Part 2: Quick guide to measuring glass partitioning

Last month, in Part 1 of the Guide to Measuring Glass Partitioning, we looked at the first step: Measuring openings and site survey. We looked at taking measurements from various points in an opening and going through all the necessary checks on-site in preparation for the glazing channel track installation. We also looked at critical steps to making a full site survey.

Once the glazing track is in position, the partitioning glass is ready to be measured for production and then installed. For Part 2 of this guide, we will look at the second step: Measuring glass for production and installation.

Above: Basic example of a glass partitioning drawing

Before measuring

Before measuring it is good to practise to check the track has been correctly installed. Here are just some of the checks we recommend:

1. Check the track has been securely fixed

2. Ensure all straight joints and mitre joints have no visible gaps

3. Check that there are no visible gaps between the track and the surface to which the track is fixed (especially on the wall abutments)

4. Check for damage on the track (scratches, permanent marks and dents)

5. If there are T-junctions, ensure the track has been correctly cut. And the tracks go into each other, rather than across each other. In the diagram below, the first image shows the glazing track incorrectly installed at a T-Junction. The second image shows the track correctly installed with the tracks going into each other (this way the glass edges will meet).

Above: T-Junction glazing track (correctly and incorrectly installed)

In all the above cases, the issues are best resolved before the glass is installed. While waiting for the glass to be produced and delivered, it is recommended that the track is covered and protected with Correx sheets or similar protective material to ensure the track does not get damaged.

Measuring Glass

Heights

Nowadays, bottom track usually consists of 2 Part Track; one part is fixed into the ground surface (usually “L-Shaped”) and a second part that is used as a “clip-on” bead - clipped in once the glass panel is in place. With this method, the glass panel will be tucked into the top track and rest on the bottom track. Once the glass panel is in place, the bead is clipped in on the bottom track. Full height measurements need to take into account the depth of the pockets in the top and bottom track. It is a good idea to contact the track manufacturer to obtain details and measurements of the profile, especially the pocket area for accuracy. Also, check the glazing track inserts or gaskets and glass packers that may need to be inserted in the bottom track. These items and others should be deducted off your full height measurements, giving you the glass panel heights.

Above: A basic example of a 1 part and a 2 part glazing floor track

If a solid bottom track (or one part track) and solid top track are being used, the glass will need to be installed using an “up and over” technique. This is done by lifting the panel fully into the top track pocket to go over the bottom track and then lowered into the bottom track pocket. For this method, the full height should be measured and then the hight of the bottom track deducted. You may want to deduct further due to glass factory tolerances. This will mean the glass can be lifted over the bottom track, while fully tucked into the top track. Glass packers can be placed inside the bottom track pocket to ensure glass panels have sufficient hight to stay inside the top track once lowered into position. Usually, glass packers come in 1-6 mm thickness - it is vital to ensure the glass panels sizes will allow for it to sit securely inside the pockets before ordering the glass.

Remember to:

1. Measure the height on several points to pick up any variances especially on longer the runs

2. Check the level of all surfaces

Widths

As with the glass panel heights, check the pockets depths of the wall abutments (and door legs) into which the glass will “slide”. As mentioned above, it is a good idea to contact the glazing track manufacturer and obtain details of the profile, especially the U-Channel pockets. The types of glazing joints specified are another critical consideration. In glass partitioning wet joints or silicone joints usually vary between 3-6mm in width. While partitioning dry joints (pre-formed plastic joints with adhesive tape) typically require a 2-3mm gap, sometimes special double-sided glass partitioning tape may be specified.

Remember to:

1. Measure the widths on several points to pick up any variances

2. Check the level of all surfaces (including door legs) to ensure these are vertical

Once the width has been obtained, glazing inserts, pocket depths restrictions inside the glazing channel, etc. should be deducted. Once the deductions have been made, the width is normally be divided into equal parts. Glass panels are usually 700mm to 1,000mm wide. Doors (depending on access, their use and building requirements) are usually 900mm wide. Glass panels next to doors or on T-junctions tend to be narrower, and often referred to as glass rips. Check the number of joints on the opening width and deduct these measurements too.

Submitting Measurements for Production

We recommend having a detailed drawing of the area to be glazed. Each panel should be numbered on the drawing. When submitting measurements, each panel should be listed and numbered with their respective sizes (width x height) and specifications.

Additionally, a list submitted for production should also include:

• Glass thickness - for example, 10mm, 12mm, etc.

• Details of glass panels that require cut-outs - a notch in the glass usually to accommodate skirting, piping, etc. Preferably include a diagram of the glass panel with measurements of the cut-out

• Details of raked glass panels - where a glass panel will be installed next to a slope, for example, a 30 degree angled ceiling. Preferably include a diagram of the panel

• Glass mitre joints - 2 glass panels meet at an angle, and the edges need to be angled. For example, two glass panels forming a 90-degree corner may need to have a 45-degree edge. This will form a 90-degree corner

• Glass type specifications - such as laminate, acoustic, etc

• Specify if you want only certain edges or sides of the glass polished or if you would like these to be polished all-round (often abbreviated as PAL)

Depending on the project, other specifications may be needed. For example, hinge cut-outs details for glass doors, glass edge details, etc. See the first image.

Summary

Part 1 and 2 of this guide we have had a brief look at the step by step process to measuring for glass partitioning, this was done in 2 parts:

1. Measuring openings and site survey

2. Measuring glass for production and install
   

There are many considerations to take into account, but these are all vital to reduce costly errors. It is impossible to cover all aspects and factors, such as measuring a curved glass screen, glass door details, glass T-junctions, double glazed partitioning and more.

Each job will be unique and have its own complexities. It is impossible to cover all aspects of measuring and site surveys. That's why we recommend using qualified experienced partitioning fitters to both measure and install your partitioning project. This article only covers just some on the steps we take to measure glass and track for a glass partitioning fit-out. At Prism Glass, we have over ten years of experience in the industry and have worked on many glass installation projects. If you need assistance with your project, please contact us, and we will be more than happy to help.

About the writer: Paulo Ferreira has extensive experience in project management and worked at Prism Glass for two years, where he managed glass installation projects and day to day operations. He also has extensive experience in financial services. His skills include graphic design, branding, content marketing and blogging.

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