Storm Windows USA · Installation library

Measuring & Installing a Direct-Mount Low-E Panel

A direct-mount panel fastens to a suitable existing sash or frame. It is a fixed glass assembly, with a nominal 0.865-inch frame face and 0.500-inch frame depth. The seal adds to the installed projection. Choose this design when a fixed panel and screw removal suit the opening.

Before you begin

Use the order-specific installation drawing supplied with your window. This guide explains the workflow; your selected mounting detail controls final dimensions, fasteners, sealants, and clearances. Handle glass with support and suitable protection. Preserve any required emergency access, and have damaged or difficult-to-reach openings reviewed by a qualified installer.

Have these ready

  • Tape measure marked in 1/8 inches
  • Level and square
  • Specified attachment screws and screwdriver
  • Specified closed-cell foam seal
  • Gloves, eye protection, and support for the glass panel

Step one

Measure for the mounting method

Record the opening width at the top, middle and bottom, and height at both sidesTop widthMiddle widthBottom widthLeft heightRight heightMeasure at the surface where the frame will mount.
Opening measurements for review. Diagram is illustrative; mounting details determine the finished frame size. Record all readings, including differences.
  1. First identify the continuous surface where the frame will attach. Check that it can securely accept the specified fasteners.
  2. For an initial quote, send width, height, quantity, and ZIP. Identify whether these are opening readings or intended finished panel dimensions.
  3. Production uses the approved finished tip-to-tip frame size. Do not automatically apply a recessed-frame deduction or an overlap allowance from another product.
  4. Check hardware travel, clear glass area, mounting-face width, and corner squareness. Arched or irregular shapes need a reviewed drawing before fabrication.
Start your quote with width, height, quantity, and shipping ZIP. Keep opening dimensions and finished frame dimensions clearly labeled so an allowance is never applied twice.

Installation, step by step

  1. 1

    Confirm the finished dimensions

    Match the actual panel dimensions and mounting plan to your approved order. This frame attaches directly to the existing surface; it is not a compression-fit insert.

  2. 2

    Prepare the mounting face

    The attachment surface should be sound, clean, dry, and suitable for the specified seal and screws. Resolve loose paint, deterioration, or uneven areas before fitting the panel.

  3. 3

    Dry-fit and check clearance

    Support the panel against the intended sash or frame. Confirm coverage, clearances, fastener locations, and the appearance from both sides. Do not use the glass to force a frame into alignment.

  4. 4

    Apply the specified foam seal

    Install the closed-cell foam seal on the mounting interface according to the approved detail. Keep it continuous and avoid stretching or leaving gaps at the corners.

  5. 5

    Fasten without distortion

    Support the glass while installing the specified screws through the frame attachment points. Tighten evenly to seat the seal without bending the frame or stressing the glass.

  6. 6

    Inspect the completed panel

    Check seal contact and clearances. Confirm any required primary-window movement and access. Removal of this fixed panel requires releasing its mounting screws while safely supporting the glass.

The finished-installation check

  • Finished panel size matches the approved drawing.
  • Fasteners engage the intended sound mounting surface.
  • Foam seal makes even contact.
  • Frame is flat and glass is not stressed.
  • Access requirements were considered before choosing a fixed panel.

If something does not fit

There is not enough mounting surface

Stop and review a different attachment detail or system. Do not move screw locations into weak or unsupported material.

The frame pulls out of shape

Check the mounting face and fastener tension. Do not pull an uneven surface flat by overtightening against glass.

You want frequent ventilation

Compare an operating interior or exterior storm before ordering a fixed screw-mounted panel.

Windows covered by this guide

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