Seeking Opinions on Plywood Closet Doors
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I need to come up with some sliding closet doors, two of which are non-standard size (~65″). This would probably mean a custom build, and the prices for even the standard size, crummy MDF core doors are already ridiculous. The obvious alternative is to get a hardware kit and slab doors. I found some nice soft open/soft close hardware kits and I note that the minimum door thickness is 3/4″. So immediately I thought of using a hardwood veneer plywood instead of an actual door. Price should be similar to a hollow core door, and I think it would look nicer. Is this a good idea, or a hare brained one?
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Replies
Plain plywood tends to warp, even the best grades, unless it is braced.
You'd probably have more luck with two pieces of quarter inch luaun with a 1x2 frame between them.
Making your own panels isn't a bad idea, but keep in mind that 1x material can warp too. There are other materials less prone to warping. If you have the ability to rip some plywood strips with decent accuracy/consistency you can glue thin strips together to make pretty rigid stringers from the plywood. I built an 8' long desk using this technique and you can drive a car over it without it flexing.
I've made a lot of doors on the large side from 3/4" MDF, or MDX. They are heavy but less prone to warping than veneer-core plywood. If you like the wood look, you can get veneer-faced MDF and MDX, or you can veneer your own. But they can still warp in some cases; a torsion box as DCContrarian describes would likely be the most stable option, and would weigh a lot less. But they are more work than simply cutting MDF to size. (MDX is water-resistant and I believe more stable and easier to finish the edges than MDF.)
Trevor,
You might want to ask a sign company about MDO plywood used for outdoor signage. It means Medium Density Overlay. I have found the random pieces I have used over the years to be much flatter and better behaved than ordinary plywood.
Two other alternative plywood products you might look into are phenolic faced forms plywood which might be available in big enough sheets. Though very spendy, they will stay flat. I use scraps for jig faces as do many commercial vendors. The plywood body is multi-ply like Apple Ply a brand name I think for a 13 ply 3/4" sheet good.
ApplePly's sell point I believe, is that every layer is plugged so you never get voids at the edges. Old Playskool products for schools used something like it. The brand name is spendy but again it behaves better than regular ply. I picked up several sheets of Russian sourced multiply one year at the orange box store and despite two sheets being stored in my garage, they appear to be flat after 6 years. Someday they will become cabinet carcasses.
A real left field idea if lightness is the issue would be RhinoBoard a Foamcore product used a lot in exhibition displays. It comes in various thicknesses and is brutally strong stuff. It does have the downside of exposed foam at the edges, but T-strip inserts would make a quick cap.
Thanks for the ideas, all improvements over my idea. However, the more spendthrift and/or labour intensive it gets to do it, the more it makes sense to just buy some "regular" doors to mount to the hardware. I'm not concerned about how heavy they are, in fact I'd prefer they have some good heft.
Trevor,
Back again with a question and maybe advice. Are these short doors like in a Cape Cod upstairs bedroom, that need to be 65" tall. I can't imagine 65" wide doors being called for.
Cutting down plain hollow core doors would be pretty easy if you are willing to fit in a piece of wood to keep the skins stable on the cut end. I would cut the bottom and keep the top factory fresh for the hardware. I have done it a number of times. The key to getting a nice edge is to deeply score the skins with a utility knife before going at it with a circular saw. Also, cut with the face side down just in case you wander off line. The teeth will be pulling into the skin on the good side and not causing splintering to go up past the cut line.
Be warned that some MDF doors are overlays on very coarse particle board and some are more like very thick skinned hollow core doors. Similar patches for the cut end, though the MDF is more forgiving of the saw teeth presentation. I would still score on both sides to preserve the primed finish.
The closets are standard height. The 65" width is total, so each door would be around 33" (there needs to be a bit of overlap for bypass doors).
At my Home Depot hollow core doors start around $40 and a sheet of birch plywood is $59.
Trevor,
If the imbalance of using 34" doors (leaving one side with 31" viewed) is not acceptable, you might get away with trimming them 1/2" on both sides to reduce the match to 33 front track, 32 back track.
The hollow core side stiles are pretty thin above and below the blocks put in to accommodate door knobs. The ones I have cut open are barely 5/8". The filler in many low end doors is corrugated cardboard strips. The MDF doors are a little bit more forgiving, but still skimpy on how much real wood is available for trimming. The heavier MDF doors might have as much as 3/4" solid stock capping the core material down both sides. This is due to having need for screw-able material that will take the weight. Maybe you can contact the manufacturers for extra assurance that trimming the sides won't leave you with core showing. They will of course disavow such a tactic and say the warranty would be voided.
One other cheat I had to do in my own renovations to fit a balky bi-fold was to replace the side jamb stock with half inch stock. (these days more like 7/16") Depending on how much shimming was done, you might find there is an extra inch or so to be squeezed out of the rough opening. Hopefully, the trim carpenter set the top piece first at full width so you don't get a gap while skinny-ing down the side pieces. You will need to redo the top trim.
Last thing to note, like plywood, doors are no longer truly the width ordered. My 30" pre-hungs are all a hair under 29 3/4", so I suspect 34" ordered would show up 33 3/4". At that size you would only need to skim off 3/8" each side. Years ago, before pre-hung dominated the market, doors were the size stated and you built jambs accordingly. Closet door panels are not likely to made to full size due to production constraints, but be sure to ask.
I'm going to use either french doors, or a shaker style, both of which have solid cores. No trim is installed yet (or jambs for the closets either, for that matter).
The pre-hungs I installed for the rooms in my house are 1/16" under nominal. The french door I used for a pocket door was bang on to size.
Trevor,
You must be buying better grade doors ;) My pocket doors are a fat 1/4" under size like the pre-hung. If you still are looking at rough framing for the closets, why not pad out the opening to make it 63" - 63 1/2" wide and use two 32" slabs? No one but you will know the opening shrank.
I think the biggest opening is 67". If I try to shrink bit down 3.5-4", that would probably mean fixing a gap in the drywall that the trim won't cover. That's more offputting to me than trimming the doors, but I will certainly measure and see if it can be done without drywall work.
Unless you have a really stupid house like mine, with 1 1/2 inch trim, I think the trim will cover.
Honestly the tiny amount of sheetrock mud work involved would be my preference to messing with doors.
I'm going to dredge this up again. I haven't been able to let go of the idea. What about using particle board instead of MDF? That seems like it would be more durable and just as warp resistant. I could get a 1/4" birch ply to face it, or I could get 3/4" particle core ply and put trim around the edges. That would be somewhere around $450 versus upwards of $1600 for mediocre quality pine or acacia veneer slab doors.
Trevor,
Some years ago I built two doors using the techniques in this FHB article. It a pretty low skilled way that yields a nice result.
https://www.finehomebuilding.com/2005/01/01/custom-doors-done-easy
Trevor,
Particle board can be dicey depending on the fineness of the particles and the glue used. I had assorted pieces kicking around the shop that seem fine after many years. The really coarse stuff appeared to be almost 20% glue. Those pieces were originally cutoffs of paintable shelving stock that came with a molded bullnose. They were very stiff. I don't recall ever seeing full sheets of it. Coarse sheet metal screws worked well when attaching brackets.
Other pieces had a finer texture like a fine cork board. There was much less apparent glue bonding the bits. This variety would take a bend if left leaning against a wall. Screws do not hold well in it. The thin version of this is often seen as back panels on low grade cabinets. I have also seen the same grade wrapped with vinyl used for a very weak shelving stock.
MDO or medium density overlay stock is frequently used by sign shops. It is quite stiff and paints beautifully if prepped right. Screws do okay in it. 1/2" would not be terribly heavy. Veneering it might be possible though the surface finish is very smooth and almost slick.
MDF comes in a variety of densities with the hardest panels being both very heavy and dead flat. I acquired several sheets of unfaced and several sheets of veneer clad from a bankrupt shop that specialized in banks and lawyers offices. 4x8 sheets are north of 70 lbs if my back is correct.
If you can locate a shop near you that veneers MDF to panel fancy offices, you might find it cost palatable to have them veneer the good faces with your favorite wood. The backs would need to have a secondary wood choice to balance the veneer face or overtime the panel will bow. I am sure they could edge it in a matching wood.
You could try to apply the 1/4" birch ply to a particle board, but the gluing and pressing required would be very tricky without equipment and experience. Contact cement is not cheap and one wrong move will reward you with a skewed panel or worse a forever air bubble.
Are you sure that reducing the opening isn't ultimately less bother?
Trevor,
Not directly related to your question, and you may already know about these processes/systems. For a durable finish on MDF, there may be a powder coating company in your area that offers this service. Another option that I find intriguing is furniture-grade Marmoleum as a veneer.
Just providing a follow-up to this. Being the stubborn person I am, I went ahead and made the closet doors out of plywood. I have to say, I have no regrets. Are they perfectly flat? No. Is it noticeable? Also no, and it saved me around $1000. I made the first set out of 3/4" plywood. I found that a bit unwieldy, so for the remaining three sets I went with 1/2" plywood and framed it with 1" solid wood. I haven't trimmed around the opening yet, but here's what one looks like. Soft open and close hardware makes these the most user friendly closet doors I've encountered.
Hello - working on the same concept
is the 1" wood trim to stabilize? Do I need to use the trim?
and may I ask what size track you used for 1/2 inch doors? Will a min 3/4 still work? TY
The 1" trim serves two purposes. 1) It covers the exposed edge of the plywood for better aesthetics, and helps to visually cover the gap between the doors when closed. 2) For the half inch plywood doors, it provides the structural attachment for the hangers on the top. The top piece wasn't necessary for the doors I made of 3/4" plywood. The track I used specified a minimum door thickness of 1", but I found 3/4" was enough. All the hardware I used was Johnson Hardware (100 series soft close).
I'd say some kind of wider trim is necessary to get acceptable results.
Looks great--thanks for the follow-up.
Thank you so much! so nice to see other creative minds making it work!