Caulk is by far the better choice. Reasons are:

Caulk allows for movement, grout does not.

Caulk is much more easily removed. Grout is hard.

Caulk is more easily applied in this case. Grout would be very messy and difficult.

Thanks -- I just wanted to be sure that the caulk could be removed without damaging the wall, in case I replace the tile.

Any suggestions on what type of caulk? The gap will be as wide as 1" in places.

"The gap will be as wide as 1" in places. "

What? You shouldn't grout or caulk up to the raw wall. Reinstall the baseboard and quarter round over the tile. Then, caulk the joint between the 2 surfaces.

No reason to raise the baseboard now - just install some quarter round over the gap. As for the air gaps, you might just apply some caulk under the baseboard in that spot before installing new quarter round. BTW, you should also check the exterior for gaps and seal them up (with caulk, foam, etc.)

I need to raise the baseboard for aesthetic reasons. It has some detail, and the quarter round needs to attach to the bottom of the baseboard which is flat.

So, I don't need to fill the gap? I guess caulking where the quarter round meets the tile would prevent water from getting in there -- sometimes I saturate the floor pretty throughly to clean.

Thanks for the suggestion about sealing interior and exterior gaps for air leaks. The patio is outside that north wall, and there are spaces between the patio and brick exterior.

Grouting under baseboards would do nothing to make the area watertight. If the caulk doesn't stop the water, it will be flowing under the baseboard either way.

Not sure what you mean about the bottom of the baseboard. Just to be clear, shoe molding and/or quarter round doesn't go under the baseboard, it goes up against it. Once installed, caulk it to seal out the water.

Alternatively, you could replace the baseboard with tile, then grout or caulk.

Thanks to everyone for the excellent advice. It seems obvious now that you've explained it, but I would have wasted a lot of time (and no doubt aggravation) doing something unnecessary. I came here seeking advice on how to do a task, only to learn that I don't need to do it at all -- doesn't get any better than that!

homebound -- I should have been more clear -- the front of the baseboard has detail, so only the lower portion is flat so as to accommodate the shoe molding.

You guys are great, and I really appreciate this forum. I'm sure I'll be back!

Thanks, paintguy, for discouraging caulk between the shoe molding and tile. It didn't occur to me that it would attract dirt.

I'm going to refinish the baseboards. They are mahogany and original to the 1964 house. I've done that in another room, and they look nicer and are much easier to keep clean with 3 coats of spar urethane. I wasn't planning to do that, but while I'm at it...(the story of my life).

This question may belong on another forum, but I'll ask here. When I refinished baseboards before, I stripped, stained, applied 2 coats of spar urethane and lightly sanded before installing the baseboards and shoe molding. After installation, I filled the nail holes and applied a final coat of urethane in place. This area is much larger, and I don't think I can do the final coat after installation. I was planning on completely refinishing the baseboards and shoe molding, installing it, filling the nail holes, caulking above the baseboards and then painting the walls. Does this sound right? I use an oil base color putty to fill the nail holes. It should have a finish coat, but I can't imagine trying to put a final coat of urethane on the installed baseboards in this large of an area.

Yep, it sounds right, though I'm not a big fan of caulking stained trim to the wall, I know there are plenty of people that do that. Ideally, we want to apply the finish over the putty, but this is less important for trim that is not at eye level. The putty will eventually dry up and fall out of the holes, but this could take years to happen. If you plan on filling the holes and not applying a poly after that, I would carry around a clean rag to wipe off any smear marks that the putty may leave behind.

Do you mean that if the trim is stained, it isn't caulked at all, or that it is preferably caulked to the wall before staining?

I might try to just dot some urethane over the putty, but I've never done touch-up work with urethane. I was pleased with the final coat of urethane applied in place, but I did that in a small room. It required a steady hand mostly lying on my stomach, and this is a big area.

I really appreciate your input.

Yes, stained trim generally does not get caulked at all. Stain doesn't penetrate caulk so caulking prior to staining would really create a problem. If you really wanted to caulk that gap on top of the baseboard, the only way to do it would be to caulk it after the baseboard is finished, but before you paint the walls.

Just another idea for your consideration. Stain, but don't prefinish the molding. Install the baseboard, run a bead of clear silicone caulk and apply the shoe molding, making sure you clean off any squeez out as you go. Tape off the molding and apply some light weight joint compound where there are gaps between the wall and the baseboard. Sand and vacuum then smooth with a damp spounge. Wait a day and then undercoat and paint the walls and filled in gaps. After everything dries, remove the tape and paper covering your molding and tape off your floor. Get a edge guide to hold against the top of your baseboard so you don't paint the wall. Now, you can finish the molding without getting the finish on the wall or floor. You should not use marine varnish because it doesn't completely dry. If I did not have a spray gun I would buy enough spray cans of finish to do the job. If you use n/c lacquer you don't have to sand between coats but make sure all your pilot lights are out and the room is well ventilated. If you use waterbourn finish you will have to scuff sand between coats. Or you can use a brush but spray will usually give you a better finish. Dont use steel wool with a waterbased finish for your final rub out unless the finish has dried for several days. Remove the tape, vacuum and your done.

someone2010 -- you make it sound easy, but as an amateur, I'm afraid I could really screw that up. I've never sprayed on finish, and I doubt I could do it evenly.

Would the bead of clear silicone caulk fill the gap between the baseboard and shoe molding?

Assuming I could muster the courage, what is n/c lacquer? It's the sanding between coats that makes me want to prefinish before installation.

I had no idea marine vanish was a bad idea. I've used it to refinish my kitchen cabinets and all of the woodwork (cabinets, trim and baseboards) in a bathroom and it seems satisfactory. I don't worry about using water to clean it, and the finish seems hard and smooth.

Maybe I could do all but the last step, and hire someone to spray the finish on the baseboards and shoe molding.

If it works for you, that's good enough for me. What brand do you use? Is it water cleanup or paint thinner cleanup? Most marine varnish says for exterior. If you call the phone number on the can, they can tell you if it is correct for interior but like I said, if you've had success with it then that's what to do. You have to like it. In any case, nitro cellouse lacquer has lacquer thinner as the carrier. There is also a waterborne lacquer. For your purpose I would suggest the waterborne type. It is more impervious to water after it dries. Some water based finishes require sanding between coats and some don't, but make sure you follow the instructions on the can concerning what stain to use and surface prep. For sanding between coats you could 220 sand paper or the pads put out by 3M (they are like kitchen scratch pads and come in different grits). You just need a light sanding to get purchase for your next coat or lightly sand out runs. If you use a tack rag, use one made for waterbase finishes. If you want to brush on the waterborne finish I suggest General Finishes products. They are expensive but are more user friendly than products like Varathane. You can go to their site on the web and get a lot of information. If you want to use aerosol cans, I suggest Deft waterborne spray. If you choose one of these methods, there is a cardinal rule you should follow. Don't pratice on the piece you are refinishing. Get as large of a piece of the type of wood you are refinishing as you can and pratice on that. There is a learning curve but not one you can't surmount. The hardest part for me was always taping off. You want to tape in a sequence so you are not applying tape over a newly painted surface. I said to stain before installing so if you don't totally get off all the clear caulk, it won't show up as a light spot on the finished molding. If you decide to use areosol, then just get one can and pratice on your pratice board. If you decide to hire someone to spray, have them use Hydrocote Resisthane Plus, and tell them not to thin it. I don't think you need to hire someone. If you like brushing then take your time and use the General Finishes products or use what you used on your other molding. Make sure you locate and mark your studs and predrill the nail holes in both moldings with a drill bit a little smaller than your nails diameter so you don't split the wood.

The marine varnish is certainly overkill for interior baseboards, but you should use what you are happy with. Exterior products are mainly not recommended for interior use because they just stink and have UV inhibitors that are not needed inside. I would just use some oil based poly, brushed on after installation...perhaps I would do the first coats on horses before install and then just the final coat of poly after. The spray cans of anything are thinned way down so that they can be sprayed so it would take multiple coats to achieve a mil thickness similar to what you would get with one brushed coat.

In the past, I've finished my cabinets, trim and baseboards with Minwax indoor/outdoor helmsman spar urethane. I've brushed on 3 coats (lightly sanding between) and I've always been happy wth it. It looks good and is very durable.

However, I'm always receptive to a better way of doing things.

I have installed the baseboards after applying stain and two coats of finish and lightly sanding. After installation, I filled the nail holes and applied the final coat.

I don't claim to really know what I'm doing. That's why I'm here. I'm not at all confident in my ability to spray on a finish, and it would probably be tough to hire someone to take on a job this small. If multiple coats are required, the clean-up would probably be more hassle to a professional than the application itself.

You have a lot of advice here. You can pick through it and try what you think would be helpful to you. My advice to you would be to try the General Finishes waterborne products. You can go to their web site and look at what they have, then call them and ask then about your particular situation. They have people who will help and they also make a marine finish. Their finishes you would brush on because they don't make an aerosol. They also make oil based finishes. For brush on, I think they are the best and well worth a try. But like paintguy said, if you have found a product that works for you then do it that way. Let us know either way.

"Caulking between shoe moulding and tile is not something that is normally done."

It beats having black water get into the walls from a simple toilet overflow.

I use a clear acrylic type.
It goes on slightly purple but turns clear as it sets up.

You do not need a bead of caulk, so after putting it down push as much as you can under the trim and wipe away any that remains onthe trim or floor.

I thought of the toilet overflowing thing, which is why I would caulk the baseboard to the floor before putting shoe down....water would get under the shoe, but not into the walls. I suppose if you could caulk under the shoe, but not have too much visible outside of the shoe and on the floor, that would be a good option. But, I know that homeowners, DIY'ers and most carpenters are horrible caulkers which is why I always lean towards telling them to apply the caulk in a place where nobody would ever see.

Hi everyone. Quandary said she uses a lot of water to clean her floors so if it were me I would caulk both places and wipe off the excess. That's why I would stain the molding and not use one coat of finish first in case the tape pulled off the finish. It's easier to repair stain if need be than repair the finish, but if some caulk gets deep into the grain and she can't get it out, then it won't show because it's prestained. The taping sequence I gave is so she won't be taping over fresh paint. And predrilling of the nails is real important because she doesn't have a nail gun. I recommended the waterbased finish because it is more impervious to water after it dries than an oil based finish. I'm retired, otherwise I could never spend all this time on the computor. Now, every day is Saturday. For real, sometimes I wonder how I ever had time to work.