Window & Door Perimeter Failure

Inspection Requirements

• Inspect all window and door perimeters on the exterior facade for sealant cracking, adhesive failure, gaps and missing sections.
• Check all timber window and door frames for softening, rot, section loss and paint failure — probe suspect areas with a sharp tool to detect concealed decay.
• Attempt to open and close all operable windows and doors to identify sashes that are jammed, binding, swollen or no longer functioning correctly.
• Inspect window and door head flashings for correct installation, slope, continuity and condition — absent or failed head flashings are a primary cause of ingress.
• Check for the presence and condition of storm angles (return leg at the jamb) — absent or missing storm angles allow wind-driven rain into the frame-to-facade junction.
• Inspect sill flashings and drip edges for correct slope and drainage — flat or reverse-sloped sills direct water toward the frame rather than away from it.
• Inspect subsill detailing for correct waterproofing, slope and drainage — particularly at aluminium-framed windows where the subsill must drain outward.
• Assess the internal reveals at windows and doors for staining, paint failure, plaster damage and mould — these indicate ongoing moisture ingress.
• Check the weepholes in window frames for blockage — blocked weepholes allow water retained in the frame to overflow internally.
• Inspect the interface between the window or door frame and the surrounding render, brickwork or cladding for gaps, cracking and open joints.
• For balcony doors: inspect the door hob (threshold) for correct height and waterproofing angle detail — a non-compliant or absent door hob allows water driven across a wet balcony to enter the interior.
• Conduct a hose test on suspect perimeters — apply water at window head and track ingress points internally.
• Review window and door installation documentation for compliance with manufacturer requirements, particularly for minimum sill slope, flashing specification and sealant type.

Typical Repair Methodology

Window and door perimeter repairs must address all contributing defects as a combined system — flashings, storm angles, sill drainage, sealant and frame condition. Rectifying only one element while leaving others defective will result in ongoing water ingress.

1. 01.Identify all water entry points through hose testing and internal inspection before commencing works.
2. 02.For timber windows and doors with localised rot: remove all rotted timber using chisel and oscillating tool, treat surrounding timber with an appropriate timber hardener, and fill with a two-part epoxy wood filler shaped to profile before repainting.
3. 03.For timber windows and doors with extensive frame decay or structural failure of the frame: replace the full window or door unit. Engage a joiner or window specialist to fabricate a replacement to match the original profile where heritage requirements apply.
4. 04.For jammed or binding timber sashes: assess the cause — if swelling from moisture ingress, resolve the ingress first, then plane or sand the sash to correct clearance. Repaint all bare timber after adjustment.
5. 05.Remove all existing perimeter sealant from the window or door frame-to-facade interface using a sharp knife and oscillating tool.
6. 06.Clean all joint faces thoroughly to remove all dust, contamination, old sealant residue and bond breakers.
7. 07.Install backer rod at the correct depth to achieve a 2:1 width-to-depth sealant joint ratio.
8. 08.Prime joint faces with the sealant manufacturer's specified primer for the substrate combination.
9. 09.Apply a neutral-cure silicone or polyurethane sealant to the perimeter joint, tooling to a concave profile for positive drainage.
10. 10.Where storm angles are absent or failed: install a new powder-coated aluminium or stainless steel storm angle to the jamb, bedded in sealant, with the return leg lapping the facade substrate by a minimum of 50 mm.
11. 11.Inspect and rectify window head flashings — where absent, install a correctly sloped stainless steel or colorbond flashing with a minimum 10 mm overhang and stop ends to the sides.
12. 12.Where subsill drainage is inadequate or absent: cut a channel and install a correctly sloped subsill tray with a weephole to the external face before resealing.
13. 13.Clear all blocked weepholes in window frames and ensure the drainage system within the frame is functional.
14. 14.Where sill slope is inadequate, apply a mortar fillet or packing to achieve a minimum 1:40 slope away from the frame before resealing.
15. 15.For balcony doors with a non-compliant or absent hob: construct a correctly detailed hob to the manufacturer's and NCC minimum height requirement, incorporating a waterproofing angle at the base of the door frame before screed and tiling are reinstated.
16. 16.Repair all internal plaster, render and paint damage resulting from the water ingress after confirming the ingress source has been resolved.
17. 17.Conduct a follow-up hose test after all works are complete to confirm the repair is effective.
18. 18.Record all repairs with photographs and product details for the strata maintenance register.