Installing TGSI’s On Asphalt – What do I need to know?
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A question that we are often asked by first time users and civil contractors is ‘Can I install Tactile Indicators on asphalt?’
The simple answer is no, Tactile Ground Surface Indicators of any type should not be fixed directly to asphalt. This is due to asphalt being an inherently unstable substrate, which is subject to movement caused by:
- environmental or climate influences
- uneven pavement surfaces
- traffic loading
- inadequate mixing
- laying pavement over previous cracks
- drainage deficiencies
- construction deficiencies
However, if treated properly, TGSI’s can be installed safely and correctly to AS/NZS1428.4.1:2009 and the chance of movement and lifting can be eliminated.
Correct / Preferred Method
ESP’s preferred method to properly install TGSI’s on to asphalt is to saw cut out the intended area that will require TGSI’s. Once the asphalt area has been removed, it should be neatly filled in with concrete. This will open up options to the installer, giving them the choice to either install ESP Cast In Place TGSI’s at the time the concrete is poured or retro fit ESP Surface Applied TGSI’s at a later date.
By adhering to this method and following the installation guides, ESP Australia will offer their full comprehensive warranty.
Image Below – The image below demonstrates the preferred method. The neat cuts indicate where the asphalt has been removed and has been replaced with new concrete. This eliminates the chance of ESP’s Access® Tile lifting and will ensure they perform to the highest standard for many years to come.
Installing TGSI’s On Asphalt using Butyl Tape (Application)
Where removing asphalt and replacing with concrete is not an option, an alternative method is to increase the adhesion of the Access® Tile with the use of Butyl tape. The tape replaces our regular method of adhesion (Sikaflex-11FC) and is installed to the underside of the tile around the perimeter. Along with the supplied fixings, this will create the strongest bond possible.
Whilst this method will usually improve the adhesion to asphalt, it will not overcome the longer term instability of the substrate, and therefore ESP Australia is unable to offer a warranty for TGSI’s installed directly on to asphalt.
Calculating Butyl Tape Requirements
Butyl Tape is available in 15m rolls.
In order to calculate how much butyl tape will be required for your project please use the formula below:
Number of Tactile Indicators (300x600mm) X 0.6
Example – 16 x Yellow Warning TGSI (300x600mm) x 0.6 = 9.6 metres
Butyl Tape required = 9.6 metres
If you have any questions regarding installing TGSI’s on asphalt or any upcoming projects that require Tactile Ground Surface Indicators on a different substrate contact us today!
