How to Install Vinyl Sided Window

FEATURES OF VINYL WINDOWS

• There are differences in the quality of vinyl windows just as there are in any building product. Some of the features that distinguish different windows include:
  
  
• Vinyl formulation. Early vinyl windows had problems with extreme expansion and contraction during temperature swings, as well as fading, peeling and cracking when exposed to direct sunlight. Manufacturers have switched to PVC without plasticizers (called UPVC) to minimize movement and developed additives that help resist the ultraviolet rays in sunlight.

• Frame design. Vinyl window frames may be screwed together like aluminum windows, or welded at the corners. Windows with welded frames tend to be sturdier, as well as more energy efficient, since air is sealed inside.
  
  
• Glazing. Modern vinyl windows are available with the same high-tech glazing used in top-of-the-line wood windows–insulating glass with low emissivity (low E) coatings, and filled with argon gas to increase insulating value.
  

• Many states have adopted an energy efficiency rating system for windows developed by the National Fenestration Ratings Council (NFRC). The NFRC rating lists the U-value for the overall window, not just the glass. The lower the U-value, the more energy efficient the window.
  
  
• If your house has older wood double-hung windows, vinyl is a good replacement choice and a reasonably easy do-it-yourself project. You don't have to remove your old windows entirely, because vinyl replacement windows are made to fit in the sash opening.

From the Estimator's Encyclopedia,
© 1993, Greg Brooks Communications

MEASURING VINYL WINDOWS

• The most important part of the installation procedure comes before you even have your windows. It is critical that you measure your old window opening properly and accurately.
  
  
• Vinyl windows are custom-built and can't be returned if they don't fit. Most are manufactured in 1/4" increments, and you'll want to get the closest fit possible.
  
  
• Manufacturers' measuring instructions vary, but the following procedures are typical.
  
  
• To measure the width, raise the lower sash and measure the jamb-to-jamb width in three places–near the top of the window, at the middle and close to the bottom.

• To measure the height, measure from the head jamb to the sloped sill just past where it meets the inside window stool.
  
  
• Don't assume that all your windows are the same size. Draw a rough sketch of your house and number each window you plan to replace, then measure each of them separately.

INSTALLING VINYL WINDOWS

• To install a vinyl replacement window, first remove the old sash. A traditional double-hung window has two sets of removable stops. All have an inside stop that holds the lower (inner) sash in place and a blind stop that separates the two sashes. The outside stop is nailed to the edge of the sash and is not removable.

• Pry off the inside stops carefully so you can reuse them. Cut the sash ropes and remove the lower sash, then pry out the blind stop and remove it. Remove the upper sash.
• Set the replacement window in the opening. It should fit snugly between the stool on the inside and the outside stops of the old window on the outside. If the new window is narrower, you may need to nail a strip of wood to the jamb to fill the gap between the window and the outside stop.
• Some vinyl replacement windows have sloped extrusions on the bottom that match the sloped sill of your old window; others are flat. If the bottom of your new window is flat, you may be able to use a piece of lattice or door stop as a support for the front edge of the window.
• If not, you'll have to rip an angled support. To do so, set the window in place in the opening, and measure the gap between the front lower edge of the window and the old sloped sill.
• You can make supports for all your windows at one time. Plane the edge of a board at an angle that roughly matches the slope of the sill, then rip a strip of wood to match the gap. To install the support strip, cut it to length and nail it in place directly beneath the point where the front edge of the new window will rest.
• Center the window in the opening. Use a carpenter's square to make sure the window is square, then shim the sides of the window directly behind the predrilled screw holes in the jamb. Screw the window in place through the side jambs, then replace the inside stop.
• Go inside and check the window to make sure it operates properly. Then go back outside and run a narrow bead of caulking all around the window to seal the gap at the outside stop.