Most homeowners leave the space under an elevated deck as bare grass or gravel. Reddit user u/stanbo Spent about $7,000 and three months turning it into a handmade flagstone patio. Working almost entirely without heavy machinery, he excavated the area by hand, installed a base of compacted stone and fitted irregular Pennsylvania flagstones to a surface that looked more like natural bedrock than a typical backyard patio.
About $3,200 of the budget went toward three pallets of Pennsylvania flagstone. A borrowed plate compactor handled the base, while an angle grinder, hammer, chisel and patience shaped the finished patio. Reddit users praised the tight joints and natural look, with many calling it one of the best DIY flagstone installations they’ve seen.
The patio started with spray paint and a shovel
The project began by outlining a patio with curved edges beneath an elevated deck. The homeowner removed the existing sod and dug out the entire footprint by hand instead of building on top of the grass.
The sweeping outline extends beyond the deck posts, creating ample space for seating while connecting naturally with the surrounding lawn.
Every inch was dug by hand
After removing the grass, the entire patio area was excavated several inches deep to prepare for the compacted base. Piles of soil surrounded the work area while gorilla carts handled most of the handling.
The homeowner explained that everything was dug, raked, carried and moved by hand, relying on a borrowed plate compactor just after the excavation was complete.
Three pallets of Pennsylvania flagstone came first
The largest material cost came from three pallets of irregular Pennsylvania flagstone stacked on the driveway prior to installation.
Rather than using manufactured pavers, the homeowner chose natural stone because the backyard overlooks the lake and the irregular shape matched the landscape better than straight-edged concrete pavers.
Before any stone went down the base
After excavation, the patio was exposed to layers of compacted aggregate that formed a stable foundation beneath the flagstone.
Gravel covers the entire footprint while grade stacks mark the outside curves. New evergreens and weeping ornamental trees were placed before the stone installation reached them, allowing the planting beds and patio to fit together as one design.
Each flagstone was laid before installation
Instead of setting up one stone at a time, the homeowner spread dozens of flagstones over the prepared base to find the best arrangement. The largest pieces formed the perimeter while the remaining stones filled the center.
Once the overall layout looks balanced, each stone remains in place until the trimming stage creates consistent joints throughout the patio.
The patio began to look like a continuous surface
Irregular flagstones now fit into narrow, consistent joints rather than wide gravel gaps. A dark joint compound filled the spaces between the stones, creating the appearance of a continuous paved surface while maintaining the natural shape of each piece.
The homeowner used NOCO by Techniseal, a hard joint compound chosen instead of loose sand. Reddit users praised the tight spacing, with many calling it one of the best DIY flagstone patios they’ve seen.
The finished surface looked like natural bedrock
Once each stone sat on the level, the irregular shapes formed a continuous surface rather than separate stepping stones.
The patio extended below the full width of the deck while framing the stone without sharp transitions to the surrounding landscape.
Fresh landscaping softened the stone
Curved planting beds wrap around the patio using mulch, shrubs, ornamental grasses and small weeping trees.
Instead of straight edges, the beds followed the same flowing lines established by the flagstone, making the patio look integrated into the backyard rather than added later.
Each deck post was worked into the layout
Stone masonry is tightly wrapped around each structural post supporting the upper deck.
Instead of cutting the patio into separate sections, the flagstone continued under the entire structure, creating an uninterrupted outdoor living area with space for grilling, seating and movement.
String lights finished the outdoor room
After the stonework was completed, the homeowner painted the deck dark, added cafe string lights under the joists, and outfitted the patio with wood-framed seating and hanging chairs.
The previously empty space below the deck became the primary outdoor gathering area while the upper deck remained available for dining.
Each step before and after this shows paid
The original backyard had nothing but grass under the raised deck.
Three months later, the space became a flagstone patio surrounded by landscaping, lighting and outdoor furniture. Reddit users praised the precise stone fittings, consistent joints and natural look, with many commenting that it looks better than professional installations they’ve seen.
All image credits go to the Reddit user u/stanbo.
