Poison Spell Can't Take Damage in Building

Supercell,

The Poison Spell is not take Damage in Building but it can Poison Enemy Troops and Heroes.In (Clash Royale) the Poison spell can get Damage in Building and Poisoning Troops.The Poison is Not too Useful but In Lower Town Hall they Use for Enemy Troops or Heroes.

English is my second language, but I can tell there is plenty of grammar mistales

As i understand of your broken grammar (correct me if i got it wrong) poison does not damage buildings at all and it is the concept of poison.

I don't get where you got the "poison spell can't damage buildings" thing. I think you recently unlocked the spell. It's meant for CC (clan castle) troops. Players who use it on heroes doesn't make much damage. That's what that spell was meant to be, just like EQ (earthquake) spell for example, it's meant for walls, yet, some use it to destroy buildings at a very low hit points.

poison in clash royale should not damage buildings but this is a problem of the other game