Model expansion, contraction, seismic drift, and tolerance precisely. Review design and maximum joint movement scenarios. Create safer gaps, seals, and details for demanding projects.
Thermal movement: ΔL = α × L × ΔT
Total thermal opening: left opening + right opening at the minimum service temperature.
Total thermal closure: left closure + right closure at the maximum service temperature.
Service opening demand: thermal opening + shrinkage opening + seismic opening.
Service closure demand: thermal closure + moisture swell closure + live load closure + seismic closure.
Factored demand: service demand × (1 + safety factor).
Recommended nominal width: the larger of minimum safe install width and seal-capability-based width.
Resultant transverse movement: √(shear² + vertical²).
| Scenario | Installed Width (mm) | Left Length (mm) | Right Length (mm) | α Left/Right (ppm/°C) | Install Temp (°C) | Min / Max Temp (°C) | Recommended Width (mm) |
|---|---|---|---|---|---|---|---|
| Parking Deck Slab Joint | 30 | 6000 | 6000 | 12 / 12 | 20 | -10 / 60 | 35.160 |
| Facade Panel Joint | 20 | 3500 | 3500 | 10 / 10 | 18 | -5 / 45 | 22.780 |
| Roof Perimeter Joint | 40 | 9000 | 9000 | 11 / 11 | 25 | -15 / 70 | 52.360 |
It estimates joint opening, closure, total movement range, minimum safe install width, recommended nominal width, and seal utilization using thermal and additional project movements.
Adjacent elements may differ in span, restraint, or material. Separate lengths and coefficients let you model asymmetric movement more realistically.
Seal capability is the allowable movement as a percentage of nominal joint width. A ±50% seal can usually move half the width in opening and closure.
Yes, when you already have project seismic displacement values. Enter opening and closure demands directly to combine them with thermal and service movements.
Tolerance reduces real clearance. Even a well-sized joint can close too much if field installation shifts the opening smaller than intended.
It shows how much gap remains after factored closure and tolerance are considered. Negative clearance suggests contact risk and a larger joint may be needed.
No. It is a design aid. Final product selection should still follow manufacturer data, project specifications, fire ratings, waterproofing needs, and movement class limits.
Increase it when uncertainty is high, restraint assumptions are weak, site temperatures are harsh, or long-term movement inputs are preliminary.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.