Dumb MDF Shelf Question (yes, I've read the others!)

[redsnapper]

Hi All,

Little advice, please, as it's my first time working with MDF!
I'm putting up some alcove shelves with a span of 1610mm. The shelves are standard (UK) MDF: 225 x 22mm.
The ends and middle of the shelves will sit on strips of 25 x 28mm wooden batten.

My question is: do you think there's a chance the front edge of the shelves (i.e. the edge facing into the room) will sag over that length? Or will the fact that the back of the shelf is sitting on wooden batten give it enough rigidity?

I expect it'll be carrying about 15kg across its length.

Many thanks all.

 

[freddiemercurystwin]

No it should be fine (or unnoticeable), you can check it here: https://woodbin.com/calcs/sagulator/

 

[redsnapper]

Thanks @freddiemercurystwin. The sagulator says the sag will be excessive (pic attached), but it doesn't account for the fact that the back edge of the shelf will be supported...

 

[freddiemercurystwin]

No you've imputed the wrong loading, which should be 3 kg per foot not 15kg.

 

[redsnapper]

I put in 15kg total, not 15kg per foot.
Looks like you've put in 3kg total, too.
I'm assuming the right hand checkbox is for 'total' but they couldn't fit the wording on one line?