How do you check window sealing skills in Gabiley?

Ask for the wet test record before you accept the work.

Why does a window sealing training certificate not prove skill in Gabiley?

Because sealing is a hand skill, and a written paper cannot show whether a fitter can fold a corner without stretching the material or trapping grit under the tape.

Training that runs in a classroom with a wooden mock-up leaves the hardest parts untested. Wall types vary by plot, and each takes a different fixing and a different seal. Confirm the wall type on your own site and ask the fitter to describe how they will seal it. A fitter who has never worked on that wall type is learning on your building.

Attendance records also hide the common split between the person who was trained and the person who does the work. Ask who will actually install the frames, and ask that person to describe the sequence: how the opening is prepared, where the seal sits in the joint, how the sill drains. General practice is that the seal sits on the warm side of the frame and the joint is left able to drain outward, but confirm the detail against the project specification or the engineer.

Ask the fitter to show a past joint on a finished building and to talk through what was done at that corner.

How does the gap turn into rainwater penetration?

Water gets in through small paths: a joint with no backer, a seal stretched at the corner, a sill that drains the wrong way, a weep hole blocked by mortar.

Wind drives rain against the window and water will find any opening. Ask the project engineer how strong the wet season is on this plot and how much exposure the elevation takes, then set the test and the detailing to that answer. A joint that was filled with a single bead of sealant can hold for one season and then split as the frame and the wall move at different rates. A sill with no outward fall, or one that slopes back toward the room, does not lead water away from the frame and lets it sit at the base of the window. Mortar or paint over a drainage slot stops the wall from emptying itself.

The damage is rarely at the window. Water tracks down the reveal, into the plaster, along a wall plate or into the floor slab, and it appears as a stain metres from the frame. Repairing the stain does not fix the path. Walk a building finished a year ago in the same area, look at the window heads and sills after rain, and ask the owner what was repaired.

How do you test window sealing on site?

Run the same checks on every window, and record them while the work is open.

• Look at the joint before it is closed. Check the backer, the seal position and the corner folds.
• Check the sill slope with a level. Water must run outward, and the drainage path must be clear of mortar and paint.
• Pour water against the frame from the outside, in stages, and watch the inner reveal for damp. Agree the volume and duration with the engineer first.
• Open and close every window after sealing. A frame that binds has been forced out of line.
• Photograph each window before covering and keep the images with the test record.

For local requirements and any inspection the council expects, ask the municipal engineer's office what it holds for the plot and what it requires at completion. Where a specialist subcontractor is used, ask the laboratory or supplier for its method statement and its record of past tests, not just its training list.

What to do next

If it fails, stop the remaining sealing work, retrain the fitter on the joint and the slope, and retest before the next window is closed.