When a retrofit window is installed without adequate space between the retrofit frame and the opening, seasonal expansion and contraction can cause distortion of the window frame and failure of the weather seal, resulting in water leakage into the wall and window cavities.

If the window is not squared or level, the sash will not close properly, and the weatherstripping may not be able to provide an adequate weather seal.

Failing to support the retrofit frame property. particularly across the bottom, can cause the frame to contort and allow the sill to sag.  This will result in such problems as rough sash operation, incomplete closure, leakage of air and water around the sash, failure of the perimeter caulk and damage to the insulated glass seal.

All anchors (screws & nails) must be non-corrosive to resist stains, oxidation and corrosion.  Screws should be plated, and fasteners should conform to the window manufacturer's specifications.
Common errors include using anchors that are too small or too short and either not installing them deep enough or driving them into the wrong substrate. Often the result is a window frame that sags in place, contorts, pulls loose in the wind, and leaks.

A manufacturer's Guarantee will not protect you against a faulty installation.

Anchoring the top of the retrofit window (the fin or head jam) to the header (which expands and contracts) will lead to a distorted window frame, failed seals and hampered window operation.

When insulating the cavity surrounding the retrofit window, use of expanding foam or tightly packing mineral fiber can apply excessive pressure to the window frame, distorting the frame and impeding smooth operation of the sash.

Improper or nonexistent flashing or sealant can allow moisture to permeate the structure.

Sometimes removal of the old window results in a cut or tear to the moisture barrier.  Correct techniques here are fundamental.

The highest quality window can be installed perfectly square, level and plum, and secured with the utmost precision; but if the exterior seal fails or chemical damage occurs, the entire installation is compromised. Using the wrong caulk or inadequate caulking can result in moisture penetration and water damage, or corrosive damage from a chemical reaction.

Placing dissimilar metals (such as aluminum and steel) into direct contact with each other can cause accelerated corrosion and premature failure of the weather seal.

A manufacturer's Guarantee will not protect you against a faulty installation. For a wise and safe choice and an installation you too can be proud of, get the factory trained, zealous installers of "The Window Specialists- 1 (800) 464-9499 for a free no-obligation Estimate.