Retrofitting New Windows In An Older House - Part 2

A mark in the center of the window and one in the opening allows Manny to center the window from the outside.

A bead of low-temperature caulk applied around the opening will seal the window flange against the house.

After positioning the window in the opening, Manny checks the top of the window for level.

A level set against the side jamb of the window ensures that it's plumb in the opening.

After confirming that the window is level and centered, Manny nails off the two bottom corners.

Before nailing the top corners, Manny checks the diagonal measurements of the window in both directions to make sure it's perfectly square.

Nailing the top corners locks the unit in position. At that point the rest of the flange can be nailed off.

Before applying the flashing tape to the side jambs, Manny scribes a line about 1/2 inch from the corner of the nailing flange. Starting the tape along this line will help keep it straight as it is applied.

After aligning the edge of the flashing tape with the guideline, Manny carefully presses the tape into the corner of the nailing flange. The free edge of the tape then tucks behind the siding that had been lifted away from the wall slightly when the opening was being prepped.

The window manufacturer specifies that the side flashing tape extend 2 inches past the upper nailing flange of the window. Manny extends the tape past the flange almost 4 inches on both sides.

Flashing tape for the top of the window is wide enough to cover the ends of the side flashing.

Manny installs the first of two pieces of drip cap specified by the manufacturer.

A width of flashing tape secures the drip cap in place.

Before coming to the site to do the installation, Manny cut and preassembled the exterior molding for the window in the comfort of his shop. To join the PVC molding, he glued and screwed the corners.

Manny glues and screws the sill piece to the brickmold trim.

To save time and money, the original siding was kept in place for the installation. To fit the exterior trim, Manny holds the molding in place and scribes a line along the ends of the siding boards.

Manny cuts back to his scribe line using an oscillating cutter to remove the sliver of material.

Raw wood like the cut ends of clapboards is vulnerable to absorbing moisture which can cause paint to fail prematurely, (or worse can lead to rot. A coat of fast-drying primer seals the cut ends before trim goes on).

Manny applies a bead of caulk to the back side of the prefabricated window trim before setting it into place.

Before screwing the window trim into place, Manny adds spacers to hold the trim level.

A concealed fastener system secures the window trim in place. The screws are self-countersinking.

Small plugs made from the same material as the trim are pushed into the holes. When the plugs are hammered flush, the holes completely diappear.

Per the manufacturer’s instructions, a second layer of drip cap is installed over the molding.

Flashing tape seals the drip cap to the wall. The original tar-paper barrier will then flop down to cover the whole assembly.

A tab of tar paper inserts behind the butt joint of the clapboard before the new piece goes in.

A bead of caulk on the butt end of the clapboard provides further protection.

Manny pre-drills lengths of new preprimed clapboards that will be secured with stainless steel nails.

To seal between the window and the trim, Manny first presses foam backer rod into the joint.

A bead of low-temperature caulk is squeezed in over the backer rod. Manny then smooths out the bead with his finger. Note that the joint between the siding and the window trim has also been caulked.

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