How do I destroy spiked walls most efficiently?
The Rust wiki said that Spike Walls are structures that can be placed on various terrains (no Foundations needed). A newly placed spiked wall has 375 HealthPoint (HP). Using that information the Rust wiki has made a small diagram containing how long it would take for melee weapons to break this.
5HP per Rock - 75 Hits 3HP per Stone Hatchet - 125 Hits 6HP per Hatchet - 62.5 Hits 15HP per Pickaxe - 25 Hits
This on its own would be an answer to your question however the game has a decay feature.
If they are decayed, the hits would be less. How much health decays over time is not stated on the wiki but if it decays on a steady pace you could do the math.
After 24 hours:
250HP remaining 5HP per Rock - 50 Hits 3HP per Stone Hatchet - 82 Hits 6HP per Hatchet - 41 Hits 15HP per Pickaxe - 17 Hits
After 48 hours:
125HP remaining 5HP per Rock - 25 Hits 3HP per Stone Hatchet - 39 Hits 6HP per Hatchet - 20 Hits 15HP per Pickaxe - 9 Hits This is speculation since i couldn't find any proof about the decaying of items (besides that they decay).
The only thing the wiki states is :
A spike wall will decay over time and can be repaired using wood on your hotbar. Equip the wood to your hotbar and use that corresponding key while facing the spike wall. Per wood it will repair the wall for 50 hp (up untill its maximum). If left to decay the wall will be gone within 2-3 days.
So if you place the spiked wall on the ground and login after two days you could simply repair it with a few pieces of wood.
Shooting the spiked wall with a bow does actually damage the wall since arrows count as melee damage. This however is a known bug since the player does actually take damage as he would when hitting it with a 'regular' melee weapon.
When on foundations or ceilings, spike walls do not decay as they're treated as part of the house.
As stated before Explosive charges (C4) can also destroy the spike walls. The damage and amount needed are not stated on the wiki so more research is needed.