What are some powerful anti-construct spells that target Fortitude?

Question

What Fortitude-targeting spells are big threats to Constructs?

I'm curious about spells that are strong versus constructs. I'm particularly curious about ones that target Fortitude (since they count as having a 10 CON vs the Fortitude-targeting spells).

Obviously constructs are immune to Fort spells "unless the effect also works on objects"...but I'm curious what some of the dangerous spells are in that category. This is for a level 20 game, so I'm curious about any Paizo spell, including highest level spells.

Answer 1

Disintegrate

Disintegrate can hit objects, has a Fort save, and deals 2d6 per caster level up to a whopping 40d6.

Shatter. This is extremely narrow, and does not hit all constructs, only small, crystalline ones, but otherwise checks all your boxes: Fort save, can target objects, and the d6 damage per caster level (up to 10d6) is also solid for a second level spell.

If you are not only looking to damage constructs, the following spells might be worth a look:

• Antitech Field
• Control Construct
• Disable Construct
• Sabotage Construct
• Drain Construct
• Fleeting Defect
• Malfunction

Answer 2

This is just an obscure addition to Groody's good answer:

If you play an Impossible bloodline Sorcerer, then you can use a Fetish of the Frog Queen with your compulsion spells to target the Fortitude save modifier. However, the spell is still considered targeting the Will save (just uses the Fort modifier), so the construct immunity to Fort saves does not apply.