Stormin Mormon wrote:
On 12/24/2013 6:57 PM, philo wrote:

They are called "concrete screws"

I use them all the time and they are great. Most any H/W store will have
them. (They come in either flat head or hex head)


BTW: Don;t get the ones made out of concrete though (yes another one of
my stupid jokes)

Whew. Glad they are available. Are they near the
lead free lead anchors?


As others have said, Tapcon is a common brand of concrete screws. If you
haven't used them before, you might want to try them in a similar situation
to your job before you try them in "real life".

There are 2 types. Flatheads, for which you should countersink the
threshold, and hex head which will end up with the head proud of the
threshold. You might not want that, unless there's a track or groove that
will keep them below the surface.

One key tip: Tapcons are essentially a one shot deal. If you spin them in
too fast you can strip the hole. Once you do that, you can't use that hole
again unless you fill it with epoxy or something. You also usually can't
loosen the fastener and tighten it again. Concrete isn't as forgiving as
wood in that regard. It's basically "a screw them down tight and leave them
alone" operation.

I mention all this because the fasteners will be visible. If you mess one
up, you might have to drill another hole in the threshold which will also
be visible.

Check out this video:

www.youtube.com/watch?v=djotP-sR4mU