Window Seal and Gasket Replacement in Dunedin – Perished Rubbers, Wedges & Weather Seals

In a city that records around 50 ground frost days a year, a window with perished seals is a hole in the wall. Cold air moves through the gap all night and the room never holds its heat. Re rubbering is the cheapest item on this website and it changes how a room feels more than anything else at the price.

What really perishes

Two different rubbers do two different jobs. The glazing wedge sits between the glass and the frame and keeps water out of the rebate. The weather seal runs around the sash and gets compressed every time you close the window.

The weather seal fails first because it is worked constantly. Once it has flattened it no longer compresses, so there is a permanent air path around the sash even with the handle locked down.

How to tell it is the rubber

Press the seal with a fingernail. Live rubber springs back. Perished rubber stays indented, feels chalky and often has cracks along the corners. If you can see daylight at the corner of a closed sash, or a piece of paper pulls out easily with the window locked, the seal is gone.

What it fixes and what it does not

Re rubbering stops the whistle, cuts the draught, and in most cases stops water being driven past the sash. It will not fix water coming from a failed head flashing above the window, and it will not fix a window whose drainage slots are blocked.

So we test and not assume. If the leak is not the seal we tell you that instead of selling you rubber that will not solve it.

Knowing which seal has failed

The paper test

Close the window on a strip of paper and pull. If it slides out with no resistance the weather seal is no longer compressing anywhere near that point. Repeat it at the corners and along the middle, because seals flatten unevenly.

That takes thirty seconds and tells you more than looking at the rubber, which can appear fine while having lost all its spring.

Wedge or weather seal

The glazing wedge sits between glass and frame and its failure shows as water in the rebate or a rattling pane. The weather seal runs around the sash and its failure shows as a draught and a whistle.

They are different profiles, different prices and different jobs, so we identify which one before quoting rather than replacing both by default.

The window seal and gasket replacement process Window and Glass Repair Dunedin uses in Dunedin

Sealing work is simple to describe and frequently done in a way that does not last, because whatever caused the seal to fail was never addressed.

1. Find where air and water are actually moving

   Window and Glass Repair Dunedin checks the perimeter seal, the meeting rail, the glazing tape and the gap behind the architrave. A draught felt across a room usually comes from one hardened corner you cannot see from either side.

2. Rule out drainage first

   Aluminium frames admit water by design and drain it back out through weep holes. Blocked weeps present exactly like a failed gasket and clearing them costs almost nothing, so it gets checked before any reseal is quoted.

3. Separate draught from cold radiation

   A single glazed window on a Dunedin frost morning feels draughty even when it is perfectly sealed, because you are losing heat to a cold surface rather than to moving air. Window and Glass Repair Dunedin says which one you have, since sealing does nothing for the second.

4. Match the gasket profile exactly

   Profiles vary between joinery systems and a near enough gasket leaves gaps at the corners, which is precisely where most resealed windows still leak. Window and Glass Repair Dunedin matches rather than using whatever is in the van.

5. Strip and clean the rebate properly

   Beads off, old tape and gasket removed, rebate cleaned back to sound material. New sealant laid over old residue does not bond and fails within a couple of seasons.

6. Fit new seals with the corners closed

   New glazing tape and gasket fitted, corners closed rather than butted, beads refitted instead of forced. Compression is checked along the whole seal path with the sash closed.

7. Confirm the fix rather than assume it

   On a leak the opening is water tested again. On a draught the seal is checked for even compression end to end. Leaving without testing is how one window gets two visits.

Why sealing work pays off in Dunedin

In this climate the seals around a window are doing more work than almost anywhere else in New Zealand.

Fifty frost days a year is a hard test

Repeated freeze and thaw cycles harden rubber faster than UV alone. Gaskets that would last twenty years in a mild climate are perished and pulled back from the corners well before that here.

Heating costs make it worth doing

Dunedin sits in the highest insulation requirement zone in the country precisely because heat loss is greater here. Sealing an existing window is the cheapest intervention available and it is usually the first thing worth doing.

Sealing and ventilating are not opposites

A tighter house holds moisture that used to leak out through the gaps. Window and Glass Repair Dunedin raises extraction and ventilation alongside sealing rather than instead of it, because sealing a damp house without ventilating it makes condensation worse.

Healthy Homes still requires openable area

Sealing must not stop a window opening or being fixed open. On a rental that is a compliance matter, not a preference, and a painted shut sash fails the standard even though it exists.

What window seal and gasket replacement costs in Dunedin

This is the cheapest meaningful improvement available on an existing window, and the payback in a climate zone 5 city is faster than anything else in this trade.

Per window reseal

Beads off, old tape and gasket out, rebate cleaned and drainage cleared, new tape and gasket fitted, beads back. It is a couple of hours per window and it restores the window to how it performed when it was new.

Draught proofing a sash

Brush seals in the stiles and at the meeting rail on a double hung sash, with no visible change from outside. On a Dunedin villa the meeting rail is the single largest draught path in the house, so this is the highest value line on the quote.

Whole house

Doing every window in one visit brings the per unit cost down substantially, because the visit rather than the materials is most of the price. It also means the house performs as a whole rather than one room at a time.

What it saves

Dunedin sits in the highest insulation requirement zone in the country precisely because heat loss here is greater. Sealing does not change the glass, and it removes the air movement that makes a room feel colder than the thermometer says.

Sealing, draught proofing or glazing: what to do first in Dunedin

In order of cost, and in the order that actually returns the most.

Clear the drainage, first and cheapest

Blocked weep holes present exactly like a failed seal and cost almost nothing to clear. This gets checked before anything is quoted, because a reseal on a window with blocked drainage solves nothing.

Reseal and draught proof, second

Perished gaskets and an open meeting rail are the two largest air paths on most older Dunedin windows. Fixing them is inexpensive, quick and it makes the most noticeable difference to how a room feels.

Retrofit the glass, third

Once air movement is dealt with, the remaining loss is through the glass. Retrofit double glazing at roughly $450 to $800 per square metre is the next step and it is where the larger spend belongs.

Replace the joinery, last

Only where the frames are failing or the work is consented and has to meet climate zone 5. Doing it first, before sealing and ventilating, is spending the most money on the least urgent problem.

How window seals fail in Dunedin

Seals are consumables. They have a life and it is shorter on the weather side of the house.

UV hardens the rubber

Wedge gaskets and weather seals go hard, shrink and pull back from the corners. Once they no longer compress, the window whistles in wind and lets water past.

Compression set from being shut

A seal held compressed for years stops springing back. The window appears to close normally and no longer seals, which is why draughts appear without any visible damage.

Glazing tape failure behind the bead

The tape between the glass and the frame is what stops water reaching the rebate. When it fails, water sits in the frame and the first symptom is usually a stained sill inside.

Reseal or replace on a Dunedin window

Resealing is one of the highest value repairs available because the frame and glass stay put.

What a reseal involves

Beads off, old tape and gaskets removed, rebate cleaned and drainage cleared, new tape and new gasket fitted, beads back. It is a couple of hours per window and it restores the window to how it performed new.

Matching the gasket profile

Gasket profiles vary between joinery systems. Fitting a near enough profile leaves gaps at the corners, which is where most resealed windows still leak.

When a reseal is not enough

If the frame corners have opened or the section is distorted, no gasket will seal it. We check the frame before quoting a reseal rather than after.

Window Seal and Gasket Replacement at a glance

Glazing wedge

Replaced in place, glass usually stays in the frame

Weather seal

Q lon, bubble and fin seals to suit the suite

Symptoms fixed

Whistling, draughts, rattling sashes, driven rain past the sash

Not fixed by this

Head flashing failures and blocked drainage slots

Typical time

Around fifteen to thirty minutes a window