Window Sill Replacement

Select sealants that:

are compatible with their intended surfaces,

allow for differential expansion and contraction between dissimilar materials,

meet the requirements of the applicable fire safety code (e.g. thermal or ignition barriers), and

for use inside the pressure boundary select low volatile organic compound (VOC) sealants that meet independent testing and verification protocols

Select:

pest-resistant materials that adequately support applied load and are permanent air barriers,

materials that meet the requirements of the applicable fire safety code (e.g. thermal or ignition barriers), and

low volatile organic compound (VOC) materials for use inside the pressure boundary that meet independent testing and verification protocols

Remove any material from the sealing area that will prevent full adhesion of the selected sealant

Remove any material from the sash contact areas that will prevent a tight seal or safe operation

Install beveled sill flush with interior wall and sloped to the exterior of home at a minimum of 14 degrees

Apply continuous and complete seal at all connections/joints of the sill to the jambs, frame, and exterior wall

Water-seal and prime new sill if water permeable

Wrap old sill/ and any removed materials in plastic and dispose of them off-site in a manner that is compliant with local, state, and federal regulation

Verify safe operation and size of egress windows as required by local codes