Why wood windows?

Plenty of good reasons.

Home & Garden Magazine, August 2008
Why wood windows?
Why would you choose wood-framed windows? After all, they need a paint job every couple of years, they get stuck in the tracks, they’re hard to clean and harder to repair or reglaze, they’re expensive–in general, they’re a pain, right?

Not any more. Thanks to a host of product innovations, today’s wood windows are more reliable, durable, and versatile than you might expect. Streamlined hardware, smooth-working rigid plastic tracks, snap-out muntins, low-maintenance cladding, and a new generation of glazings are among recent improvements.

Besides natural warmth and beauty andgood thermal properties, a wood-framed window can lend a distinctive style to a house fa*eade and interior. Major manufacturers build windows in a wide range of standard sizes and shapes, including squares, octagons, trapezoids, bull’s-eyes, semicircles, and more. If you have an odd-size opening or a special shape in mind, you can custom-order from a major firm or from a small specialty shop (for leads, look in the yellow pages under Windows –Wood).

windows and door manufacturingAs you might guess, wood windows aren’t cheap; a double-glazed 4- by 6-footer with fixed center pane and two openable casements, like the one being installed at top, can cost up to $600. But if you plan to build or remodel, they’re worth a look.

Most wood windows are made of ponderosapine (“western pine’ in some brochures) or Douglas fir. To extend the wood’s life, it is factory treated with a water repellent preservative before assembly. Depending on your order, the exposed wood may be bare or primed; you do the final staining or painting.

Wood is a far better insulator than vinylor aluminum. But it is sensitive to changes in humidity and temperature, swelling as it absorbs moisture, contracting as it dries out. This ebb and flow occurs constantly, causing paint, putty, and other surface treatments to deteriorate. Left unprotected, wood will gradually check and rot.

To make a wood window last, you need torestain or repaint every few years–a neck-straining job if you have windows with muntins. Over time, accumulated paint on sash channels or sills can make windows harder to open and close, and may lead to air infiltration.

As an alternative, manufacturers developed clad models to keep the elements at bay: all exterior wood is sheathed by a thin coating of vinyl or aluminum, impervious to ultraviolet light. This allows you to skip painting and still enjoy the wood’s qualities indoors.

But cladding has its drawbacks. For starters,it increases your cost. Color choice is limited–typically white and a few shades of brown and gray. If those colors don’t suit you, buy a brand with a baked enamel cladding that can accept paint.

When shopping, ask about the makeup of the cladding. For greater strength and durability, buy a heavy-gauge extruded– rather than rolled–material. In extremely cold conditions, avoid vinyl cladding: it can turn brittle and crack.

Though many of the larger window companies are based outside the West, they market extensively through home centers, building supply yards, or name-brand dealer networks–there’s no shortage of choice. Often the window you order is built at the plant, then shipped to the dealer, where it’s readied for installation before it’s delivered to you. If you don’t like that idea, you can find companies that manufacture closer to home; there’s less risk of damage to the product in transit, and you may find a dealer who’s more responsive if problems arise later.

There’s one important hitch: all manufacturers do not make windows in identical sizes. Say you have a 4- by 5-foot opening; you may find only one window company sells that size as “standard.’ If you can live with that brand and style, fine. But if you prefer a different brand, you’ll likely have to alter the rough opening or custom-order.

Standards and options: what to look for in glazing, working design, grilles

In most styles, you can choose between single, double, and triple glazing. Double- and triple-glazed windows have a sealed airspace between panes; the air acts as an insulator and minimizes condensation.

(Triple glazing is seldom cost efficient,except in coldest climates. Instead, consider double-glazed windows with interchangeable storm windows and screens.)

Also available is a system with one fixed and one removable pane; the second pane fits into the frame with quick-release finger locks. The removable pane can be clear, tinted, or low-emissivity glass. Advantages? It’s easier to replace single glazing than double if the window gets broken. You can also fit miniblinds between the panes if light and privacy are both important, as in a bathroom. Disadvantages? Some homeowners we interviewed complained of condensation between the panes. You have four sides of glass to clean (the panels are not airtight). And this system is relatively expensive.

You can also choose regular glass or low emissivity glass. Construction is important. Each pane should be fully sealed in the sash, with thermal breaks–additional enclosed airspaces–built into the frame. Weatherstripping should provide an uninterrupted seal around the window when it’s closed. Also consider functional design. For example, newer casement windows have sliding pivot arms so they can open 4 or more inches in from the corner, for easier cleaning of the outer pane.

You’ll find double-hung models that let you take the sash out of the channel. There’s even a “tilt-turn’ model that opens from the side and from the bottom, using a German-made hinge mechanism. Divided-light windows have several individual panes; they’re attractive and traditional, but costly. For a similar look with one large pane, you can opt for snap-in grilles in vinyl or wood. They’re inexpensive and ease cleaning chores–though the wood ones need occasional repainting.

Checking energy performance

To get some idea of a window’s energy performance, take the time to check its specified R- and U-value ratings.

For retarding heat flow, single glazing israted about R-1. Double-glazed models run R-2 to R-2.5. Triple glazing gives you roughly R-3.5. The low-e glazings top out at nearly R-4.5. (A typical fiberglass-insulated 2-by-4 stud wall rates R-11).

For overall energy efficiency, a U-valuerating of .5 or less is pretty good. Single-glazed windows (with 1/8-inch glass) rate around 1; double-glazed models go as low as U-.25.

Note: the R and U values aren’t established by a single independent agency, such as Underwriters’ Laboratories. Some manufacturers do their own testing.

Costs vary widely with size, style, options, and manufacturer

Compare prices as you shop, and you’lllikely hear such comments as, “Our double-hungs cost less than theirs, but our casements cost more.’ Here are some rules of thumb we’ve discovered:

Standard-size single-glazed windows costroughly $7 to $15 per square foot; double-glazed, $15 to $20. Snap-in grilles add about $2 to $4 a square foot. If you opt for true divided-light windows, you’ll pay $25 to $30 per square foot. Custom sizes cost up to twice as much.

Remember, it costs more to install roundtopor odd-shaped windows, since additional framing and workmanship are required; ask your contractor.

Can you install the windows yourself?

In general, you need to provide the company with the height and width of the window openings and the thickness of the wall. Most firms will send a representative to your house to take measurements and discuss options–but sometimes only after you pay a visit to their office.

Can you install a window yourself? Yes, if you’re a fairly experienced carpenter, have some help, and buy the window fully flanged to fit in place. Be very sure that the rough opening is sized to the window’s exterior dimensions, that the frame is plumb and level all around–this may involve some shimming–and that you caulk and seal the frame before you close up the wall. But be advised: do-it-yourself installation may invalidate your warranty, and not all window firms provide step-by-step instructions.

Throughout the West, you’ll encounteregress codes that are enforced by building inspectors. The codes may spell out, for example, the minimum amount of glass acceptable in bedrooms (in some communities, 5.7 square feet) and set standards for placement (sill no more than 44 inches above floor). Also, energy codes govern the percentages of glass-to-floor area in a house. Make sure your plans jibe with the codes before you proceed.