Know your concrete
Is it concrete block hollow cell? Poured cell? Concrete slab? What is the PSI? Not all anchors are created equal for every type of concete. Make sure you know exactly what you are fastening into and choose the right anchor.
Tapcons are light duty
Your typical threaded “tapcon” is for light duty tasks. While a tapcon may be fine to hold down a condenser (that already want to stay down), it would probably (definitely) be the wrong option for mounting a heavy motor assembly to the wall. For big jobs go with a tougher anchor. Hint: if it has threads and you “screw” it in, it probably isn’t the toughest option.
Anchors embedded too shallow
Most concrete anchors have a minimum embedment depth. You can usually embed deeper but you you need to at least hit the minimum, read the directions.
Anchors too close
All anchors have a minimum distance they can be from one another. If you get them too close the whole kitten kaboodle can pull right out on you (I’ve done this).
Wedge anchors (Red Heads) are a common heavy duty anchor. When drilling the hole wrap electrical tape on your bit at the depth you want to go so you don’t overdrill the hole or worse…. blow out the other side.
Clean the hole
With a wedge anchor the dust in the hole can act like a lubricant, making it easier for it to pull out. When done drilling use a round bottle brush or vacuum to clean the holes out. This is especially true when using an epoxy “chemical” bolt.
Warbling the bit
With concrete anchors, use the right size bit and run it straight it. No warbling the bit around… unless your desired result is having the anchor pull out and destroy a monastery, then warble away.
Torque it down
Sorry, you do really need a torque wrench, especially if you are working with large wedge anchors. Torque that sucker down to factory specs and you won’t need to worry. Keep in mind, you may wanna retorque it after it’s been put under load a few times, especially in safety critical applications.
Don’t overload it
Before you get started make sure you know the Ft/lbs of force the anchor will be under and play on the safe side. Like GI Joe says… now you know, and knowing is just scratching the surface.
P.S.- you can watch a video on wedge anchors HERE