Phase 1: Pre-installation planning

Resolve scope questions before the crew loads the truck. The installer should receive the approved order, field-measure sheet, photographs and finish selections—not a verbal summary.

• Confirm project address, opening designation and installation date.
• Review door collection, size, glass, finish, swing and handing.
• Verify sidelights, transom, frame, sill, brickmould and hardware.
• Review known rot, framing, siding, masonry, flooring and trim work.
• Identify lead-safe, permit, code or access requirements.
• Check weather forecast and safe site conditions.
• Confirm tools, fasteners, flashing, sill pan, sealants and insulation.
• Define protection, debris removal and homeowner access.

Phase 2: Delivery inspection—before removing the old door

The existing entry should remain functional until the replacement unit has passed inspection. A damaged, mirrored or wrong-size door discovered after demolition turns a controlled installation into an emergency enclosure.

Phase 3: Protect the home and remove the existing unit

• Protect flooring, walls, furnishings, steps and landscaping.
• Disconnect alarm contacts, smart devices and doorbell wiring safely.
• Score painted joints before removing casing or exterior trim.
• Remove the old unit without unnecessarily damaging the water-resistive barrier or cladding.
• Control sharp materials, glass and debris.
• Separate salvageable hardware or trim only when the scope requires reuse.
• Keep the opening protected if work pauses.

On older homes, stop when demolition exposes unexpected lead-painted surfaces, structural alteration, active water intrusion or extensive rot outside the approved scope.

Phase 4: Inspect and prepare the rough opening

Therma-Tru’s prehung installation guidance calls for verifying opening size, plumb, level, square, plane and a solid bearing surface beneath the sill. Correct problems now; shims cannot turn damaged framing into sound structure.

1. Measure rough-opening width at top, middle and bottom.
2. Measure height from structural support to the header.
3. Check both jamb sides for plumb in both directions.
4. Check the header and sill support for level.
5. Compare diagonal measurements for square.
6. Use a string test or equivalent check for wall-plane twist.
7. Probe stains and soft material; identify active moisture sources.
8. Repair framing, subfloor and sheathing before setting the unit.
9. Vacuum and clean the opening for reliable sealant and flashing adhesion.

Refer to the exterior door rough-opening field guide when the existing framing differs from the approved dimensions.

Phase 5: Build the water-management layers

Flashing should direct water down and out through overlapping layers. Therma-Tru recommends a water-resistive barrier, flexible flashing and a sill-pan system in its published installation method.

• Repair or integrate the water-resistive barrier around the opening.
• Install flashing from the bottom upward in shingle fashion.
• Dry-fit, assemble and seal the sill pan according to its instructions.
• Preserve the intended exterior drainage path.
• Use compatible elastomeric or polyurethane sealant where specified.
• Do not place sealant where it blocks sill-pan drainage.
• Plan head flashing beneath the upper water-control layer.

When repairing a previously wet opening, correct the source and dry or replace damaged materials before enclosing them.

Phase 6: Set and temporarily secure the unit

1. Keep the unit secured with its shipping device until the instructions direct removal.
2. Apply the specified sill and perimeter sealant.
3. Set the sill first, center the frame and tilt the unit into the opening safely.
4. Confirm equal trim coverage and frame position from inside and outside.
5. Temporarily fasten through the locations required by the system—not through brickmould unless expressly directed.
6. Recheck the unit before permanent adjustment begins.

Wide units with sidelights, transoms or double doors require adequate labor and support. Protect glass and finished surfaces throughout handling.

Phase 7: Plumb, shim, fasten and align

Start with the hinge-side jamb. Shim at required hinge and anchor locations, keeping the jamb straight and plumb in both directions. Therma-Tru’s instructions call for long hinge screws into framing to help anchor the unit and prevent sag.

1. Plumb the hinge jamb without twisting it.
2. Shim behind hinge and fastener locations.
3. Drive fasteners incrementally and recheck after each adjustment.
4. Align the head and lock-side jamb for consistent reveals.
5. Confirm even weatherstrip contact at top, middle and bottom.
6. Shim behind the strike for solid hardware support.
7. Anchor mull posts and complex configurations as directed.
8. Recheck plumb, level, square and plane before final tightening.

Phase 8: Adjust operation, sill and seals

Remove the shipping device at the specified step and cycle the slab repeatedly. The door should swing smoothly, latch without slamming and show consistent margins.

• Align latch and deadbolt with their strikes.
• Adjust the strike for secure latching and proper seal pressure.
• Tune the adjustable sill using the current instructions.
• Use the recommended dollar-bill test across sill adjustment points.
• Install or verify corner seal pads on applicable inswing systems.
• Confirm sweep contact without excessive dragging.
• Check double-door astragal, active panel and slide-bolt operation.

Phase 9: Insulate and weatherproof the perimeter

Fill the cavity around the frame with an insulation method compatible with the door and opening. Do not overfill or bow the jambs. Then complete exterior flashing, head protection and sealant transitions while preserving drainage.

• Inspect the perimeter gap before insulation.
• Maintain jamb position while insulating.
• Integrate head flashing with the upper water-resistive layer.
• Seal specified brickmould, jamb and molding joints.
• Seal exterior hardware penetrations where directed.
• Keep intentional drainage paths open.
• Test again before installing trim.

Phase 10: Complete trim and finish

Interior casing, brickmould, caulk and touch-up work should make the entry look designed for the home. Confirm that trim covers demolition lines without crowding lights, switches, siding details or masonry.

• Use clean, balanced casing reveals.
• Keep visible sealant joints narrow and properly tooled.
• Fill approved fastener locations neatly.
• Follow current finishing deadlines and product-specific instructions.
• Keep paint, stain and topcoat off weatherstripping.
• Complete all required slab edges, frame and trim surfaces.
• Clean glass, sill and hardware without damaging finishes.

Final quality-control checklist

Homeowner handoff

The handoff is part of installation quality. Demonstrate the door instead of leaving manuals on a counter.

1. Show normal opening, closing, latching and locking.
2. Demonstrate multipoint locks, adjustable features or between-glass controls.
3. Explain that the door should not require slamming or lifting.
4. Review cleaning, finish inspection, sealant and weatherstrip maintenance.
5. Explain finishing deadlines when field finishing remains incomplete.
6. Provide warranty, product and care documents.
7. Record accepted punch-list items and completion dates.
8. Obtain customer acknowledgment after the walkthrough.

Closeout documentation

• Approved order and configuration drawing.
• Product labels, serial or manufacturing information.
• Before, opening, flashing, fastening and final photographs.
• Moisture or structural repairs completed.
• Sealant, flashing, insulation and finish products used.
• Final operation and quality-control checklist.
• Warranty registration or documentation as applicable.
• Homeowner handoff and punch-list record.

Common installation-process failures

• Demolishing before verifying the new unit. Wrong size or handing becomes an emergency.
• Shimming around rotten or unlevel framing. The frame cannot remain stable.
• Fastening until the frame looks straight but ignoring plane. A twisted jamb leaks and binds.
• Installing trim before operation testing. Correctable conditions become concealed rework.
• Overfilling insulation. The jamb bows and reveals change.
• Treating handoff as paperwork. Misunderstood operation creates avoidable callbacks.

The bottom line

A repeatable entry door installation process protects performance, appearance and contractor margin. Verify the unit before demolition, keep water moving outward, align the frame before closing walls and document the finished system.

The ruthless rule is simple: never conceal a condition that has not passed inspection. Trim is the reward for a correct installation, not a cover for unfinished work.

Frequently asked questions