Truncated Domes
How to Install a Cast-in-Place Truncated Dome (2026 Guide)
Cojo
May 7, 2026
8 min read
A cast-in-place truncated dome panel is the new-construction install method where the panel is set into wet concrete and finished flush with the surrounding walking surface. When done right, it produces a 50-year detectable warning surface that meets ADA Standards 705.1 dimensions (0.9 to 1.4 inch base, 0.2 inch height, 1.6 to 2.4 inch on-center spacing) and resists every failure mode that retrofit surface-applied panels eventually face. This guide walks the full install in 8 steps with the time, tools, and code citations Cojo's crews use on Oregon curb-cut and platform-edge jobs.
For the broader product comparison see our truncated domes guide, and for retrofit method see cast-in-place vs surface-applied.
> Compliance disclaimer: Always verify current detectable warning requirements with your local jurisdiction. This article reflects 2026 federal ADA Standards (28 CFR Part 36, Appendix B) and ADA Accessibility Guidelines 705. State and local supplements may apply.
A cast-in-place dome panel ships as a pre-formed composite or polymer-concrete tile with a textured back face and integral anchor lugs. Crews set the panel into freshly placed concrete during the pour, screed and float around the perimeter, and let the surrounding slab cure with the panel locked in. The result is a one-piece walking surface where the dome field is mechanically embedded rather than glued on top.
| Factor | Cast-in-Place | Surface-Applied |
|---|---|---|
| Lifespan | 30 to 50 years | 8 to 15 years |
| ADA 705 wear performance | Stronger (705.5) | Adequate with maintenance |
| Adhesive joint failure risk | None | Edge lift, water intrusion |
| Best application | New construction, full ramp pours | Retrofit, existing curb cuts |
| Install window | Day of concrete pour | Any cured slab |
Before the concrete truck arrives, stage these on site so the crew is not chasing a missing item once the slab is workable:
A standard 4-foot-by-2-foot single-panel curb cut runs 35 to 60 minutes of finishing labor on top of the underlying ramp pour. A 2-person crew is the minimum (one screeds, one places and levels the panel). For a 6-panel transit-platform edge, plan a 3-person crew and a 4-hour window from pour start to broom-finish.
Before the truck pours, confirm the curb-ramp form geometry matches ADA 406 ramp slope (1:12 maximum) and the panel pocket depth equals the panel thickness plus 1/8 inch tolerance. Most cast-in-place panels run 1 inch thick. Forming a deeper pocket lets the panel float as the concrete settles. ADA Standards 705.3 require the dome field to span the full curb-ramp width and 24 inch minimum depth.
Pour concrete into the curb-ramp form in a single continuous lift. Strike off with a screed board to the finish elevation. Bull-float once to bring paste to the surface. Do not over-work — the panel must seat into plastic concrete, not soup.
Carry the panel by the edges (the dome face has the smallest tolerance for damage). Lower it into the pocket dome-side up, square to the curb edge per ADA 705.3 placement (set back no more than 8 inches from the curb edge for diagonal-style ramps; flush to the bottom for perpendicular ramps).
Tap the panel into the wet concrete with a rubber mallet, working corner-to-center to displace air pockets. The dome field must finish flush with the surrounding walking surface to within 1/8 inch on a 4-foot straightedge. Verify with a 4-foot level laid across the panel onto adjacent concrete. Re-tap any high corner.
Hand-float the concrete tight to the panel edge. Pull a tooled groove or sawcut joint where the panel meets the larger slab so the joint controls future cracking. Edge the curb-side return at the standard 1/2 inch radius. Avoid working concrete onto the dome surface — masking with painter's tape during the float pass keeps domes clean.
Once bleed water has dissipated, apply ASTM C309 cure compound at the manufacturer's coverage rate (typically 200 to 250 sq ft per gallon) using a low-pressure sprayer. For freeze-thaw climates like Bend or Hood River, follow with a curing blanket overnight.
Barricade the panel area for 72 hours minimum (24 hours for foot traffic, 7 days for vehicle loads). Tape signage warning of fresh concrete. In ambient temperatures below 50 degrees F, extend the cure to 96 hours.
Pull the barricades and run the final ADA verification:
Any panel out of tolerance must be removed and replaced before the slab cures harder than 1,500 psi or saw-cut removal becomes the only option.
Industry Baseline Range
| Item | Range |
|---|---|
| Panel material (24 in by 48 in composite) | $180 to $320 |
| Panel material (cast-iron embedded) | $400 to $700 |
| Labor per single-panel curb cut | $200 to $450 |
| Single-panel curb cut, installed | $380 to $1,050 |
| Transit platform edge per linear foot | $90 to $180 |
2026 cast-in-place installs run higher than the baseline above for two reasons. First, ADA-rated composite panels saw a 12 to 18 percent material cost lift after 2025 polymer feedstock disruption. Second, Oregon labor for ramp finishing carries a premium during paving season (May to October) because concrete finishers are pulled to highway and parking-lot work. Plan a 10 to 20 percent contingency on top of baseline if the install is on the critical path of a building turnover.
You cannot cast-in-place a retrofit unless you are willing to remove and replace the existing curb-ramp slab. For active sidewalks, transit platforms, or parking lots where the ramp concrete is intact, surface-applied panels with epoxy and mechanical anchors are the standard retrofit. See cast-in-place vs surface-applied for the full retrofit decision tree.
Three sections of ADA Standards govern every install:
The full text lives at the U.S. Access Board's Chapter 7 Communication Elements and Features and 36 CFR Part 1191. For Oregon-specific wrap-around requirements that affect curb-cut placement at parking-stall paths, see our ADA parking requirements Oregon article.
Cause: pocket depth was set wrong, or the panel was not tapped down before the slab took initial set. Fix: catch it before final set; otherwise the panel must be cut out.
Cause: concrete was over-finished and brought too much paste up. Fix: re-strike the perimeter and groove the joint earlier.
Cause: surrounding concrete was not color-matched to the planned contrast pair. Fix: at panel order, calculate Light Reflectance Value (LRV) of adjacent walking surface. A standard gray sidewalk LRV runs 25 to 35; a yellow dome LRV runs 70 to 80, comfortably exceeding the 70 percent contrast threshold per 705.2. Brick-red domes (LRV 12 to 18) need a light walking surface — a problem for many gray-on-gray spec mistakes.
On a 2026 sidewalk reconstruction near the Capitol Mall in Salem, Cojo set 14 cast-in-place yellow composite panels across 12 curb cuts. Two panels failed the 4-foot straightedge test on first set because the sub-grade had compacted unevenly. We removed and re-poured the affected pockets the same morning. Total project window was three days for placement and one week of cure before pedestrian traffic returned. Inspector verified all 14 panels against ADA 705.1, 705.2, and 705.3 — no callbacks.
For a Salem-specific install bid, see Salem truncated dome installation.
Cojo installs cast-in-place truncated dome panels for parking-lot ramps, sidewalk curb cuts, transit platforms, and ADA path-of-travel retrofits across Oregon. Every install is verified against ADA 705 and documented for compliance audits. Contact Cojo for a site-specific quote.
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