Built Wrong From The Start

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10

Built

Wrong from the Start

blunders that rot your house, waste your money, and make you sick

BY JOSEPH LSTIBUREK

I’ve been a building scientist for more than 20 years. Before that, I was a builder. Even though I followed standard building methods, some of my houses were turning into drafty wrecks that were rotting on their foundations. What went wrong?

In 1983, I went back to college to get my Ph.D. in building science, the study of how buildings work and why they fail. Houses are more complex than they used to be. They have more insulation, they have elaborate heating and cooling systems, and they are built to be nearly airtight. These components can make com- fortable, energy-efficient houses that serve their owners well. But if they’re put together wrong, a house and its occupants can be in for some serious problems.

I’ve turned the basis of the mistakes I made as a builder into one of the lectures that I give at build- ing conferences across North America. While I de- liver these seminars in a somewhat lighthearted manner (sometimes to standing-room-only crowds), I can assure you that these blunders are not funny. 􏰀

Joseph Lstiburek, P.E., lives in Westford, Mass., and works just about anywhere. His Web site is www.buildingscience.com.

one

Plastic vapor barrier Drywall

Wrong

VAPOR BARRIERS ON BASEMENT INSULATION WILL ROT YOUR WALLS

We expect a house’s walls to get wet during construction, either from the weather or from the materials (that’s why joint compound is called mud). But they also can get wet once the house is finished and occupied. Wet walls need to dry.

There are two types of wall that can get wet: regular walls above the ground and basement walls below the ground.

Additionally, there are two sides to a wall: an inside and an out- side. It’s smart to design walls to dry to both sides, but drying to at

APRIL/MAY 2004

least one side is a pretty important objective. A vapor barrier on the inside of a wall means that the wall can dry only to the outside. This is OK for regular walls in cold climates (like Canada, where there are only two seasons: last winter and this winter), but it’s not OK for basement walls, not in any climate. Basement walls can’t dry into the ground because—you guessed it—the ground is wet. Because basement walls can dry only to the in-side, wrapping the inside of a finished basement wall with a sheet of plastic is a bad idea. Wet basement walls wrapped in plastic can’t dry. We must build walls so that they can dry during wet seasons (drawing facing page). By using extruded poly- styrene (XPS) foam for insulation, you can eliminate the inside condensing surface and prevent water intrusion from the out- side, too

two

VENTED CRAWLSPACES ARE MOIST ENOUGH TO GROW MUSHROOMS

In the old days, we didn’t insulate crawlspace floors, and we didn’t air-condition houses. Crawlspaces (especially the floor framing) were warmed by the houses themselves. Now that we insulate floors, crawlspaces are within a degree or two of ground temperature. During most of the summer, this temperature is below the dew point of the outside air, even up north.

Ventilating a crawlspace allows moist outside air to con- dense on cool crawlspace surfaces. Consequently, the venti- lation air is wetting the crawlspace rather than drying it. It’s like opening a basement window in July: The walls sweat. And wet walls become moldy walls quickly.

The whole point of venting a crawlspace is to remove moisture. If we could import hot, dry air from Tucson to vent moist crawlspaces in Tupelo, venting crawlspaces would be a great idea. But for Tupelo air to vent Tupelo crawlspaces, the air needs to be dry enough to pick up moisture, and it needs energy (heat) to evaporate the moisture. This isn’t going to happen, and here’s why: Tupelo air isn’t hot and dry. Neither is Toledo air, Tallahassee air, nor Toronto air.

A crawlspace is just a mini-basement and should be treated as such. It’s like a basement for a troll. You should condition the air in your mini-basement. Make it part of the house be- cause, despite what you may think, it already is. Heat it in the winter and cool it in the summer with a supply duct or grille (but ask your fire inspector about this). Don’t insulate the floor; insulate the perimeter and install a continuous ground cover to keep out moisture.

three

DUCTS AND AIR HANDLERS IN ATTICS WASTE MONEY AND SUCK IN BAD STUFF

Why put the heating and cooling sys- tem outside the space that it needs to heat and cool? We insulate walls to R-19 and ceilings to R-50, yet we slip an R-4 sleeve over ducts and call it good. Where were the adults when this decision was made?

What’s more, ducts leak. Let me rephrase that. Ducts leak a lot—about15%. It’s like installing a large exhaust fan in the attic to suck conditioned air out of the house and pull uncondi- tioned air in through the cracks. If radon were a valuable commodity, we could mine it this way.

And think about winter. Heating bills go through the roof, and escaping air heats the attic, melting snow and form- ing ice dams. Goodbye, heated air; hello, water damage.

You can’t make ducts and air han- dlers tight enough so that they won’t leak (don’t even think about duct tape). The least you can do is put them in a conditioned zone such as the basement or a conditioned crawlspace, or you can move the attic insulation up to the roof.

Sheet metal/stud duct

four

USING JOISTS OR STUDS FOR DUCTWORK ROTS FRAMING

Conditioned air escapes

Air handler

Ice dam

A panned stud or joist cavity is an air return that uses framing members, sheet metal, and drywall as ductwork (photo above). Why is this bad? Be- cause the air is pulled through a leaky framing cavity instead of a duct, con- taminants come along with it. The result is that air will be sucked from any leak available to equalize the pressure (drawing below). In a humid climate, the house will suck wet air into the wall cavities. If the house has a vapor barrier inside the face of the drywall, the water will stay inside the wall (air will make it through the cracks). Wall cavities are a bad place to store water.

If the stud-bay or joist-bay return is in the garage, pollutants such as car- bon monoxide or vapors from gasoline or solvents can be sucked into the living space. If the air return is in a furnace room, combustion gases can be sucked out of the flue (backdrafting).

Here’s the test: Turn on the HVAC unit and spend a romantic candlelit evening with your significant other. Burn those cloying perfumed candles; the fine soot particles in the candles act wonderfully as tracers for airflow. Next day, look for stains on the carpet at the baseboards near a stud- cavity air return. Air is being sucked into the wall under the baseboard, filtered by the carpet, and marked by the soot.

If we did plumbing this way, we’d flush our toilets into the floor framing.

15%. It’s like installing a large exhaust fan in the attic to suck conditioned air out of the house and pull uncondi- tioned air in through the cracks. If radon were a valuable commodity, we could mine it this way.

And think about winter. Heating bills go through the roof, and escaping air heats the attic, melting snow and form- ing ice dams. Goodbye, heated air; hello, water damage.

You can’t make ducts and air han- dlers tight enough so that they won’t leak (don’t even think about duct tape). The least you can do is put them in a conditioned zone such as the basement or a conditioned crawlspace, or you can move the attic insulation up to the roof.

Unwanted air sucked into house through leaky framing

The return grille delivers air as it’s supposed to, but it also draws air from unwanted sources: Poisonous fumes can be sucked in from a garage, and moist outdoor air can be drawn into the walls.

Sheet-metal backing

Replacement air

Return grille

Furnace

five

WINDOWS AND DOORS WITHOUT PAN FLASHING CREATE A WATER-INJECTION SYSTEM

There are only two kinds of windows in the world: windows that leak now and windows that will leak later. The only things that leak more than windows are doors. And the more expensive the door, the more it leaks—especially big French doors with sidelites. And sliding doors. I know, I know, I can hear the salesman already: “My windows don’t leak. They were tested at the factory.” Right, they didn’t leak at the factory. But they will leak after they’re in a house.

Air passage

Brick tie

Air inlets

Drainage mat

XPS foam Flashing

If not today, then tomorrow. Windows are like people; their characteristics change as

they age. As windows and people get old, they leak. I don’t leak now, but I will someday. Windows and doors need a de- pendable backup system: a gutter. These gutters are known as pan flashing, that thing with a back dam, end dams, and a slope toward the outside. They’re simple to install; many come in two pieces that slide together (Jamsill; 800-526-7455). Just don’t put a hole in it because a dab of silicone won’t seal the hole. Silicone is like people: When it gets old ...

six

DON’T LET BRICK WICK WATER INTO WALLS

I hate brick. No, I don’t—I love brick. I hate bricklayers. No, I hate lazy bricklayers who don’t ventilate cavities and clean up mortar droppings.

Let me rephrase that. The old way of installing brick worked. There was a 1-in. cavity behind the brick with air inlets at the bottom, outlets at the top, and a clear pathway connecting the two. Why is this important? Be- cause brick essentially is a dense sponge. When it rains, brick gets wet.

Now, let’s pause for a minute to review the second law of thermody- namics: Water moves from hot to cold and from wet to dry.

OK, back to the brick. What happens when brick is rained on? Brick gets wet, and we know that water moves from wet to dry (inward toward the dry part of the brick). Now what happens when the sun comes out? Yup, water moves from hot to cool (inward toward the cool part of the brick). If the cavity behind the brick is vented properly, the ventilation air intercepts the flow of moisture and carries it out the top of the wall. No problem.

If the cavity is vented improperly, however, water vapor is driven inward, toward the cool, dry house, and through the vapor-permeable exterior housewrap and plywood sheathing; it then condenses on the interior plastic vapor barrier. Here, the water sits and waits for mold to drink it. If the vapor barrier is leaky or if there isn’t one, the mold eats the drywall instead.

If you’re going to install brick, make sure there’s a clear cavity vented at the top and bottom. If you can’t use brick responsibly, don’t use brick.

seven

STUCCO NEEDS TO DRAIN

Two layers of felt

Stucco is a simple product. A few thin coats of reinforced mud provide a strong, good- looking protective layer for a house. The entire key to successful stucco is drainage: There must be a drainage space between the stucco and the tar paper that the stucco is installed over. This used to be easy because in the old days, tar paper was more robust than it is now: It weighed more, was thicker, and had higher rag and cellulose content. The first coat of stucco would swell the tar paper. After the stucco and tar paper dried, the tar

paper shrunk back and debonded from the back of the stucco. The resulting wrinkles formed a drainage space. Today’s tar papers and housewraps don’t debond because they don’t swell enough. Because they don’t debond, they don’t drain, and worse, they lose their water repellency over time.

To apply stucco successfully with contempo- rary tar paper, use two layers of tar paper. The first will act as a bond break, and the sec- ond will act as a drainage plane between the two layers.

eight

Stucco is a simple product. A few thin coats of reinforced mud provide a strong, good- looking protective layer for a house. The entire key to successful stucco is drainage: There must be a drainage space between the stucco and the tar paper that the stucco is installed over. This used to be easy because in the old days, tar paper was more robust than it is now: It weighed more, was thicker, and had higher rag and cellulose content. The first coat of stucco would swell the tar paper. After the stucco and tar paper dried, the tar

paper shrunk back and debonded from the back of the stucco. The resulting wrinkles formed a drainage space. Today’s tar papers and housewraps don’t debond because they don’t swell enough. Because they don’t debond, they don’t drain, and worse, they lose their water repellency over time.

To apply stucco successfully with contempo- rary tar paper, use two layers of tar paper. The first will act as a bond break, and the sec- ond will act as a drainage plane between the two layers.

WITHOUT THE RIGHT PATHWAY, CONDITIONED AIR GOES TO ALL THE WRONG PLACES

Let’s see. We duct conditioned air (supply air) to a bedroom on the second floor and place the return- air grille in some other room on the first floor. So how does air get back to the return when the bedroom door is closed? It’s sucked under the door. Accord- ing to my calculations, for this to occur efficiently, the gap at the bottom of the door should be roughly 1 ft. to prevent pressurization of the bedroom.

Why is pressurization bad? Because uncontrolled air changes are bad. If your bedroom is pressurized, conditioned (paid-for) air is being pushed through the walls and ceiling. If the pressurized air is moist, water is being pushed into the walls. Remember, wall cavities are a dumb place to store water.

Because a knee-high gap at the bottom of the door is unlikely to sell houses, we (repeat after me) ignore the problem. Air rushes under the door, is filtered by the carpet, and creates racing stripes at every door opening. Again, those romantically sooty candles enhance this effect.

The retrofit solution at my house was through- wall vents.

Through-wall vents

Return air

Furnace

Supply air

nine

AERODYNAMICALLY COUPLED GAS APPLIANCES CAN’T EXPEL ALL TOXIC GASES

More than 10,000 people visit emergency rooms each year with carbon-monoxide poisoning, and more than 500 people die from it annually. A little more than half of these cases are the result of automobile-exhaust in- halation; the rest are caused by consumer products. About 100 people die yearly because of malfunction- ing gas furnaces and water heaters.

We’ve come a long way since the caveman days, but when it comes to managing com-

In typical gas water heaters, the chimney isn’t con- nected to the top of the water heater; there’s a gap. Building scientists call this gap a bad idea. Everyone else

bustion by-products, we haven’t advanced much. Back then, we’d put a hole in our cave, light a fire, and hope the smoke would leave.

We’ve advanced from a hole in the cave to aerodynamically cou- pled gas appliances. We’ve put a pipe over the fire and stuck the pipe through a hole in the ceiling to vent smoke.

Draft hood

calls it a draft hood. Except in Germany, where things al-

ways are ordered and precise, combus- tion by-products don’t follow arrows past the draft hood, especially if your house, range hood, or clothes dryer sucks. If your house sucks, the result

Combination air-supply vent

Escaping fumes

is called backdrafting, sucking toxic gases into your breathing air.

Installing appliances this way is crazy. You should use only sealed combustion water heaters and furnaces, which are vented directly to the outside. And by

Direct-vent water heater

the way, they should have a dedicated supply of combustion air piped directly to the flame (draw- ing above right), also with no holes in the pipe.

Typical water heater

ten

THE MOST DANGEROUS THING TO DO TO YOUR HOUSE

UNVENTED GAS SPACE HEATERS AND FIREPLACES PRODUCE COMBUSTION EXHAUST THAT DOESN’T BELONG INSIDE

You’d never run your car in an enclosed space, would you? So why would you run a gas heater or fireplace in one? I’m not talking about portable space heaters, which everybody knows are dangerous in enclosed areas; I’m talking about ac- tually installing an unvented gas heater or fireplace permanently. Sure, they’re inexpensive, but the potential price tag is very high. At Building Science Corpo- ration, we call this the Kevorkian option.

Let me explain: There’s really no such thing as an unvented gas space heater or fireplace. The combustion by-products, quite simply, are vented into the room, then into your lungs and shuttled to your brain. This is bad.

When installed, maintained, and oper- ated according to the fine print on their warning labels, gas space heaters and fireplaces have a pretty good safety record. But the potential for mistakes is too great.

A window should be open when these heaters or fireplaces are on, but if it’s cold out, many people won’t open a window. Unvented gas heaters and fire- places can’t be the primary heat source, but if their thermostat is set at the wrong level, they become the primary heat source. What’s more, the room size necessary for a 30,000-Btu unit is un- fathomably large. Why in the world would you want to increase your risk of

carbon-monoxide poisoning?

Let’s revisit my cave analogy: We’ve got a fire in the cave and a hole in the ceiling for ventilation. Using an unvented gas appliance is like plugging the hole in the ceiling. By this time, we should have figured out that it makes sense to locate the fire outside the cave.

One more thing: Unvented gas space heaters and fireplaces are illegal in five states. Sealed-combustion appliances, good. Unvented combustion appliances, bad. Period.

Fine Home Building

10 Roof Goofs

Roof

Goofs

and How to Fix Them

ONE

Sloppy deck installation on new roofs and poorly prepared decks on reroof jobs are among the most common problems I investigate. Poorly fastened sheathing curls along the edges, absorbs water, and swells. This movement causes the nails to pop out. Loose nails puncture the shingles and cause leaks. Tracking down the offending nail is often harder than the repair itself. Once I find and remove the loose nail, I replace the damaged shingle. Nail pops are to be expected over time. On an older roof, they are not a big concern. On a new roof, however, nail pops are a sign of a sloppy installation and frequently are fol- lowed by more problems.

POORLY FASTENED SHEATHING

TWO

It’s surprising how often I see leaks because the butt joints between starter-course shingles line up perfectly with the joints between first-course shingles. This layout translates into a leak every 3 ft. along the bottom edge of a roof and will cause the rafter tails, wall sheathing, top plates, and drywall to get wet and rot. If the sheath- ing is not damaged, the repair is simple: Pull out a few nails, and slip a 5-in. by 7-in. piece of aluminum flashing between the starter course and the first course to cover the exposed joints. You can fasten the flashing with a single nail or with a bead of caulk between the flashing and the starter course and another bead between the flashing and the first course. If the sheathing is dam- aged, I remove several courses of shingles, replace the damaged wood, and install waterproof membrane with a properly aligned starter course.

Wrong: The butt joints between the starter course and the first- course shingles line up.

Right: The butt joints are offset. Rake drip edge

MISALIGNED STARTER COURSES

First course starts with half of a tab removed from the shingle.

Fix: Slide a 5-in. by 7-in. piece of aluminum flashing between the two courses, covering the seams. Fasten the flashing with one roofing nail placed to the side.

Drip edge

Waterproof shingle underlayment

Starter course: shingles with the tabs cut off

First-course shingles overhang drip edge by 3⁄4 in.

DUMB ROOF DESIGN

FLAWED SHINGLES

THREE

If shingles are not fastened properly, the wind can get under them, lift up the edges, and give water an easy path into the roof. Examples of lazy nailing include too few fasteners; fasteners placed too high or too low on the shingle; staples shot in vertically instead of horizontally; and not storm- nailing (six nails per shingle in high-wind areas). Always follow the nailing guidelines on the shingle wrappers, and storm-nail shingles on all roofs in high-wind areas or on roofs steeper than 10-in-12 pitch.

FOUR

Roof goofs can occur during design and during remodeling. Design mistakes include misdirected gutter spouts, valleys draining against a sidewall, bad dormer locations, chimneys that block water flow, and excessively complicated rooflines. You can’t do much about these design flaws once a house is built, but you should pay close attention to areas where roof design promotes problems.

Typical nailing pattern: four nails per shingle

Storm nailing pattern: six nails per shingle

FIVE

Nail placement is important. Nails should be driven through the nail- ing strip, just below the seal-down strip, where they’ll be cov- ered by the tabs of the next course of shingles. Exposed nails give water a way into the roof.

Seal-down strip

Nailing strip

Here’s one that may surprise you: Shingles with continuous seal-down strips can cause leaks themselves. Water that gets under the side edge of a shingle with a continuous adhesive strip won’t be able to escape and will migrate sideways until it finds an exit point, usually a joint between two shingles. This joint is where the leak begins. Valleys, chimneys,

waste stacks, and roof vents are the most likely places for water to get under shingles. These leaks are difficult to track down and repair. The solution is to use shingles with breaks in the adhesive strip. And don’t use pieces of shingle smaller than the sections between breaks. If you must use continuous- strip shingles, make sure the valley and chimney flashing doesn’t dump water where it easily can find its way under the shingles.

Removing a damaged shingle

Some roof repairs—nail pops, for example—require replac- ing single shingles. Removing the damaged shingle without damaging the surrounding shingles is the tricky part. This process is best done while shingles are cool enough not to melt underfoot and warm enough not to crack. In the sum- mer, I handle this part of the repair before 8 a.m. In the winter, I do only emergency

repairs. 1 The first step is to break

the bond created by the seal-down strips below and on the two courses above the shingle you want to remove. Breaking this bond may be difficult with some newer laminated shingles. A 50-year shingle with a 110- mph wind warranty has an aggressive adhesive bond. In these cases, I cut the adhe- sive strip with a pry bar.

2 With the bonds broken, I can remove the four nails holding the damaged shin- gle. 3 Before I remove the shingle, though, I have to re- move four more nails driven through the course above. 4 Now I can pull out the damaged shingle, slip in a new shingle, and renail all the loosened shingles.

When refastening shingles, don’t put new nails in the old nail holes; they’ll pop right out. Instead, nail next to the holes and put a dab of sealant over the old holes. While your caulk gun is handy, seal down all the loosened shingle tabs with a dab of sealant.

“BREAKING THE BUNDLES”

SIX

Some roofers make a big mistake when they load shingles onto the roof by folding the bundles over the ridge. Ironically, delivery crews call this “break- ing the bundles,” and that’s exactly what happens. Breaking the bundles can create stress fractures and separates shingle laminations, reducing the life span of a new roof. Always store shingles flat on the roof. Because cold shingles are more prone to breaking, limit cold-weather roofing to emergency repairs.

Don’t bend the shingles over the ridge. Folding bundles of shingles over the ridge can damage the shingles and diminish their life span. Lay the bundles flat on the roof, and use

a board to prevent them from sliding down the roof.

Avoid continuous seal-down strips. They may seem like a good idea, but water that gets under the shingle can’t escape. Shingles with segmented seal-down strips (top drawing, facing page) give water an exit every few inches.

Photos left, this page: Brian Pontolilo

MISPLACED STEP FLASHING

SLOPPY CHIMNEY FLASHING

SEVEN

Another common problem is improperly sized step flashing. Step flashing should be in line with the top of the shingle course being flashed and should extend down to the top of the shingle tab, about 7 in. on standard shingles or about 8 in. on metric shingles. Even properly sized step flashing can cause a problem if it is out of position. Because correctly placed step flashing covers the adhesive strip on a shingle, it won’t let the next shingle seal down in that area. Some people try to solve this minor prob- lem by moving the step flashing up an inch or so, extending the top edge of the flashing above the top of the shingle. When the top of the flashing is nailed, it transforms the top edge of the shingle into a fulcrum, and the flashing lifts up the bottom edge of the next course, causing a gap that water can enter. The installer then tries to fix the problem by nailing at the bottom edge of the flashing. This nail won’t

be covered by the next piece of step flashing and can cause a leak. Improperly installed step flashing should be stripped and replaced.

Chimney flashing is best left to the experts. Chimneys have great potential for leaks. If masons don’t set counter- flashing into the mortar or if the flashing fails, nails and caulk are not a solution. The mortar must be cut with a grinder so that carefully bent new flashing can be inserted between brick courses.

Step flashing no-no.

Nailing above the top of the shingle will cause the flashing to lift up the bottom of the next course of shingles. An extra nail to hold down the flashing is a potential leak spot.

Step flashing done right.

The flashing should be in line with the top of the shingle and nailed only

once in the upper corner. The flashing pieces should overlap 2 in.

EIGHT

A lot of roof leaks are blamed on chimney flash- ing, and for good reason. Before replacing the chimney flashing, though, spend a little time to rule out other possibilities such as a cracked mortar cap or missing chimney bricks. The most common chimney-flashing error is when roofers don’t take the time to insert counterflashing into the mortar. Properly installed counterflash- ing is bent on a sheet-metal brake, produc-

ing sharp, straight, L-shaped bends that seat cleanly in the mortar between brick courses. Chimney flashing bent without a brake is a red flag to me; it signifies sloppy detailing. When

I find a roof with poor chimney flashing, I look closely for additional problems.

ROOF-MOUNTED UPGRADES

CARELESS VALLEY SHINGLING

NINE

Leaks can be caused easily by the many roof penetrations inflicted by homeowners and remodeling contractors. TV-antenna or satellite-dish mounts, skylights, and roof vents never should be installed haphazardly, yet they often are. In the natural realm, overgrown branches can abrade roof shingles, and overly shady roofs can encourage moss growth that will degrade shingles.

TEN

I’m surprised by how many valleys have no flashing. An alarming new practice is using peel-and-stick waterproof membranes as val- ley flashing. Some less expensive waterproof membranes are warranted for only five years.

Fixing a leaky valley usu- Fifty-year shingles over a five-year membrane

ally means reshingling the entire valley. Start at the top, and remove one full shingle width from each side of the valley. Neat- ness counts a great deal here because the tidy dis- assembly of the valley de- termines how well it goes back together. www.finehomebuilding.com).

isn’t a good investment in a valley where lots of things can go wrong. The only sure way to fix a leaky valley is to reroof the entire valley. I install a waterproof membrane and W-type val- ley flashing on almost all valley repairs. (For a complete discussion of shingling valleys, go to

Closed-cut valleys Open valleys with W-type valley flashing are superior are often done wrong

No flashing membrane

Shingles don’t extend far enough onto adjacent roof. Corners are

not clipped.

Waterproof underlayment

Metal W-type valley flashing

New shingles are cut at each side of valley centreline.

By Stephen Hazlett

Get the Right Replacement!

Fine Homebuilding

Get the Right Replacement

They’re a big investment with a big potential payoff. Here’s what you need to know about types, warranties, comfort, and installation.

BY DANIEL S. MORRISON

THREE OPTIONS FOR REPLACEMENT WINDOWS

O1PTIO2N The cheapest:

REPLACE ONLY THE SASH

3If the existing frame and sill are in good condition, you can swap the sash for an energy-efficient upgrade. Remove the sash and parting stops, then install jamb liners against the sides of the window frame. The liners form a tight seal with the new sash. Many manufacturers have replacement-sash kits designed for their older frames.

OCTOBER/NOVEMBER 2004

Windows

QUICK GUIDE TO CHOOSING

First ask, “Why replace?”

Next ask, “What are my priorities?”

Almost 58 million windows are sold every year, and more than half of them are replacement windows. Thirty percent of the windows being replaced are less than 10 years old, and many are only two years old. Why are so many new windows being replaced? Many fail due to bad installation, but most windows being replaced simply haven’t lived up to homeowners’ expectations for comfort or durability.

Getting a window that matches your needs and expectations involves a series of decisions and trade-offs (see “Why replace,” right). But among the many variables—such as materials, features, and warranties—good installation is essential. A poor installation practically will

guarantee failure of even the most expen- sive high-performance

window.

There’s more than one way to replace your windows, and the most appropriate system depends on why you’re replacing them in the first place. If the old windows are rotted out or show signs of water damage, it’s critical to address the cause of the water damage in the replacement. If your old windows are merely cloudy, drafty, or hard to operate, the options widen.

Begin by choosing a type

The simplest, most common replacement- window systems leave intact the existing window frame along with the interior and exterior trim. When water damage isn’t a problem, these systems offer excellent options, including sash replacement and complete window inserts.

Water-damaged windows indicate a leak and should be removed and replaced with new window units (Option 3, p. 56). This sce-

nario entails removing the interior and exterior trim and possibly the siding and drywall. Fixing the leak and properly flashing, air-sealing, and waterproofing the new window are critical to avoid repeating the initial water damage.

Maintenance expectations

 • Vinyl or fiberglass (either clad or

extruded) is best for coastal exposure. • Aluminum-clad is durable but expensive. • Wood windows can be durable and are less

expensive.

Performance expectations

(Energy efficiency, comfort, structural) • Good: An EnergyStar sticker guarantees

minimum EPA energy-efficiency standards

(NFRC-certified). • Better: Shop for better NFRC ratings

based on your climate (see “Energy-

performance ratings,” p. 54). • Best: Use the Web to model windows for

specific (north, south) walls in your house, (Web sites, p. 56).

Durability expectations • 20+ years: A solid warranty is most

important. Other expectations will give

way, particularly budget expectations. • 10 years or less: Comfort, maintenance, or

aesthetics may trump warranty.

Cost: $260

National average list price based on a 3-ft. by 5-ft. opening; aluminum-clad sash; low-e, low-SHGC, argon-filled, double-hung replacement window.

Important installation details

● Easy installation.

● Energy-efficient upgrade. ● The finished product may be

Pros

Cons

Measure according to manufacturer’s specifications.

Check that window frame is square.

Check that sill is flat, not crowned.

Jamb liners and sash must match slope of sill precisely; kinks allow air leakage.

Finish air-sealing with foam plugs at top and bottom of jamb liners.

● Maintains the window’s original glass area.

● No need to disturb existing casings.

● Least-expensive replacement- window system.

leakier than Options 2 and 3.

● Hard to fit properly in old openings that may be out of square or crowned.

Window samples courtesy of Jeld-Wenn, Loewen, and Marvin

ENERGY-PERFORMANCE RATINGS: LOWER IS BETTER

Because two windows that look exactly alike can perform differently, the National Fenestration Rating Council provides third-party performance ratings for windows and doors so that consumers can have an apples-to-apples comparison. The invisible parts of a window combine to boost performance, energy efficiency, and comfort.

Gas filling: Like air, argon is nontoxic, clear, and odorless, but it’s a better insulator. The optimal gap between panes of glass is 1⁄2 in.

Low-emittance (low-e) coatings are nearly transparent metal films. All low-e coatings bounce radiant heat back to you in the winter. Most reflect the sun’s radiant heat in summer, too.

Double-glazing improves U-factor: Two layers of glass are standard. Triple-glazing is a good idea in very cold climates. Impact- resistant storm glazing is required in many coastal areas.

Solar heat-gain coefficient (SHGC): Percentage of the sun’s radiant heat getting into your house. Low numbers (0.4) mean low AC bills. Medium and high numbers (0.5-0.7+) can work in colder climates.

U-factor is the inverse of R-value: Sum of all U-factors (glass, frame, and sash) in the window unit. Smaller numbers (0.35 or less) mean greater energy efficiency and comfort.

Warm-edge spacers: Specialized rubbers, foams, and plastics that improve U-factor and reduce condensation.

Additional performance ratings such as air leakage, water leakage, and impact performance may be required by local codes.

Condensation resistance: Quantifies all of the above features to predict the likelihood of condensation. This 0-100 index is intended more for comparing different windows than as a performance guide.

Some companies even offer energy-efficient historic reproductions that closely match orig- inal windows (see “Historic houses don’t need leaky windows,” p. 57).

Frame and sash choices: Think aesthetics, insulation, durability

Whichever option you choose, you have to decide what materials best fit your needs. If you like wood windows but don’t like scrap-

ing and painting every 10 years, exterior cladding of vinyl, fiberglass, or aluminum is an excellent choice (photos pp. 56-57). They’re all durable and require no painting. Window manufacturers offer aluminum cladding in up to 50 stock colors with custom-color matching, whereas vinyl and fiberglass cladding are generally available in white and beige; fiberglass can be painted. Keep in mind that you can step down in price by choosing

all-vinyl windows. They can be up to 40% less expensive than comparable aluminum-clad wood windows.

Because the frame and sash can make up almost a third of a window’s total area, their materials play an important part in both com- fort and durability. Insulating capacity (mea- sured as U-factor; lower is better) is important in cold climates; in hot climates, keeping heat out of the house takes precedence. Because

12The easiest: INSERT A FRAME AND SASH

3The most common system comes as a complete unit that slips into the existing window jambs against the exterior (or interior) window stops. Use low-expanding foam to seal the perimeter gap and ensure an airtight installation.

OPTION

Photo bottom right: Randy O’Rourke

radiant heat is much more powerful than oth- er forms of heat transfer, it’s more important to keep radiant heat out with low solar-heat- gain coatings than to focus on U-factor.

Finally, consider how the frame and sash materials will stand the test of time. Some very good windows are made with vinyl, and some very bad windows are made with vinyl. The same goes for wood and aluminum. Your durability decision shouldn’t be based

solely on material; quality of manufacture is equally important.

Look for ratings, and buy for the warranty

It’s important to realize that when you remove a window from a wall, you’re left with a large hole in your house. You should plug that hole with something that will look good, perform well, and last long.

To increase the odds of meeting your com- fort and durability expectations, you need to read the National Fenestration Rating Coun- cil’s (NFRC) energy-performance label and shop for the best warranty. “You can’t trust your eyes when you’re shopping for win- dows,” says R. Christopher Mathis, a build- ing consultant and former NFRC director. “Two windows that look exactly alike can perform very differently.” Different glass

COMFORT COSTS LESS

I was sitting on the couch in the little window bay of my liv- ing room watching Norm on PBS like I do every Saturday. It was springtime at The New Yankee Workshop, but outside my windows, it was -10°F, and I was cold. I could have put on a sweater, as my wife does, but I did what most guys do: I reached for the thermostat. I was astonished to see that it read 70°F. How could that be? Seventy degrees is warm, so why was I uncomfortable?

Because heat loss from radiation is much more drastic than other types of heat loss, it gets worse as you get closer to the cold (or hot) object.

Old or cheaply made win- dows can suck the heat from you in winter, or turn your living room into a microwave in summer. Effectively, this makes the comfortable por- tion of a room smaller because you’re uncomfortable if you sit near the windows. And if you’re uncomfortable, you reach for the thermostat.

Good windows enlarge a room’s comfortable area, which means less reaching for the thermostat, less work for your furnace or air conditioner, and lower utility bills.

“Seventy degrees is warm, so why was I uncomfortable?”

Pros

Cost: $530

National average list price based on a 3-ft. by 5-ft. opening; aluminum-clad sash; low-e, low-SHGC, argon-filled, double-hung replacement window.

Important installation details

● More dependable energy ratings than Option 1 because the sash and frame are tested as a unit.

● Less invasive than whole- window replacement. The process takes one hour.

● Won’t disturb existing casings, siding, or wall coverings.

● Reduced glass area and bulkier look due to an additional window frame.

● Smaller opening may violate fire-code egress requirements.

● The most expensive method, considering only materials.

Cons

Verify opening for square; measure accordingly.

Air-seal the perimeter with low-expanding foam, not fiberglass batts.

Fill header and sill extensions with low-expanding foam insulation.

Protect against wind-driven rain with highest-quality sealant at exterior stops.

SASH AND FRAME OPTIONS: CHOICES DEPEND ON COLOR, COST, AND DURABILITY

LEAST EXPENSIVE

Vinyl won’t corrode

Clad or extruded, vinyl is a no- maintenance option for coastal areas where aluminum may corrode over time. U-factor: 0.33; with insulated cavity: 0.27 Colors: Whites, beiges Relative cost: Least- expensive option; roughly 40% less

than aluminum-clad.

Wood requires a finish

Wood windows are available factory- primed, but you should scuff and reprime the surfaces before painting. With regular maintenance and good paint, wood windows ought to last a long time.

U-factor: 0.33 Colors: Any paint or stain color. Relative cost: More expensive than vinyl.

coatings, gas fillings, and spacers between glass panels are impossible to differentiate visually; they can be verified only through laboratory tests. If you want the assurance of energy efficiency from an independent third party, you need to look for the NFRC label.

NFRC ratings make comfort expectations predictable; a solid warranty makes a win- dow’s service life predictable. Warranties reflect how confident a company is in the durability of its product. The top window companies offer 20/10 warranties: 20 years on the window seal and 10 years on everything else (frame, sash, and hardware). That’s a good benchmark.

Fiberglass is the most durable

Stronger than vinyl, fiberglass can be extruded into slimmer cross-sectional profiles, making it a good choice for option 2. Also available with wood interiors for a warmer look. No maintenance requirements, but fiberglass can be painted. U-factor: 0.33; with air cavity filled: 0.27 Colors: White, but it can be painted any color. Relative cost: Costs more than wood or vinyl.

Prorated warranties and exclusions such as nontransferability make it hard to judge how long even NFRC-rated windows will per- form well.

And beware of a lifetime warranty. If name brands such as Andersen, Marvin, and Loewen can give you only a 20/10 warranty, how can a no-name window company offer more? The answer: exclusions.

Can Mom and Pop compete with Marvin and Pella?

There are thousands of window manufactur- ers in North America. Smaller companies can produce a less-expensive product that rivals

ENERGY-EFFICIENT WINDOW INFO

● www.efficientwindows.org ● http://windows.lbl.gov ● www.eere.energy.gov/consumer

info/energy_savers/windows.html ● www.rehabadvisor.com ● www.nfrc.org

12The best: COMPLETE WINDOW REPLACEMENT

3When water damage is occurring, the window and rotten framing should be replaced and the source of the leak tracked down and stopped. A rotted window may be the symptom, not the source, of the leak. Complete replacement is best because it allows you to integrate the new window fully into the wall with new head and pan flashings, low-expanding foam,

OPTION flexible flashing membranes, and high-quality sealants. 

MOST EXPENSIVE

Aluminum-clad comes in many colors

If you want to change the color, repaint with a metal bonding enamel after proper surface preparation.

U-factor: 0.33 Colors: Some companies have up to 50 colors; many will custom-match colors. Relative cost: Most expensive option.

the windows made by big manufacturers, but they usually can’t provide the same warranty. Small companies don’t have the same risk- management resources that the name brands have, so some risk is passed to the consumer.

When shopping for the warranty, make sure that the window manufacturer will be there when you need it to be. Ask how long the manufacturer has been in business. Is a two-year-old manufacturer offering you a 20- year warranty? Does the company have a toll- free telephone number, and if so, is there an actual human being to answer your call?

You may decide that a prorated warranty is worth the gamble for the lower price, but stay

away from nontransferability clauses; they don’t make sense. How can the transfer of homeownership affect the service life of a building component?

Replacement windows are a big investment in money, energy efficiency, and personal comfort. It’s not worthwhile to skimp on untested or falsely warrantied windows. If the window company won’t bet on its product, why should you? 􏰀

Daniel S. Morrison is an assistant editor at Fine Homebuilding. 

HISTORIC HOUSES DON’T NEED LEAKY WINDOWS

Many window manufacturers offer historic retrofits (as illustrated in this display by Marvin) that will be more likely to pass the historic commis- sion’s review panel. Andersen’s Woodwright series of replacement windows features wood jamb liners and traditional sash details to blend gracefully into a historic house. For more information on preservation guidelines, visit the National Park

Service Web site at www2.cr.nps.gov. (Also, see FHB #161, “Restoring Window Sashes,” pp. 84-89.)

Cost: $446

National average list price based on a 3-ft. by 5-ft. opening; aluminum-clad sash; low-e, low-SHGC, argon-filled, double-hung window.

Important installation details

● Most versatile because you can change the window’s size.

● The most energy-efficient system because the window is fully integrated into the wall.

● Most durable because you can upgrade the flashing details.

● The most invasive method.

● The most difficult method.

● The most expensive method, considering labor.

Pros

Cons

Protect against wind-driven rain with head flashing and high- quality sealant along top and side flanges; uncaulked bottom flange allows water to escape.

Ensure against rot with pan flashing.

Integrate flashings shingle style into building paper.

Maintain air seal with low- expanding foam along inside perimeter.

Choosing The Right Dishwasher

it’s important to ask yourself exactly what you want

June 21, 2010 - Chris Bennion - Coast Wholesale Appliances

Appliances have come a long way in 20 years. Just looking at a new dishwasher and its long list of features can leave the consumer overwhelmed. These days, it’s important to ask yourself exactly what you want from your dishwasher so you can zero in on the best fit for you.

Start with general questions like:

• What colour do I want (Stainless Steel, Black, Panel Ready)?
• How many loads of dishes do I do in one week?

A common mistake when buying a new appliance is that consumers feel they can walk into a store, look at 4 or 5 different options and be done. Unfortunately, these days you will walk into the store and have 30 to 40 different options. By answering some general questions, you can quickly narrow these options down, saving you a lot of time.

The next step is to look a little closer and determine what features you actually need. Will you require a dishwasher which has a Sanitize cycle? Or perhaps a dishwasher that has an upper rack only wash?

Dishwashers today have lots of features to explore. You can research these features on the internet or discuss them with your sales associate – they are trained to help you find the specifics of what you require.

Examples of other questions you might ask yourself:

• Do I need a dishwasher that has a delay start?
• Do I need a dishwasher with auto sensing wash technology?
• Do I want a Domestic or Imported brand (i.e. Miele, Asko).

Something really important to consider is how often you are running your dishwasher. Make sure to let your salesperson know your usage requirements as not all dishwashers are built for heavy extended usage. When you using your dishwasher more than once a day you primarily want to look at the $1000.00 and above price level if you want a good dependable dishwasher that can handle the work-load.

If you have young children at home that like pushing buttons, consider a dishwasher that offers a child lock feature. This feature disables all the buttons so your toddler can’t turn off the dishwasher mid-cycle, or turn it on when it’s empty.

If aesthetics are important, you may want to consider a model with integrated controls. Integrated units are slightly different from regular dishwashers in that all your controls are located on top on the dishwasher door. This hides them away, leaving a sleek looking dishwasher with no visible buttons.

Having heavily-soiled dishes on frequent basis may affect what type of dishwasher you need. Some foreign dishwashers are not designed for typical North American use; putting dishes into the dishwasher without scraping and rinsing them first. Brands like Maytag, Samsung and Jenn-Air come with a Macerator that is designed to handle particles of left-over food residue. This doesn’t mean that these dishwashers have a Garburator (for grinding up food) – a common misconception among consumers. A Macerator, however does help by preventing grimy residue on the cleaned glasses and plates.

Before buying your dishwasher, always double check your dishwasher cabinet measurements. Most dishwashers are designed to handle height restrictions, but if you have recently installed hardwood flooring, you may have issues. Hardwood underneath the dishwasher can affect the height, making most dishwashers ‘too tall’ to fit. There are dishwashers that are designed to be a little shorter in order to accommodate people who use wheelchairs or have limited mobility. Check with your sales associate to find out which options are available to you.

Consider whether you want a Stainless Steel or Plastic interior. Most people currently have plastic interior dishwashers, however, the disadvantage is that plastic interiors change in colour over time. Plastic interiors also provide a surface tension that water drops can cling to – this is why water dislodges from the roof of the dishwasher when you open the door after your dishes have gone through the drying cycle. Stainless Steel interiors will never change in colour and also provide little to no surface tension for water, forcing it down the door or falling off the top of the dishwasher roof. The Stainless Steel interior also acts like a sound barrier making it a much quieter dishwasher.

Finally, make sure you consider getting an extended warranty with your dishwasher. The dishwasher is often your most used kitchen appliance and therefore is more subject to break-downs. Consumer Reports states that of the repairs that happen between 3 to 4 years in your dishwasher’s lifespan, at least 22% require major repairs. Just one service call outside of the manufacturer’s warranty can cost you nearly $60.00, and that’s just for someone to come take a look. Add parts and labour and things can get expensive fast. Most retailers provide warranty plans, and most have onsite coverage. I always recommend that my customers get a warranty on their dishwasher. This does not mean that dishwashers are ‘built poorly’, or ‘designed to break-down’ – this is not accurate at all. Simply put, your dishwasher is a delicate piece of machinery that you want to protect in case anything does go wrong, whether that be from daily wear-and-tear or other circumstances.

This article is provided by Coast Wholesale Appliances. For more information, please visitwww.coastappliances.com.