of the things that marks us as civilized humans-as does the frustration over not always having things in our home work and feel just the way we want them to.
What exactly is a house? It's heavy, that's for sure, and in order to remain stable it needs to be connected solidly to the ground. If you build a house flat on the ground with nothing supporting it from underneath, all that weight will soon start shifting and sliding and the whole structure will eventually fall down. Instead, houses sit on top of foundations, which can range from fully excavated ones or shallower crawl spaces to concrete slabs. What type of foundation you have mostly depends on what part of the country you live in. If you live in the North, where the ground freezes in the wintertime, you need a full foundation or crawl space that extends down several feet to what is called the frost level or the no-freeze zone. Built this way, the foundation will be immune from all the bucking and heaving as the ground alternately freezes and thaws-an action that could otherwise buck and heave your home right off its foundation, like the losing cowboy in some real estate rodeo. If you live in the freeze-free South, your foundation is more than likely a concrete slab laid right on top of the earth, with no major excavation required. Either way, the foundation has to be set in what is called undisturbed soil, which has settled to the point where it is completely compacted. If you build it on top of a recently filled area, the soil will inevitably settle-as will your house, and in ways not likely to enhance its value.
Now comes the structure of the house, which is usually called the framing. Like the skeleton in our bodies, framing gives a house support and keeps it standing upright. When you think about it, a house has to withstand a great deal of pressure. Not only is its sheer weight bogging it down, but it has to hold up against the onslaught of shifting winds and-depending on where it's located-the weight of winter snows, the occasional hurricane, and even an earthquake tremor or two. The framing has evolved into an intricate design of vertical, horizontal, and diagonal supports that can hold up pressures applied from any direction.
Let's consider a wood-frame house. The framing begins on top of the foundation, with pieces of wood called the sill. On top of the sill, horizontal boards called joists carry the weight of the floor above them and also help to lock the rising walls in place. The walls themselves are built of vertical pieces of wood called studs, which are connected on both ends to rows of wood running around the perimeter of the house, called the plates. Then come more floor joists, which form the structural base of both the floors and the ceilings of a home. If you've got a second story, this process repeats until it's capped off with angled boards called rafters, which rise to form the roof. If you have a solid brick or stone home, you won't have studs, but you'll still have joists and rafters.
The joists and the rafters work in complementary ways to keep the walls standing upright. The joists are actually compressed from the weight they carry, which causes the fibers within them to tense-thus pulling the walls in tightly. The weight of the roof also presses down and out on the roof rafters, but with the opposite effect on the walls: It tends to push them outward. Since the walls are being pushed outward by the rafters and pulled inward by the floor joists at the same time, the forces cancel each other out. Happily, the net force is zero-and so the walls remain standing. Sturdy as it is, however, this arrangement would quickly fall over if the house were buffeted with a sideways force. To further buttress it, the sides are covered with plywood sheathing or with pieces of lumber nailed diagonally across the studs. Built this way, a house is far stronger than the sum of its individual components. It can withstand any pressure-downward, sideways, and any combination thereof.
What comes next are the various systems that make our home life easier and healthier. The gaps in the walls between the studs become filled with one network of pipes that supplies water and a separate network for draining waste. Wires bring electricity to every outlet and light switch, and heating and cooling ducts or radiator pipes snake their way to every room. Doors and windows provide light and access, and insulation in the walls helps buffer changes in temperature. The roof and the exterior siding provide a block against wind, rain, and even sun. The goal of all these systems is to create an indoor space that's distinct from the outdoors-one in which we, and not nature, can control our comfort, moderate changes in the seasons, and regulate for ourselves the arrival of night and day.The Number-One Enemy
So with a structure as beautiful and strong as a house, what could possibly cause it to deteriorate? The answer lies in a simple molecule containing one oxygen and two hydrogen atoms-in short, water. You can live in a home built of
the most massive beams, and water will lay it to waste within a matter of years. It can
seep into the tiniest cracks beneath shingles on the roof, drip through uncaulked gaps around windows, and pool in basements, where it forms rot-causing swirls of humidity. Short of a cataclysmic fire, there's nothing that is more destructive to the long-term health of a home than water.
The most obvious trouble comes from water that pours into the house from outside. Water isn't evil; it's just adhering to the laws of simple gravity and heading downward. If you have a house where water drains from the roof and drips away from the house down a gentle slope after it lands on the ground, your home will be dry. If you have a home situated at the base of a hill or surrounded by a driveway or walkway that pitches toward the foundation, then your home will be wet. Once water comes in contact with wood, it turns something hard and dry and inhospitable to life into something soft and damp and inviting to everything with roots, rhizomes, pincers, and teeth.
In addition to old-fashioned inundation, there's a more subtle yet no less destructive form of water infiltration at work in many houses. As a problem, this is sometimes harder to pinpoint because the water originates inside the home and begins to rot it from the inside out. To see how this could happen, let's take a step back to look at what goes on within a home. Today's homes are sealed with insulation, weatherstripping, and caulk to reduce heating and cooling losses. Unfortunately, this also reduces the ability of moisture to escape from a house. Take a shower in the morning, boil a pot of water, open up the dishwasher and release a cloud of steam-all of these activities release moisture into the home. That may not sound so serious, but combine this with a basic fact of physics-that warm air holds far more moisture than cold air-and you'll begin to recognize what sort of problem can emerge.
In a heated house, warm, excessively moist air gradually penetrates into the walls and ceilings, where it comes in contact with colder surfaces that are chilled by outside air. Where these two surfaces meet, the air suddenly dumps its load of moisture in a process that we all know is called condensation. But what not all of us know is that the moisture ends up lingering right inside the walls. I've ripped apart the walls in some relatively new houses during the course of renovations and found that the structure has been completely rotted as a result of this process. Again, there was no obvious leak that needed to be patched; it was simply damage resulting from chronic condensation. I'll go into greater detail about the causes and remedies for this-which include installing ventilation fans and constructing walls in ways that block the water vapor from penetrating in the first place-in coming chapters.
The Air We Breathe
We take many things for granted in our homes-right down to the air that we breathe. Where does it come from? And how can we be sure that it is pure?
Nothing is as healthy as a drafty house. The air inside it is exchanged every few minutes, and it is always fresh. Any impurities-from things such as formaldehyde emanating from glues in carpeting and in kitchen cabinets to excess moisture that can lead to mold and mildew-simply vent away with the breeze. Most of us, however, have long ago opted against drafty houses. Beginning with the oil crisis in the 1970s and continuing with the rise in home heating prices, it has become a necessity to add insulation and weatherstripping to contain that expensive heated or cooled air. The more expensive fuel becomes, the more people seal their homes up. -- Mark Righter Assistant Production Manager North Market Street Graphics Lancaster, PA
Excerpted from Lou Manfredini's House Smarts by Lou Manfredini with Curtis Rist. Copyright © 2004 by Lou Manfredini with Curtis Rist. Excerpted by permission of Ballantine Books, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.