Marble threshold between hardwood and ceramic?


Old 10-12-04, 12:41 PM
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Question Marble threshold between hardwood and ceramic?


Thanks to my young son of the errant aim , I have to replace the hardwood floor in our powder room. My plan is to replace with 12x12 ceramic tile on a diagonal (the room is only 5' x 5'). Here's the challenge I face:

The powder room is situated in the middle of a large expanse of hardwood flooring covering the hallway, foyer, dining room, and kitchen. The hardwood floor runs parallel to the powder room doorway so I can't do the standard "mixed floor" practice of butting the hardwood slats against the new material. In addition, the old hardwood floor was originally stained dark brown, but when we bought the place we sanded it back to the original red oak finish, though the deeper grains in the wood retain the dark stain. It looks fine, but any thresholds or reducers using new red oak would not match (though I guess we could replicate by staining dark then sanding out again).

So, my Plan A is to (a) use 1/4" durock on top of the 3/4" plywood subfloor under the 1/4" tiles inside the powder room, (b) use a narrow marble threshold installed parallel to the existing hardwood floor to transition between the hardwood and the tile.

I'm hoping someone could provide advice on the following three key issues:

(1) The finished tile and hardwood floor will be about the same height, as would the TOP of the marble threshold piece I have; but since the marble threshold is bevelled, if it sits right on the plywood subfloor the bevels would extend below the top edges of the hardwood and the tile. So I was thinking I should raise it, but if I extend the 1/4 inch durock under the marble threshold, it would seem that it would stick up too high creating a trip hazard. Can I use some type of thin-set layer directly on the plywood to bulk up under the marble threshold, or should I just accept the 1/4+" excess height of the threshold?

(2) Since I'm stuck with parallel hardwood is there some type of flexible grout I can use between the marble threshold and the wood to absorb the wood's lateral expansion/contraction? Should this grout joint be anything different than standard width?

(3) Is there some extra heavy duty grout sealer I can use on the tile since my son's aim has not really improved?

Thanks anticipatorily for any and all advice!

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Old 10-12-04, 07:55 PM
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My first choice would be to try and match the hardwood and make an oak threshold.

My second choice would be no threshold at all. Layout the tile so that you have full tile from the doorway, with the factory edge of the tile butting up to the hardwood. Nice clean transition .

I don't have a third choice for you. I hate marble thresholds. They almost never match you end up with 3 different colors right in the doorway.

Aquamix grout sealer should do the trick for you....or just use yellow grout?
Old 10-13-04, 12:26 PM
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I whole-heartedly disagree. As a restorer of old homes one of the coolest things you can do is incorporate a marble threshold between a bathroom and a living space with hardwoods. Marble thresholds are fabricated with various thicknesses and various widths with a standard bevel on both top edges. The thickness is larger than standard tiles, slates, marbles, or stones, so it's supposed to stand up a bit anyway. If your tile and hardwood is the same level, then chances are the threshold you buy will be thicker than both, so you shouldn't have to worry.

BUT - and this is a big one - it sounds like you're thinking 1" of substrate is good enough for your bathroom. A minimum is usually 1 1/4 - 1 3/8". Therefore, you would have to at least lay 1/2" tile backer in there, which means you'll have a step-up into your bathroom instead of an even transition. Otherwise you may be faced with cracked grout and tile later on.

That changes the marble threshold thing. You might have to have a special threshold made, or have an existing one ripped down to acomodate the step up into the bathroom. Use a dremel tool and a router to carve out whatever hardwood you need to set the marble in place (you might not need to), and use a modified thinset to set the threshold in place. Use a calk that matches the grout of the tile between the threshold and the hardwood to allow for expansion, and grout the joint between the tile and the threshold unless the threshold is set independent of the tile backer the tile is sitting on. If your tile backer doesn't extend into the doorway you may have to calk both sides of the threshold so expansion can happen on both sides.
Old 10-14-04, 06:16 PM
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Thanks for the advice to date!

Sincere thanks to adanac and COBALT for the very helpful replies. It's never fun to go back to the drawing board, but it helps to be doing so with such thoughtful advice!

Plan B is still evolving, but it sounds like I'd better switch to 1/2" durock to get the full 1-1/4" subfloor. Shimming the tiles and and the threshold I already have in hand up to that height, it seems like the threshold does stick up too high (about 1/2"... so a good part of the side of the threshold below the bevel is showing). So I guess I should either look for a thinner threshold or perhaps put the threshold over a separate piece of the 1/4" durock (and caulk on both sides rather than just on the hardwood side).

And aquamix grout sealer (along with a new rule that little boys must either sit or use the old upstairs bathroom) sounds like a good strategy for avoiding future damage!

Again, thanks to both adanac and COBALT for the great advice.

Old 10-14-04, 07:28 PM
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No problem, and yes it does sound like your threshold is too thick. I just bought one for a bathroom I'm working on, and it was only 1/2" thick.
Old 10-14-04, 08:05 PM
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Hardwood and ceramic tile transition

Leave the required 3/4" expansion gap for hardwood between it and ceramic of same height. Install a T-mold transition piece stained to compliment hardwood floor.
Old 06-09-11, 07:41 PM
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I agree that a marble threshold can add understated class to a room, a really nice touch and not difficult to install.
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