Secondary Glazing Help Guide

1. Measuring Your Windows

When measuring your windows for secondary glazing you need to make sure that the plastic will overlap the frame by at least the thickness of the magnetic tape.

If you can leave a bit more room either side, even better. It will make removing the secondary glazing that much easier.

We have two types of magnetic tape, each with slightly different widths:

Standard Tape: 13mm wide

Extreme Tape: 25mm wide

Standard Fitting Diagram


Close Up


Edge to Edge Fitting Diagram


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2. Choose the Correct Kit

"I have measured up, now what?"

We offer a range of magnetic glazing kits. These are made up of either Standard or Extreme Magnetic tape, and an acrylic panel of various thickness options.

Which option you go for, is determined by the perimeter of the panel.

"How do I work out the perimeter?"

The perimeter is calculated by adding the length and width, then multiplying by 2.

For example, the calculation for the perimeter of a panel 2000mm x 1000mm is as follows:

2000 + 1000 = 3000

3000 x 2 = 6000

Perimeter is 6000mm (6 metres).

"Now I have the perimeter, how do I know which Secondary glazing kit I need?"

Panels under 4000mm perimeter
– Can be 2mm standard kit (15mm wide tape).

Panels under 4500mm perimeter – Choose the 3mm standard kit (15mm wide tape).

Panels over 4500mm perimeter – Choose the 4mm extreme kit (25mm wide tape).

Panels over 5000mm perimeter – Choose 4mm extreme kit (may require additional fixings such as screws to help support the weight of the panel).


3. Calculate How Much Tape You Need

"What is Magnetic Tape?"

Magnetic Tape is supplied on a roll, and is used to hold the panels on the window frame.

These rolls are made up of two parts; the steel strip, which sticks to the window frame and a magnetic strip which sticks to the acrylic secondary glazing panel.

Both of these tapes are white on the reverse side, to blend in with most window frames.

Once fitted, the secondary glazing system creates a sealed system to combat draughts, condensation and minimises road noise.

The secondary glazing system is also easily removed when not required, or for cleaning.

The thickness of both parts of the tape combined is approximately 3mm thick once fitted.

"How Much Tape Comes on a Roll?"

Our Standard Magnetic Tape tape is 15mm wide and is 5 metres in length per roll.

Our Extreme Magnetic Tape is 25mm wide and is 10 metres in length per roll.

"How Many Rolls Will I Need?"

To work out how many rolls of tape is required you need to take the perimeter of the total number of panels you are ordering and see how many rolls that fits into. 

Make sure you take note of which system you'll be ordering, standard or extreme, as these come in different lengths (shown above).

For example, if you were ordering 3 panels of 2000mm x 1000mm, you would calculate:

Perimeter of this panel would be 6000mm (6 metres).

Then, times this by 3 (number of panels) to get the total perimeter for all of the panels.

This would be 18,000mm (18 metres).

Therefore, this order would require 2 rolls of Extreme Glazing tape.

"How Do I Order?"

To order your magnetic secondary glazing kit, navigate to the correct page (linked below) and enter the measurements you have calculated to get your instant quotation and order online.

Click here for the Standard Secondary Glazing Kit

Click here for the Extreme Secondary Glazing Kit

Click here to view all Secondary Glazing products

4.  Install The DIY Secondary Glazing Kit

1.  Clean and degrease the window frame using a suitable cleaner.

2.  Lay the panel flat. Measure and cut each length from the roll of Magnetic Glazing tape. You will need a matching steel strip and magnetic strip for each length.

3.  Stick the magnetic strip (thicker, more flexible side) to the edges of the acrylic panel. If you have left enough room for fingertip clearance, remember not to position the tape directly on the edge, instead leave the small gap. If you have not, then proceed with the tape meeting the edge.

4.  Hold the acrylic panel to the window frame so that it overlaps equally on each side.

5.  Draw a pencil line around the sheet on the frame.

6.  Cut and fit the white metal strip to the window frame to match the position of the magnetic tape on the acrylic panel.

7.  Offer up the glazing panel to the window and click into place.

8.  Note that it is possible to paint over the steel strip in order to match your window frame. This will not reduce the magnetic grip but will improve the look of the window when the panel is removed.

CAUTION - Care must be taken when handling the steel strip as the edges and trimmed corners can be sharp. This can cause paper cut injuries if not handled with care.

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Secondary Glazing Help Guide