Well after reading this...it scares me. I've been in the industry for over 30 years, and there are pros for both methods as well as cons. Choose wisely as it can affect your future situations. First, one post talks about setting doors in on top of floors to eliminate cutting around casing. This is WRONG on many levels. First if the door is exterior it has to set directly on the main floor, either concrete or subfloor. If interior use a piece of 1/2 inch drywall for doors and for the base to leave a gap. If your doors already go all the way down just use a jamb saw to trim the casing and there will be no cut lines around them. This is why they make the saw. Also, think, if you put your doors, trim, or cabinets on top of a floor and then there is a problem with your floor, you have to remove it all. This adds risk and cost. But, if you use shoe mold or quarter round, then you never affect anything but that part. Imaging breaking $5000 worth of granite because you put flooring under your cabinets and couldn't get it out without removing them. Yes you could cut around them but what if water was involved? Do you want water there underneath where it can mold?. Shoe is cheap, quick and easy. Minimal added expense to protect the possibilities. You can remove flooring without affecting surface materials and vice versa. Sure, flooring installers like to do floor first because it's easier and faster with less cutting. But they don't pa for the problems that arise in the future. Think hard about saving a very small amount of money in the scheme of your project. I will NEVER do a job where the flooring is underneath, I'd rather just walk away and let someone else absorb the risk.

I'll resurrect an old thread to provide perspective from 12 years later. The house I'm referring to is located in north west Mississippi so it does get moderately humid here - inside is usually 50%-60% RH during the summer. I built our house 12 years ago and used 5 1/4" MDF baseboard identical in profile to what you'd find at lowes/homedepot. I did not have them paint all sides (probably should have). In the wet areas near the shower and tubs, I should have used wood - I'm not sure if painting/priming all sides would have made any difference. When water gets behind or under MDF baseboards, they will eventually blister, bubble, and crumble. The base 'cap' was integrated (very common) on ours and seems to be less tolerant of bumps and bruises than I'd expect wood to be. Our house is high traffic with lots of kids and there is one narrow hallway where several pieces of the "ridge" on the base cap have chipped off. The painters I used were good not great. They used a Sherwin Williams product for the trim which I believe is supposed to be a 'fast coat' and from what I can tell, they did one coat. I repainted all the baseboards in prep for selling with the ProClassic and I can tell the difference - they look much better. The painters also did a terrible job of sanding the nail holes - lots of tiny bumps where the nails are. Had I known/seen it, I would have made them re-do it. That said.. after 12 years, we are relocating and it wasn't hard to touch things up. I wouldn't hesitate to use MDF again, but I learned a few lessons: - Allow MDF to acclimate to the room (they did this on mine) - Prime the back/sides that are not already primed - Glue all outside mitered edges - Proper touch up on filling nail holes - Sand well before painting - Use a high quality finish and take your time doing it - Use wood in areas prone to heavy moisture like bathrooms.

I don't know that is is necessary if you catch a stud every 16". Also there is probably a plate that you can nail just above floor level as well. I assume you are you planning on caulking (paintable caulk preferably) the top when you get it installed. That will be enough to hold it in place. Just my .02 Oh yea, paint the trim prior to install, then all you have to do is fill the holes and touch up. Good luck

Little bit of an observation It is getting very hard for tile pros to even bother commenting on these forums, everyone is now a tile expert repeating things they learned on the web and getting it wrong more ofthen than not. Im not on the legal forum giving legal advice nor am i much commenting on designers threads. That is a general observation and the reason less and less actual tile pros are commenting here. And thats not directly intended to slam Patricia, nor any one person I know she usualy has good advice. I suppose the only undebateable way to answer here is to copy actual industry standards. @ OP. No caulking either you need a 1/4" expansion joint at the entire permiter of the assembly COVERED over by base board PER TCNA specs. In regards to the "Whole house comment" here is the answer directly from the TCNA updates to the 2017 handbook. Why are movement joints needed? Recognizing that tile is a facade, movement joints are needed to eliminate stresses that can occur between the substrate and the tile due to differing amounts of expansion and contraction. Where should movement joints be placed? The TCNA Handbook recommends allowing for expansion and contraction in every tile installation. In small rooms, a gap at the perimeter of the room (often hidden by baseboard or shoe molding) is sufficient. For larger areas, the movement joints will be visible. We cannot specify the exact location nor frequency of movement joints as there are many site related conditions that must be addressed; however, we do offer guidelines in Detail EJ171 in the TCNA Handbook. It is especially important to note for interior installations, movement joints are placed more frequently when moisture or direct sunlight is expected. For exterior installations, the range of temperature from summer highs to winter lows must be considered. Updates and more: Even though the TCNA Handbook is published every year, the majority of the changes are made in odd numbered years. There are many changes to the 2017 Handbook; here is a summary of the expanded and clarified sections. EJ171 Some of the most important changes are found in EJ171, concerning the location and installation of movement joints in the tiled assembly. These changes were made to help clarify the guidelines to architects, engineers and installers. First, the location of a movement joint is no longer confined to a range; rather, proper placement is defined with a maximum spacing and no minimum spacing. Interior movement joints shall be placed no more than 25'apart in both directions. Movement joints in exterior installations, interiors exposed to direct sunlight and above-ground tile installations shall be spaced NO more than 12' apart in both directions.