So I followed a tutorial to add a custom barricade to my map, I made a metal bar one rather than wood boards,
it works perfectly, however after adding this my map that used to run constant 60FPS now runs barely 30 and even hits 20... I restarted my pc, closed all my open apps, caulked a load of textures and the framerate still sucks, Ive no idea what could have caused this or how to fix this... please help

after first play after adding the barricade another part of my map had "teleported" to my start room and intersected it although I could walk through the "teleported" brushes, I fixed this by deleting the old brushes that had "Teleported". Im unsure if this could have caused the framerate to drop for my whole map

Hmm...that's odd. Try undoing the custom barricades and then check your framerate. Just to see if thats what's causing the problem