Fill with grout...or something else?

[Capt W]

I'm doing a lot of house remodeling and just came across what I think is an unusual shortcut taken by the home builder 20+ years ago. In pulling some hallway baseboards in order to replace them, I noticed they must have been installed before the tile floor was installed. In other words, the baseboards are largely resting on the house's slab, followed by tile that meets the baseboard and grouted in at the joint. The baseboards are thus sunken about 3/8-inch lower than the tile's surface. Not sure if this was SOP in 2003, but seems to me the floors should have come first, followed by the baseboards. When I install LVP flooring, I run the planks to within 1/2-inch of the walls, allowing the baseboards to sit on the new flooring instead of sitting on the slab.

Anyway, before I reinstall new baseboards, I want to fill the large gaps. As you can see, the gaps are almost 3/4-inch when viewed from above, so most - if not all - new baseboards would immediately drop down to the slab, requiring either new grout or copious amounts of caulk fill the remaining gap. Also not sure I like the idea of wood or MDF baseboards just sitting on the slab...

My thought is to use 3/4-inch backer rod and fill the entire gap with new grout. After it dries, this should give me a stable (and hopefully level) surface. I could then install the new baseboard resting on top of this newly filled gap and would nullify the need for further filling at floor level.

I haven't done any tile or grout work in my life, so not certain this is the best solution. Am I on the right track, or is there something better?

 

[DBMaster]

If you don't object to the looks, mount the baseboards with the bottom at the level of the top of the tile and then attach quarter rounds to the bottom of the baseboards. A grout joint that wide would likely end up with a lot of cracks down the road.

 

[Capt W]

Should have mentioned that...the last homeowner did the quarter-round addition in all four bedrooms and we think it looks terrible (and collects more gunk at the seam). I refinished one of these setups in a spare bedroom because the previous owner installed LVP but didn't pull the existing baseboards for that job. He had to use quarter-round to cover the gap. Shortcut-city.

We want to install very smooth 3-inch high baseboards or something similarly minimalist.

Good point on the grout fragility. Wondering if pourable leveling compound might be more durable to fill such gaps.

 

[spasm3]

Are you putting down new floor over the tile?

 

[Capt W]

Nope...just replacing baseboards

 

[tnt_motorsports]

if you don't want to replace the flooring, you might want to consider a custom baseboard. Imagine something like a crown molding style of baseboard. This will give you the added thickness you need. IMO, 3/4" is significant ground to cover with conventional baseboard. If you have or can rent a router you can make your own baseboards. My grandfather did this years ago when he helped finish my mother's basement. He made all the trim, but in the early 90's it was more of a make versus buy era IMO.

 

[spasm3]

Could you use this for a base board, if it's not a long run? It's 1 inch thick on one side.

Fill the floor gap if you like with Durham's rock hard putty.

https://www.homedepot.com/pep/RESO-...jatBtgd64lfHYGzMHUUaAhJmEALw_wcB&gclsrc=aw.ds

https://www.homedepot.com/p/Durham-s-Rock-Hard-DU-1-1-lbs-Water-Putty-1-CAN/100184116

 

[Cujet]

I'm guessing the room had carpet before the tile as my home did. My baseboard trim goes down to the slab, is 23 years old and the tile is prob 18-20 years old. In the end, we put the tile close to the baseboard and grout in the gap between. It has held up well for being so old. There is a little shrinkage and separation here and there. But really still looks just fine.

 

[Capt W]

Trying to get away from grooved/ornate baseboards. Really want something thinner and smooth that's much easier to keep clean. I like Cujet's setup. I'll probably just install taller baseboard and grout it in at the bottom for a clean look.