PROJECT 12 / SUPPORTS & JOINTS
These examples calculate forces from selected drawing outlines. Supports and extra loads are assumed so the options can be compared.
Support positions, load cases, fixings and joint details were not supplied. The following examples are created for comparison; they do not establish that any completed job or proposed installation is safe.
How to read these forces → · Drawing gaps for this project →
Each outline has its own drawing. Open a component to see its forces, assumed supports and worked calculations.
Results are per physical piece; quantities are shown separately. Alternative drawing sheets are not added together. Horizontal surface examples add an illustrative 500 N point load to stone self-weight; trim strips and vertical panels use self-weight only.
| Component / source | Thickness basis | Scenario mass / gravity | Support demand | Strength check |
|---|---|---|---|---|
| Folded surround top faceproject-12.jpg · qty 1; results per piece | 20 mmdrawing reading | 6.9 kg67.9 N self-weight | R₁ 283.9 N R₂ 283.9 N | UnverifiedDemand only; resistance not established |
| Folded surround two side facesproject-12.jpg · qty 2; results per piece | 20 mmdrawing reading | 10.1 kg98.7 N self-weight | Ledger 98.7 N Restraint couple 31.1 N | UnverifiedDemand only; resistance not established |
Gross dimensions remain unverified drawing readings. Assumed 20 mm thicknesses and proxy densities are identified in every worked record. These scenario inputs do not replace the fixed measurement tables.
Gross area 0.1442 m²; thickness 20 mm (drawing reading); density 2,400 kg/m³ (Estimate · comparable quartz). Openings are not deducted; cutout stress concentrations and remaining stone strips need a separate check.
m = A × t × ρ = 0.1442 × 0.020 × 2,400 = 6.92 kg
W = m × 9.81 = 67.88 NAssumed end support lines: x = 0 and L = 0.9080 m
Gross-outline centre of mass x̄ = 0.4540 m
Illustrative additional point load P = 500 N at x = L/2
R₂ = (W × x̄ + P × L/2) ÷ L = 283.94 N
R₁ = W + P − R₂ = 283.94 N
Check: R₁ + R₂ = W + P = 567.88 N500 N, where included, is an example load (about a 51 kg mass equivalent), not a prescribed residential design load. Trim-strip examples use self-weight only. The end-line model is a statics exercise: it does not permit this stone to span the full length. Actual rails, cutouts and supports can create a different load distribution.
If the right edge is a supported butt seam, this piece contributes 283.9 N to its support in the assumed load case. Add the adjoining piece’s edge reaction and applicable loads before selecting that support. No actual seam position or adjoining load is confirmed.
Capacity pending: stone bending and deflection, local bearing, support stiffness, joint shear/peel, connection capacity, load factors and the final design load combinations are not established. A bond area or an adhesive coupon strength alone cannot establish the installed joint’s capacity.
Gross area 0.2097 m²; thickness 20 mm (drawing reading); density 2,400 kg/m³ (Estimate · comparable quartz). Openings are not deducted; cutout stress concentrations and remaining stone strips need a separate check.
m = A × t × ρ = 0.2097 × 0.020 × 2,400 = 10.06 kg
W = m × 9.81 = 98.73 NLower bearing demand R = W = 98.7 N
Assumed offset e = 0.030 m; restraint separation h = 0.0953 m
M = W × e = 2.96 N·m
T = M ÷ h = 31.10 NThe assumed separation is the smaller of 300 mm and 60% of the panel’s short outside dimension. This keeps the example couple within its outline; it does not establish anchor placement or edge clearances. The forces form an idealized upper-restraint/lower-bearing couple for one panel. They are not individual anchor capacities. Anchor prying, shared load, substrate strength and lateral/seismic loads are unassigned.
The bottom joint or ledger must transfer at least the 98.7 N modeled gravity demand from this panel, plus other applicable design actions. Adhesive-only suspension is not assumed.
Capacity pending: stone bending and deflection, local bearing, support stiffness, joint shear/peel, connection capacity, load factors and the final design load combinations are not established. A bond area or an adhesive coupon strength alone cannot establish the installed joint’s capacity.
This example uses TP6610 at 20 mm and 2,400 kg/m³. It does not claim this overhang exists in Project 12. A 350 mm overhang, 400 mm tributary width and 500 N tip load are deliberately assumed.
W_bay = ρ × t × 0.400 × 0.350 × 9.81 = 65.92 N
V = W_bay + 500 = 565.92 N
M_root = W_bay × 0.350/2 + 500 × 0.350
= 186.54 N·m
For a separate ideal connection with h = 0.150 m:
T_couple = M_root ÷ h = 1,243.58 NThe 150 mm force-couple lever arm is an algebra example for a vertically separated connection. It is not the Liberty’s flush-mounted lag-screw geometry or an anchor specification.
Published carry reference: 375 lbf per bracket ≈ 1,668 N. The bracket has a 12 in support projection plus 4⅛ in mounting length, with a 3 in width and ¼ in steel thickness.
Its guide calls for double 2×4 knee-wall blocking tied into the floor, flush/level mounting and spacing no greater than 18 in (457 mm). The 400 mm example bay is within that spacing figure. The assumed 350 mm overhang extends about 45 mm beyond the 305 mm arm; permissible stone extension still needs confirmation.
Comparison, not approval: the calculated 566 N shear is 33.9% of the catalog force reference. The guide does not establish the actual anchor-group moment resistance, stone capacity, test load position or an applicable design safety factor. Those checks remain open.
Required resistance must cover the governing design demand on a consistent load/resistance basis. These pages calculate selected service-load demands; they do not supply tested allowable capacities or a code-compliant design factor. Stone cracking, deflection and joint failure therefore remain unresolved.
Force balance and moments use algebra: ΣF = 0 and ΣM = 0. No calculus is required for these demand examples.
Manufacturer tables apply only within their stated products, thicknesses, regions and installation conditions. They are not copied into a universal allowable-span rule. Research checked 24 October 2026.
Download assumptions and calculation record ↓