I am installing a Kahrs Woodloc floating floor and quickly approaching the front door which has a metal frame at the bottom. The flooring will be installed perpendicular to the door. I've been doing some research at Hardwoodinstaller and found that there seems to be two ways to make the transistion at the door:

1) Undercut the metal door threshold and slip the boards underneath. I like this idea as it seems that would be a clean looking install. Though, what too do I use to undercut? Door a put a metal blade on a doorjamb saw? Secondly, would downward pressure from people stepping on the threshold cause damage to the flooring at some point (most will step over I guess)? Any potential moisture issues?

2) Taking the flooring up to within a half-inch and putting a molding strip across the top OR stopping the flooring over an inch short and using a square nose piece of trim. Though, with the square nose, the ends of the molding would be visible as the trim on my door is not very deep (would not protrude enough to fit the square nose from side to side).

What I was going to do was take the Kahrs to about 1/2 inch from the metal threshold and try to craft a small trim strip to cover the gap. The distance from the top of the flooring to the top edge of the metal threshold is roughly 3/8ths (maybe 1/4). Not really sure how to do that nicely or even if could be done correctly. I'm leaning towards #1 above, but would like some more direct advice on the subject.

One more option, I suppose, is to butt the flooring against the threshold and fill the small gap with color matched caulk. This was mentioned in another post and seems like a good idea. I guess the Khars does not expand much lengthwise, but how much gap would be required for this method?

TKS.

This photo shows how thin the door trim actually is:

If I were installing this floor, the way I would do it would be to undercut the wood molding (casing) the thickness of the factory end cap (square nose). Then hold back the floor about 1" starting at the casing all across the front of the door. IMO, your door consists of the door metal threshold plus the two side panels and casings. I'd install a square nose all across that area and under the casings on each side. Where the square nose cut sticks out past the casings, I'd make a round over (or 1/4 circle) to make it more attractive and custom looking.

Another way to finish it off is to have the end moulding return to the threshold by cutting a 45 and putting a small return piece. It gives it a finished off look so you don't have to look at raw wood. This way you have your expansion and can silicone it for moisture. Just make sure you leave a little flooring sticking out past the casing (door side) so you don't have a void.

I stopped by a local wood flooring store to get a piece of square nose (for an area that meets carpet) and could not resist asking them about the front door transition. Right off, two different guys said that they would simply tuck the flooring under the side casings and butt the floor ends right against the metal threshold. At the threshold, they mentioned to get a straight, even cut and the use a color matched caulk to fill in. Now, I know these places probably go for the easier solution, but surely this would look acceptable or they would have complaints. Yes? More thoughts?

Gary and cerscott1, would you happen to have any pictures of your solutions? I'd really like to see something before I attempt to do it.

Can you replace the threshold with one that would go over the wood?

Those metal tresholds are often attached to the bottoms of the door jambs with screws that are inaccessable.
I don't have pics of what I was suggesting unfortunately. The problem with what those guys were suggesting (butt it tight) is twofold. 1) It does not allow for expansion, which a floater needs and 2) Since it's a floater, there's nothing to anchor the floor down at that spot.

I had a rotten sill plate I had to replace about a year ago. On top of the sill plate was a metal threshold. The way that both the one I took out and the one I replaced it with worked, was that you could remove the rubber weatherstripping and the screws that held it down were then accessable.

I don't know if this one is the same way. If so, it should be a relatively easy job.

Gary,
So I would install the square nose first, then slip the floor under (probabaly have to slide in from the side and glue vice use the woodloc mechanism). Or can I hold the floor back the one inch and the wriggle the molding under?

The threshold does not appear to be of the easily replaceable variety. I see no screws, hidden or otherwise.

Install the flooring first, holding back the 1" or more for expansion. Give yourself as much room as possible but not more than the molding will cover. Use a small piece of the square nose to check that the flooring cuts and placement are correct. Then after the floor is installed, install the trim. Slide one end all the way under one side of the casing then bend the molding up in the middle to allow it to fit under the other casing. Or cut the casings high enough to allow the square nose to be slide (wiggled) in.

Looks like that solution is my best option right now. I have put in an order for some Khars square nose and t-molding. I'll take a shot at the t-molding ripped in ~half lengthwise and compare to the square nose. I picked up a piece of unfinished square nose locally, but when I sanded and stained, the grain really popped out. Looked like a Zebra stripe and totally unacceptable.