Three Options for Replacement Windows

Experienced MA window replacement home improvement contractor

1 – The cheapest:   REPLACE ONLY THE SASH

If the existing frame and sill are in good condition, you can swap the sash for an energy-efficient upgrade.   Remove the sash and parting stops, then install jamb liners against the sides of the window frame.  The liners form a tight seal with the new sash.  Many manufacturers have replacement-sash kits designed for their older frames.

Important installation details

  • Measure according to manufacturer’s specifications.
  • Check that window frame is square.
  • Check that sill is flat, not crowned.
  • Jamb liners and sash must slope of sill precisely; kinks allow air leakage.
  • Finish air-sealing with foam plugs at top and bottom of jamb liners.

Pros

  • Easy installation.
  • Energy-efficient upgrade.
  • Maintains the window’s original glass area.
  • No need to disturb existing casings.
  • Least expensive replacement-window system.

Cons

  • The finish product might be leakier than Options 2 and 3
  • Hard to fit properly in old openings that might be out of square or crowned.
2 – The easiest : INSERT A FRAME AND SASH

The most common system comes as a complete unit that slips into the existing window jambs against the exterior (or interior) window stops. Use low-expanding foam to seal the perimeter gap and ensure an airtight installation.

Important installation details

  • Verify opening for square; measure accordingly.
  • Air-seal the perimeter with low-expanding foam, not fiberglass batts.
  • Fill header and sill extensions with low-expanding foam insulation.
  • Protect against wind-driven rain with highest-quality sealant at exterior stops.

Pros

  • More-dependable energy ratings than Option 1 because the sash and frame are tested as a unit
  • Less invasive than whole-window replacement. The process takes one hour.
  • Won’t disturb existing casings, siding, or wall coverings.

3- The best: COMPLETE REPLACEMENT

When water damage is occurring, the window and rotten framing should be replaced and the source of the leak tracked down and stopped. A rotted window may be the symptom, not the source, of the leak. You can integrate a new window fully into the wall with new head and pan flashings, low-expanding foam, flexible flashing membranes, and high-quality sealants.

Important installation details

  • Protect against wind-driven rain with head flashing and high-quality sealant along top and side flanges; uncaulked bottom flange allows water to escape.
  • Ensure against rot with pan flashing.
  • Integrate flashings shingle style into building paper.
  • Maintain air seal with low-expanding foam along inside perimeter.

Pros

  • Most versatile because you can change the window’s size.
  • The most energy-efficient system because the window is fully integrated into the wall.
  • Most durable because you can upgrade the flashing details.

Cons

  • The most invasive method.