Editing Openai/6928dffa-2c40-800e-b585-2520d50a2cbb (section)

=== Key specs & performance comparisons (typical ranges / manufacturer claims) ===
* Setting & cure time - Foam: initial set often 3–30 minutes; final cure often within 1–2 hours (product dependent). You can usually start building much faster than with concrete. Sika USA<ref>{{cite web|title=Sika USA|url=https://usa.sika.com/retail/en/products-catalog/post-setting/sika-postfix.html|publisher=Sika USA|access-date=2025-11-28}}</ref> - Concrete: initial set hours (can be walkable in 24 hrs for small mixes), full strength in days; you typically wait 24–48+ hours before loading heavily. Bob Vila<ref>{{cite web|title=Bob Vila|url=https://www.bobvila.com/articles/expanding-foam-vs-concrete-fence-post/|publisher=Bob Vila|access-date=2025-11-28}}</ref>
* Compressive / lateral performance - Foam manufacturers often compare their product to tamped soil (foam sometimes claims 3–4× the compressive strength of tamped soil and lateral resistance figures like “resists >500 lb lateral force” for certain fence products). These are useful for comparing against soil, not necessarily against cured concrete. Fast 2K<ref>{{cite web|title=Fast 2K|url=https://fast2k.com/|publisher=Fast 2K|access-date=2025-11-28}}</ref> - Concrete (properly mixed and cured) generally provides much greater mass, stiffness and long-term compressive strength than generic post-foam — and concrete footings distribute loads into the ground more predictably for heavy or structural loads. Bob Vila<ref>{{cite web|title=Bob Vila|url=https://www.bobvila.com/articles/expanding-foam-vs-concrete-fence-post/|publisher=Bob Vila|access-date=2025-11-28}}</ref>
* Weight & excavation - Foam: very lightweight (one bag expands and fills many cubic feet), easier to handle, no heavy wheelbarrows. Sika USA<ref>{{cite web|title=Sika USA|url=https://usa.sika.com/retail/en/products-catalog/post-setting/sika-postfix.html|publisher=Sika USA|access-date=2025-11-28}}</ref> - Concrete: heavy, permanent mass — good where mass and rigidity are required. Bob Vila<ref>{{cite web|title=Bob Vila|url=https://www.bobvila.com/articles/expanding-foam-vs-concrete-fence-post/|publisher=Bob Vila|access-date=2025-11-28}}</ref>
* Code & approvals - Some foam products (e.g., certain Fast2K items) carry ICC-ES or IBC/IRC guidance for specific load-bearing deck anchors; others (Sika PostFix) explicitly say not recommended for structural applications like decks/playground/basketball poles. Always match the product PDS to the intended use and check local code. Fast 2K<ref>{{cite web|title=Fast 2K|url=https://fast2k.com/|publisher=Fast 2K|access-date=2025-11-28}}</ref>