Hi All

A client has asked me to quote on sliding doors between a bathroom and bedroom. It'll be hanging like a barn door, about 3 by 7 feet by 1 3/4 thick - just a slab.

MDF is flat, heavy and doesn't take hits well.

Wood is lighter but much more labor and might (will?) warp.

Several hundred of them.

Opinions please and thank you.

Buy them from a door manufacturer, hollow core.

By my calculation a solid MDF 3' X 7' X 1-3/4" door would weigh close to 130 pounds. My personal feeling is that is too much for a sliding door in that application. Bathroom doors are used by everyone, young & old, and it may be a challenge for a six-year-old (or 80 year old) to open or close that door.

I understand your concern over a wood door warping because of the moisture, but bathroom doors are typically in the open position when not in use. I have never had anything other than a wood doors in my home, including the bathrooms and never had an issue.

If good hardware is used weight will not be an issue. If cheap hardware is used the lightest doors will still not move easily. I built a set of 4 pocket doors for a client a couple years ago. 3 went into openings where the box store hardware was already installed by the contractor. The 4th door, which was solid Walnut 2-1/4" thick 38" or so wide and 8' tall with glass panels, went onto a track I installed. The client called wanting to know why the 3 smaller doors were so hard to open and the large door could be moved with one finger. I had to explain to him why the smaller doors wouldn't slide well and how much work was involved replacing that crappy hardware while trying not to throw the builder under the bus.

So the question you need an answer to is what is your client looking for? Personally I'd go with the inexpensive mdf slab and the better hardware.

good luck,
JeffD

Solid wood, properly dried and selected and joined, has been the material of choice on this planet for over 2,000 years. No reason to reinvent that wheel, in my opinion. Jeff is correct on hardware.

If you are unsure with using wood, hire a professional door maker. In 25 years and 4,000 doors, I have had 3 warp enough to be replaced.

Wall mounted barn doors are popular now, but are typically not successful as bathroom doors since they cannot be locked, and leave generous gaps at the perimeter. Also, few designers take into consideration the loss of opening width that surface mounted pulls require - usually 5-6".

I would agree with David R. partially. Solid wood is great, but I too have made many doors of the years. I have found that a combination of wood and engineered products work best. I pulled a pair of doors out of a church that were approximately 140 years old locally. They were built very similar to my preferred building method of stave core. Trust me if those fellows and gals years ago had access to our technology and tooling as well as the many choices of engineered products they would have taken advantage of them. High end architectural stuff will always be solid wood but MDF and other products allows for some important valued engineering. I would imagine the life expectancy of the doors you are building is no longer than 10-15 years in a commercial setting. MDF is fine; we all do this for money right???? It’s not a short cut or cheap way it’s what they can afford, offer them solid wood and they will fall over from the price.