Doors and Windows - Threshold on Exterior Door

In a house we've just bought there is an external door where
the laminate flooring goes right under the door and outside.
Even I know better than that!

I checked at the local building supply store and saw several
different types of threshold, i.e. wood, aluminum. There
were also different shapes, and so on.

- Which material is best for exterior doors where there will
be both a storm door and a regular door?

- What shape should it be? There were some that were
D-shaped, others slanted outwards, some flat, and so on.

I would think it would need to slope towards the exterior for
water runoff, and the best materials would be those that
would neither rot, bend, break, or wear from being stepped on.

Lastly, how do you install it?

Thank you,
Larry
:confused:

Select the type of threshold that looks good to you with your entrance.
I personally have the aluminum with the rubber D strip. It's more for air seal than water, because my storm doors keep the water out.
You can trim off the bottom of your wood door to make it seal on the D strip.
You hacksaw off the threshold to fit the width, screw the threshold down through its pre-drilled holes, and pop the D strip in the track.
You can get just the rubber D strip to replace it when it wears out.
Good Luck!
Mike