# LDD-22 · Basketball Hoop System

> **Status:** 🟢 LOCKED.

## One-line intent

No wall-mounted load — independent slab-anchored steel goal frame.

## Why this matters

A wall-mounted hoop puts dunking loads (~1,200–2,500 lbs impact) into a structural wall. A slab-anchored independent frame puts it into the slab. The latter is correct for a serious basketball court — both for performance and to keep the spine wall / hero wall designs clean.

## Locked decisions

**Core rule**

- **No wall-mounted load.**

**System**

- Independent steel goal frame
- Anchored to slab
- Load path: backboard → steel → slab

**Performance**

- Dunk-rated
- No vibration
- Professional feel

## Open items / requires engineer review

- **Frame manufacturer + model** — Goalrilla, Spalding 888, Mammoth, First Team Sport II, Schelde, Bison. Wide range from $1.5K residential to $12K commercial.
- **Backboard** — tempered glass (72") for pro feel; acrylic for cheaper. LDD-04 implies 72" tempered glass.
- **Rim** — breakaway pro rim (e.g., Spalding Heavy Duty Spring) for dunk performance.
- **Anchor detail** — typically 4 bolt anchors set in slab during pour. The anchor pattern must be specified BEFORE slab pour; retrofitting requires core drilling and epoxy anchors (less ideal).
- **Retraction strategy** — fixed cantilever, or retractable (winch-folded) to clear the gym for other uses? Retractable adds $4–10K but transforms the gym's flexibility.
- **Single hoop or two (full court)?** A 60'-wide gym fits a half-court easily; full-court basketball needs ~84' baseline-to-baseline (NBA 94', college 84'), which is the building length (120') — feasible, would need two goals.
- **Court line painting** spec (LDD-24 flooring) — coordinate.

## Cross-references

- ← [LDD-04 west gym hero wall](04-west-gym-hero-wall.md) — central 12' no-glass zone exists because of backboard placement.
- ← [LDD-24 flooring](24-flooring.md) — urethane gym floor + slab anchorage detail.
- ← [LDD-01 structural](01-structural-pemb.md) — slab thickness must accommodate hoop frame anchorage.

## Cost drivers

- **Pro-grade slab-anchored hoop system** with 72" tempered glass backboard and breakaway rim: $4–12K residential-pro, $6–18K commercial-pro.
- **Retractable mechanism** if chosen: $4–10K additional.
- **Anchor + slab preparation**: $0.5–1.5K (designed into slab pour).
- **Second hoop for full court** if added: $4–18K.
- **Court lines + sport markings** on urethane floor: $1.5–4K.

**Likely-case rollup: $8–14K for single fixed hoop; $16–35K for retractable full-court setup.** Currently budgeted within "Workshop+lift $95K" line — recommend breaking out separately.

## Air-gap concerns

1. **Anchor pattern must be set before slab pour.** Retrofitting via core drill + epoxy works but is less robust under repeated dunk impact. Specify the chosen system early so anchor template is in the slab pour.
2. **Slab thickness under hoop.** For dunk-rated impact, the slab under the hoop frame should be a beefier section — typically 8" thick with #4 rebar at 12" OC, vs 4–6" elsewhere. Coordinate with structural.
3. **Backboard clearance to clerestory** when retracted (per LDD-04). Verify retraction kinematics don't hit clerestory mullions.
4. **Two-hoop full court** sounds great but the gym is only 60' E–W and ~60' N–S (central core). True full court (84–94' baseline) won't fit. A practice court (43' length, half-court) easily fits.
5. **Net spec.** Standard cotton nets shred quickly; chain nets are louder but durable; pro nylon nets are best. Buy spares.

## Diagram

(see [west gym elevation](../../diagrams/04-west-gym-elevation.svg) for backboard placement.)

## Status

🟢 **Green — the right structural choice.** Lock specific hoop model + anchor pattern before slab pour.