MDF vs. Particle Board for Shelf

[tomzarbo]

Recently I installed a few unfinished kitchen cabinets in my basement for storage and what-not. They were bargain cabinets with unfinished oak front frames and doors.

Before:


After: Please note mounted double gang wall box for hookup to shelf stereo system running two in ceiling 8" two-ways with pre-installed wire for an additional powered sub in the future.



So back to my question:
There is one shelf in each, 1/2" particle board the widest of these cabinets is 36" wide and there are two shelf pins on either side as well as one in the middle on the front of the cabinet between the two doors.
The shelves are 10.5" deep by 34.5" wide.

I want to add another shelf in each cabinet, and I want to use 1/2" particle board, but I can't find it locally so I'm wondering if MDF would sag too terribly much given that the longest span would be 18"? I would use them as the highest shelf and they wouldn't have much weight on them, probably just seldom-used stuff in plastic bins with labels.

Do you think 1/2" MDF is okay for this use? I already have enough of it as well.

I'm planning on covering them with the vinyl that PE sells for an aesthetic match.

Thanks in advance,
TomZ

[fastbike1]

No. Why don't you just get some prefinished shelves from HD or Lowes. Not too expensive and they won't sag or swell like the mdf.

[Dave_W]

Tom,
You'll be OK with either one. 3/4 would be better and PB would be better than MDF, but for your application I think your good with whatever you use.

Also, check out the Sagulator. Shows shelf deflection based on span, load, and material. MDF, PB, and OSB are at the bottom of the pull down list.

Recently I installed a few unfinished kitchen cabinets in my basement for storage and what-not. They were bargain cabinets with unfinished oak front frames and doors.

Before:


After: Please note mounted double gang wall box for hookup to shelf stereo system running two in ceiling 8" two-ways with pre-installed wire for an additional powered sub in the future.



So back to my question:
There is one shelf in each, 1/2" particle board the widest of these cabinets is 36" wide and there are two shelf pins on either side as well as one in the middle on the front of the cabinet between the two doors.
The shelves are 10.5" deep by 34.5" wide.

I want to add another shelf in each cabinet, and I want to use 1/2" particle board, but I can't find it locally so I'm wondering if MDF would sag too terribly much given that the longest span would be 18"? I would use them as the highest shelf and they wouldn't have much weight on them, probably just seldom-used stuff in plastic bins with labels.

Do you think 1/2" MDF is okay for this use? I already have enough of it as well.

I'm planning on covering them with the vinyl that PE sells for an aesthetic match.

Thanks in advance,
TomZ

[timk]

You'll get no noticeable sag with PB or MDF on an 18" span even if you load them up.

We don't worry about sag in spans under 30".

www.timkulincabinetry.com

[tomzarbo]

No. Why don't you just get some prefinished shelves from HD or Lowes. Not too expensive and they won't sag or swell like the mdf.

I don't think I'd be able to find the right dimensions. My shelves are 10.5", and I think most commercial shelves are 12"? I'd probably have to cut them anyway.

Tom,
You'll be OK with either one. 3/4 would be better and PB would be better than MDF, but for your application I think your good with whatever you use.

Also, check out the Sagulator. Shows shelf deflection based on span, load, and material. MDF, PB, and OSB are at the bottom of the pull down list.

Hey Dave, thanks for the link to the website; bookmarked... that's a cool one! I put in some educated guesses on weight and as you said, it looks like it will hold up okay.

You'll get no noticeable sag with PB or MDF on an 18" span even if you load them up.

We don't worry about sag in spans under 30".

www.timkulincabinetry.com

Thanks, Tim. I shall not worry either! If a cabinet maker says it's okay, then it's okay!

Now I just gotta get my table saw dialed in so I can start cutting!

TomZ

[LouC]

If these are going to store any kind of liquids, it may be worth going to shop grade 1/2" plywood. I did some mdf shelves. Sag was never a problem, but spilling some water base finish delaminated the shelves quickly. MDF or Particleboard should hold the weight, but you might slather them with some kind of clear coat.

[Woodfiend]

Tim : he is talking about using 1/2 inch material. I wouldn't recommend 1/2 inch material for any shelving over 16 inch wide. Especially not past 30 inches. Anything close to 36 should be a solid 1 inch thick. IMHO As a cabinet/trim guy myself

Ok I did some more research....... Looking at shelf spans in the AWI Quality Standards book a 12" wide 3/4" melamine coated medium density particalboard spanning 30" will take a load of 117 lbs to deflect 1/4". Other materials are as follows:
1" melamine " " " " 277 lbs.
3/4" particalboard covered 2 sides 1 edge with high grade plastic lam. 350 lbs.
3/4" particalboard w/ 3/4" x 1-1/2" solid drop edge 435 lbs.
3/4" maple or red oak lumber 534 lbs.

I let my membership lapse with the AWI (the costs are too much and it reminds me too much of THX certification ). But they still have some useful info.

[Woodfiend]

Oh just saw that you have middle or center shelf supports........ ok you are alright then. I would still use 3/4 though.

[tomzarbo]

I just looked at the shelves in my kitchen loaded down with heavy dinner plates and such and noticed that they are only 1/2".

So I guess I'll be okay, it shouldn't sag much if any... I'm not planning on having a bunch of heavy stuff up there anyway and what will be up there (top shelf) will be in bins, which carry more weight on the edges than loose stuff would.

I have plastic shelving on the other side of the basement for paints and liquids, this will be more for bits, blades, some screws, hardware, stuff like that.

The cabinets came with only one shelf per each cabinet, which is fine when you're putting 10 plates or bowls in there...you need space to move stuff around, but it's a bit of wasted space when dealing with smaller stuff.

I have to say that I really like these cabinets, for the money I can't beat them.

http://www.lowes.com/ProductDisplay?...llow&cId=PDIO1

I have three base units of this same design in my hobby room with a counter top to make a soldering/electronics area for building crossovers, etc. and I'm really happy with them.

Thanks for the advise and help everyone.

TomZ