BUILD · HARDSCAPE
Hardscape.
Lueders limestone, Pennsylvania bluestone, decomposed granite, pea gravel — the materials the DFW region was already making of itself before any build began. We specify, source, and set them within the architectural lines the site already implies.
PALETTE
Four materials, mostly.
Lueders limestone
Lueders limestone is quarried in Lueders, Texas, roughly two hours west of Dallas — the same dolomitic limestone the region's public-works hardscape has been set in for a century. The color range runs warm cream through gold into a deeper honey at certain seams; it weathers rather than deteriorates, taking on a soft patina without structural loss. We spec it in three finishes — full-brushed (honed smooth for interior register and dining terraces), sawn (clean-cut edges for contemporary lines and pool coping), and chopped (rougher face for walls, steps, and naturalistic edges). It is our default stone for terraces, seat-height retaining walls, steps, and pool coping. The density profile — low porosity, tight grain — is what carried it through Uri where softer sedimentaries spalled.
Pennsylvania bluestone
Pennsylvania bluestone reads cooler — a blue-grey to charcoal that pulls against cream stone rather than blending with it — and it is where we go when the architecture or the register calls for a more contemporary, modernist, or northern-European tonality. Thermal-finished bluestone is our default cut for terraces and stepping stones; its surface is flat enough to read cleanly and textured enough to stay non-slip when wet. It behaves slightly differently from Lueders in freeze: the joint treatment has to be more generous, and the bedding depth tighter. We use it in full-terrace applications where the architecture wants the cooler register, or as stepping stones in a warm-stone field where a single line of bluestone runs a transitional axis.
Decomposed granite
Decomposed granite is the walking surface that asks the least of a site — a fine crushed stone that compacts into a stable, permeable path without a poured base. Our default runs stabilized DG with a clay binder on primary axes that see dining-adjacent traffic, and loose DG on secondary paths where the maintenance register is lower. We size the path to the architectural line — a 42-inch DG path reads as generous where a 36-inch default would cramp — and detail the edge with a steel or stone header so it stays defined rather than drifting into the adjacent bed.
Pea gravel
Pea gravel is a category we use narrowly. It works as a casual path surface where the register is loose — gravel garden, courtyard, kitchen-garden axis — and as drainage fill behind retaining walls or around permeable downspout fields. It does not work as a dining surface (chair legs catch and scrape) and it does not work on a formal axis (it reads as unresolved against stone or steel). Where we do use it, the edge detail is non-negotiable: a steel header, a stone band, or a hard line cut into an adjacent surface, or the gravel migrates in three seasons.
Material decisions are made on the drawing set authored in the landscape design phase, not negotiated on the job site.
TECHNIQUE
Drylaid where the site allows. Mortared where it doesn't.
The base is the work. Four to six inches of washed crushed stone — our preferred grade is a three-quarter-inch minus with fines — compacted in lifts, topped with a thin bedding layer of concrete sand leveled to final grade. Stone is set tight, joints at a quarter-inch or less, and the field is swept with the same bedding material or with polymeric sand on higher-traffic applications. The result is a surface that reads crisp at year one and broken-in at year five, where a re-sweep or the occasional stone pull-and-reset is the only maintenance register. Drylaid is our default for paths, secondary terraces, and pool-deck transitions where the site drainage can receive water through the joints rather than routing around the hardscape.
On primary terraces adjacent to the house, on pool coping, on wet-side runs where water must sheet to a defined drain, we set in mortar over a reinforced concrete sub-slab. Post-Uri the mortar chemistry shifted: we now spec a lime-rich Type N formulation with a freeze-thaw admixture package, called out on the terrace detail rather than assumed. Expansion joints are drawn at built-line dimension — typically every 16 to 20 feet depending on orientation — and honored during construction rather than negotiated at the pour. Strike pattern is documented as slightly concave at the face to shed water. The quality-control check is that every joint reads the same width and the same recess across the field; variation in strike is where water finds its way in.
RESILIENCE · HARDSCAPE AFTER URI
What the 2021 freeze taught us about mortar and stone.
The pre-2021 DFW trade default ran cement-heavy and lime-poor, which produces a stiff mortar that cracks rather than flexes when the substrate moves under freeze. We saw that failure mode on terraces all over the metro that winter — hairline cracks walking the grout line, then opening into spall on the first thaw, then taking water on the next freeze. The revised Alterra spec is a lime-rich Type N formulation with a freeze-thaw admixture package that we name on the drawing. Substrate prep matters as much as mix: clean, damp, at ambient temperature above forty degrees during set. None of that is exotic. It is the quiet craft discipline the trade had drifted away from, which we re-spec'd deliberately.
Lueders limestone came through Uri with almost no field-reported failures at scale, which matches its geological profile: dolomitic, low-porosity, tight-grained. Some imported sandstones failed visibly — face-shell delamination, spall at the freeze-thaw interface, pieces that had to be pulled and replaced on otherwise-healthy terraces. Travertine in coping use behaved worst. The lesson was specific rather than general: what the stone does in your hand and on the sample board is not what it will do on a terrace that has sat at 18 degrees for five days and then taken a driving rain at thirty-five. We set Lueders as the default, specify bluestone where the register calls for it, and send imported sandstone to dry-laid path work where a pull-and-replace is cheap.
The joint is where water leaves the surface, and the joint is also where water gets in. Post-Uri we tightened the expansion-joint spacing on primary terraces from the trade-standard 20-to-24-foot interval down to a 16-to-20-foot interval, depending on orientation and substrate depth. We detail expansion joints with a compressible backer rod and a freeze-tolerant sealant selected for elongation rather than hardness. Every penetration — light fixture, irrigation stub, drain — gets a flexible collar rather than a rigid mortar seal. The discipline is simple: assume the stone will move a sixteenth of an inch across a fifty-degree temperature swing, and detail the joints to carry that movement silently.
For the full resilience treatment, see the Resilience section.
TYPOLOGIES
Four hardscape typologies.
Terrace
Terrace scale follows the house. We size the primary dining terrace at a proportion that reads as room-scale — typically a 14-to-18-foot primary dimension against a 12-to-16-foot secondary — set at a grade that lets water fall away from the house at a minimum 1.5% slope across the surface. Finish floor is coordinated with the interior threshold so there is not a sudden step-down, and the terrace is drawn against the existing canopy so shade patterns carry across the calendar year. The terrace is where the house becomes the garden; it carries the outdoor-living register and is typically detailed in that drawing set.
Wall
Walls are one of three things: retaining (structural against grade), seating (coordinated with an adjacent terrace at an 18-to-20-inch cap height), or site-defining (establishing a line without resisting load). All three take the same masonry discipline but different footing and batter. Lueders block at a chopped face reads well for naturalistic register; sawn coursing suits a more architectural context. The cap stone is drawn in section, not left to the mason, and the batter is documented before work begins.
Path
Path width is proportioned to use-frequency and to the architectural line it connects. A primary axis that carries daily foot traffic wants 42 to 48 inches; a secondary route wants 30 to 36; a service path can drop to 24. Material follows use: DG or pea gravel where the register is casual, Lueders or bluestone where the path is a primary architectural gesture. The edge treatment is drawn — steel header, stone band, or hard cut into an adjacent surface.
Step
Step risers run 6 to 7 inches; treads run 13 to 15 inches — proportions that read as comfortable on foot rather than institutional. Where a grade change exceeds 3 feet, we break the run with a landing rather than carrying a continuous flight. Material is held consistent through the whole step run: if the terrace is Lueders, the treads and risers are Lueders. Changing stone mid-step reads as a material accident and undercuts the composition.
Pool coping is a fifth hardscape typology with its own rules; see Pools & Spas for how coping reads against the wider terrace.
SELECTED HARDSCAPE WORK
![[OPERATOR: alt text in register per §9.9 — describe the specific planting/hardscape/architectural condition shown, e.g., "Live oak canopy over Lueders limestone terrace, Highland Park estate"]](/images/projects/modern-masterpiece/001_hero.webp)
2024 · [OPERATOR: neighborhood per D-5]
[OPERATOR: proper-noun title per D-13, e.g., "Modern Masterpiece"]
[OPERATOR: 2–3 sentence project intro per D-23 schema]
![[OPERATOR: alt text in register per §9.9 — describe the specific planting/hardscape/architectural condition shown, e.g., "Live oak canopy over Lueders limestone terrace, Highland Park estate"]](/images/projects/cradlerock-circle/001_hero.webp)
2024 · [OPERATOR: neighborhood per D-5]
[OPERATOR: proper-noun title per D-13, e.g., "Cradlerock Circle"]
[OPERATOR: 2–3 sentence project intro per D-23 schema]
![[OPERATOR: alt text in register per §9.9 — describe the specific planting/hardscape/architectural condition shown, e.g., "Live oak canopy over Lueders limestone terrace, Highland Park estate"]](/images/projects/modern-backyard/001_hero.webp)
2024 · [OPERATOR: neighborhood per D-5]
[OPERATOR: proper-noun title per D-13, e.g., "Modern Backyard | Alterra Design LLC"]
[OPERATOR: 2–3 sentence project intro per D-23 schema]