First and foremost, it is important to familiarize yourself with the manufacturer's recommendations regarding the installation of pavers on terrace pedestals. Incorrect installation may result in the loss of warranty.
We do not have definitive research or scientific studies confirming the necessity of adding a fifth pedestal in the center, beneath the paver, as an additional measure to prevent cracking. Based on our analysis and experience, the decision to add a pedestal should be evaluated on a case-by-case basis, taking into account the type of paver, the substructure beneath the terrace, and the intended use of the terrace. Recommendations may vary, and it is important to consider several factors before making a decision:
Paver strength and material:
Pavers used on pedestals are made from various materials, such as ceramic, stone, or different types of concrete (pressed, vibrated, reinforced). Each material has different properties, and manufacturers employ various production technologies. We recommend using only high-quality pavers from reputable manufacturers that are designed for point support installation.
Substrate hardness:
Elevated terraces on pedestals can be installed on different types of substrates, including hard substrates like concrete screed or concrete slabs, as well as soft substrates like XPS insulation boards or PIR roof insulation boards. It is important to note that the substrate hardness, recommended to be at least 200 kPa/m² with a preferable level of 300 kPa/m², affects the potential deflection of the terrace during use. An additional pedestal can help distribute the load over a larger surface area.
Terrace load:
When determining the number of pedestals required under the paver terrace, it is necessary to analyze the anticipated load and calculate the total load per square meter of the terrace. Based on these calculations, it can be determined whether the use of an additional pedestal in the center of the paver terrace is recommended. See question 9 - What is the load capacity of the pedestals?
If an additional pedestal is used in the center under the paver terrace, we recommend using pedestals with self-leveling heads to ensure optimal support of the paver using the entire surface area of the pedestal's top cap.
You can find more information in this article- 5 rules to prevent the tiles on adjustable paving slab supports from cracking.
