Keyword Site Search

Building a Deck from Stone
Installation System for Elevated Stone Decks, Patios, Balconies and Stairs

By Jasmine Stanley, Power PR for Silca System


A deck or elevated patio built with heavier materials, such as pavers, tile, or flagstone, needs a support system for them. While pedestals are commonly used for rooftop applications, Silca System offers a grate alternative for this system.


When remodeling an existing deck, remove all horizontal flooring and have the framing and footing inspected. If the threshold height needs to be increased, add cleats to the floor joists and inlay the grates on top. Each should be screwed in place with four 3" deck screws.

Decks, elevated patios and balconies are popular choices when designing or remodeling outdoor living spaces. However, if a customer requested a deck made from natural stone, pavers, or tile, the options have been limited due to the weight of the materials and the difficulty of installing them on traditional wood joist framing.

A solution is available in the form of a durable, plastic polymer grid system that facilitates the installation of stone up to 3" thick on elevated surfaces. The system, designed to support the structural load across a 16 inch on center span, opens up a range of stone options for elevated surfaces, including natural stone or concrete pavers, travertine, slate, marble, and tile.

"With traditional deck materials, it was nearly impossible to use stone on an elevated surface," explains general contractor Jim Richardson of Richardson Brothers Construction & Demolition, located in Kendall, New York. "I wanted to offer stone decks to my customers, but any underlayment would have trapped moisture. Plus, the joist system would have to be significantly reinforced to support the weight."

According to Richardson, whose company builds and remodels high-end, custom homes, many of his customers are naturally attracted to stone because it adds substantial value to their homes and increases the aesthetic appeal of the property, while requiring little maintenance.

"In my opinion, no composite deck can compare to the beauty of a stone deck," Richardson adds. "There's something about the stone that adds style and class and just feels solid."

The weather in the upstate New York area can also dictate the use of elevated surfaces for non-deck areas. Due to freezing and thaws in the region, installing stone directly on the ground can have unexpected consequences.


The 16" x 18" grids are made of 1.5" thick, engineered polymer. The honeycombs, which create a super-strong substructure, are each 2" in diameter. The support offered by the system exceeds residential and commercial building codes. The grates can be installed with a drill or impact driver, a circular or reciprocating saw, goggles, measuring tape and a hammer.


When building a new deck or elevated patio, determine the desired elevation and build the substructure to the necessary height using 16 inch on center floor joists. The grates are attached directly to these. The manufacturer recommends staggering the grids for maximum stability; just use a saw to cut them in half.


To finish both remodels and new builds, once the grates are secured, install a geotextile blanket if the paver installation requires polymeric sand. Place a treated lumber border around the edges and install the pavers. The exterior fascia can be covered with vinyl, aluminum, cedar, composite, treated lumber, or any other specified material.

"Even with thorough base preparation, the freezing ground, frequent thaws and ground settling make it very difficult to install stone on the ground," Richardson explains. "As the years pass, pavers tend to heave up and down, requiring further upkeep and maintenance."

Instead, by elevating the stone, "there is no more heaving, and the grass doesn't grow between the pavers," says Richardson.

Richardson adds that the installation of a stone deck with the grid system is comparable in cost to traditional wood or composite decks, depending on the type of stone used.

"When you compare by square footage, the labor and material for installation, the costs for stone decks are very similar to wood or composite decks," says Richardson.

Designed and manufactured by Sare Plastics, a custom injection molding operation, the Silca System is a deck inlay subflooring grid that can be used for both new decks and retrofit applications.

Based on the hexagonal structure of beehives and manufactured from engineered polymers into 1 1/2"-thick grids, the grates ensure a stable, structural surface for natural stone and manufactured pavers. The system is certified to meet building standards by the ICC (International Code Council).

The grates are fastened to the deck joists 16 inches on center using four 3-inch deck screws coated for pressure treated lumber. They can be cut to any length or contour using a circular, table or reciprocating saw.

"I had never seen anything like it before," says Richardson. "I can use it to build anything my customers desire using stone, slate, or bricks - including two-story decks, two or three-tier decks and stairs."

Richardson adds that the system can even accommodate the use of sand, as foundation to even out irregular stone or as polymeric between pavers, by first installing several layers of non-woven textile on the grates.

For more information, call Silca Systems at (330) 821-1585 or visit

As seen in LC/DBM magazine, September 2017.

HTML Comment Box is loading comments...

October 13, 2019, 6:47 pm PDT

Website problems, report a bug.
Copyright © 2019 Landscape Communications Inc.
Privacy Policy