Carpenters, woodworkers, handymen: most durable finish for exterior threshold?

I’m replacing an old painted wooden threshold on our front door with a new oak one, and looking at finishes that will keep it from chipping and wearing away like the old one has. But many of the polyurethane finishes intended for exterior use say, “not for high traffic areas.” So maybe they’re only for furniture and fences and things that won’t be walked on.

So I’m trying to figure out whether oil-based or water-based is better, or whether to use this supposedly eco-friendly stuff, which also comes in another flavor. But it’s just not clear to me which (or which combination) would be best for my purposes.

What do you suggest?

I’ve always used Spar Varnish for those kinds of applications, but that may be considered ‘old school’ at this point.

There’s nothing that lasts forever. Polyurethane is extremely durable (can take foot traffic indoors for decades), but outside, the UV will eventually degrade it. So, you just need to plan on re-finishing it every decade or so.

Spar Varnish or Spar Urethane are the ‘new school choices’. Spar Varnish requires several coats for a long lasting finish. Oil based versions replenish old wood and all forms should have higher absorption into wood than other products so they do not readily peel off the wood.

I think it would depend on what type of climate you are in. Dry vs. Humid, wind, heat, cold, snow. You get the idea.

I agree an exterior polyurethane is a wise choice.

For exterior woodwork, I usually buy from a chandlery - not just hardware store ‘yacht varnish’, but finish intended for use on actual marine vessels.

I use Spar Urethane.

It still can’t withstand the Western sun. I have to recoat my front door every 5 years. The finish withers and disappears from the direct sun. I’ll have bare wood spots within 7 years.

Echoing the spar varnish, but it will fail like every other finish eventually. If you can get a new oak sill in, can you retrofit a powder-coated aluminum sill? Not traditional, but it’s 100% maintenance free.

Actually, they’re anodized (fwiw).

That’s what we have in the back, but my wife wants something nicer for the front. The existing threshold is painted to match the shutters, but it started rotting and the paint flaked off. And there’s no silver-ish metal around the door that an aluminum threshold would match.

Well, no, I don’t get the idea, or I wouldn’t have asked. I mentioned that we are literally on the ocean in Massachusetts, so a few very hot days in the summer, plenty of cold and snow in the winter, humid for much of the year, and the occasional Nor’easter (multi-day storm with high winds and heavy rain).

Water-based, oil-based, quick-dry, slow-dry, eco-friendly, or not?

You’re on the coast in a very unforgiving environment. The previous advice to go to a shipyard/chandlery and get the most noxious oil-based spar varnish they have is good advice. Follow all the prep direction and do 3 coats. When it starts to fail, sand and recoat ASAP.

How about a marble threshold? Very traditional, not too pricy, good for life?

That is an excellent idea that I had not even considered!

We had a new pathway installed last year, and the steps and stoop below this threshold are marble, so I know where to go to get more of the same. As long as they can cut it to the proper dimensions for me, all I have to do is figure out how to permanently install it. That will probably be a lot easier, simpler, and quicker than finishing the wood threshold.

I hope the lumber yard will let me return the oak one.

Thanks again.

They should drill and countersink 3 holes for mounting. What is it sitting on top of?

I replaced the old threshold on my log cabin with one I cut from pressure treated lumber, so there’s another option. You should probably use a silicone sealant on the marble if it’s real stone.

If the stone yard can’t shape it (they should be able to), any counter fabricator could cut and polish it in a hour or 2. Sounds like an ideal solution given the pathway and steps!

Also, for mounting the answer is always Sika

If the marble doesn’t work out, another thing to consider is a bronze bullnose.Covers the outdoor part of the oak, so no UV finish breakdown. Works like a wear strip, so the threshold doesn’t get that reverse bell curve wear pattern for a century or two. You gotta like the appearance of verdegris, though, and it is jeezly expensive.