sliding and double-hung windows pros and cons & Weatherstripping

Sliding windows are easy to operate, maintenance-free and easy to clean. On the other hand, since they have very few components there is very little to go wrong with them; but they aren't a good option from an energy efficiency standpoint.

Sliding windows are prone to air leakage; their felt and pile weatherstripping tends to become loose with time.

Gliding / horizontal sliding windowSliding windows Advantages

Gliding, that is, horizontal sliding windows are increasingly popular, largely because they are easy to open, close and clean.

Sliding windows (including double-hung windows) have few components; they have no pulleys or springs, just small wheels inside the track. That makes them very low-maintenance units.

They are also very easy to use: you just have to unlock them and then slide the window, and do the opposite to close. Besides, you can open them as far as needed, and you can easily fit them with flyscreens. 

Double-hung windows
Double-hung window weatherstripping

Sliding and double-hung windows vs. casement windows
Sliding and double-hung windows haven't a compression sealing, which makes them them more prone to leakage and less energy-efficient.
»» They also lack the ventilation capability of casement windows

sliding windows aren't energy efficient

Sliding windows lack the compression seals of casement, hopper and awning windows; their design makes them potentially more leaky and less energy-efficient.

Their felt and pile weatherstrips tend to become loose with time. It's not easy to find weatherstrips in hardware stores, and the installation is a tricky task

Original weatherstrips are embedded in the window structures, which makes their improvement and replacement difficult.

Pile weatherstrip with plastic Milar fin centered in pile can be a good weatherstrip, but it's not easy to instal (it may be best to hire a professional).

wood Sliding windows weatherstripping materialsV-Strip Weatherstripping

In wood sliding windows, use metal V-strips; that's the best for durability.

The application of these V-strips is similar to that of double-hung windows. See: Double-Hung Windows Weatherstripping

Alternatives to V-StripsWeatherstrip foam

If you you're not planning to open your windows during the heating season, consider using a simple adhesive-backed tape/foam on the sash channels; temporary weatherstripping makes sense, if you don't intend to use the window...

Consider adhesive tape foams. They are cheap and effective.

Tape Application

Before applying adhesive tapes to the sash channels of sliding windows, clean the surfaces where they are going to be applied. Pay attention to the instructions on the adhesive-backed tape/foam package. To make a tight bond, apply pressure all over the adhesive, using your finger...

See also:
Weatherstripping Materials

Double-Hung windows

Double-hung windowDouble-hung windows open vertically by sliding the sash down or up. They are very popular, partly due to their aesthetics.

Like other sliding windows, they are unobtrusive and easy to open and to clean.

But they have the same disadvantages of other sliding windows; the non-compression sealing makes them prone to leakage; also - unlike casement windows - they can't be use to deflect breezes, in cooling strategies.

Double-hung window weatherstripping

For a durable and effective wood double-hung window weatherstripping, consider V-strip materials. There are other alternatives, cheaper and easier to install, but they have a shorter lifespan.

V-strip WeatherstripsWeatherstripping Bronze

Typical V-strips (also called V-shape tension seals and V-channels...) for double-hung windows are made from metal (bronze, aluminum, copper and stainless-steel), vinyl or polypropylene, and are commonly sold in rolls.

Many modern V-strips are self-sticking (they have a peel-and-stick backing) and are easier to apply than other V-strips. Most professional glaziers use vinyl V-strip on the side jambs, and bronze V-strip on the top sash. Propylene Foam Weatherstrip


Clean carefully the surfaces where the weatherstrips are going to fit. Use soap and water, and make sure that the surfaces are dry before beginning the application. Remove any residues in the jambs and top sash. You may need to scrape them, or to plane the sides.

Applying V-strips to side jambs

Cut two pieces of V-strip, according to the side jambs height; cut them 1" longer than the height.

Peel the back of the foam (or vinyl or metal…) and firmly press the adhesive side onto the jamb.

Typically, you should also use nails to secure the weatherstrips. Test the sash to see if it works smoothly.

Applying V-strips on the top sash of the double Hung windowsDouble Hung Windows

Cut a V-strip (bronze…) peace taking into account the width of the sash. It should match that width.

To install the V-strip on the top sash, raise it 3" to 4" (8-12 cm). Then peel the back of the V-strip (if you are using self-sticking strips) and press it firmly into the back of the top sash. Pay attention: the V should open facing up. Only so it will compress and seal the window.

See also:
Residential window prices and paybacks
The best windows for cold, mixed and hot climates
Clerestory Windows for Ventilation and Passive Solar Buildings
Casement Windows Energy Efficiency
Aluminum vs Vinyl vs Fiberglass vs Wood vs Clad window Frames and Sashes
Window sizing and placement
Top Double and Triple Pane Window Manufacturers




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