Bookcase project advice.

[Markymark]

Hi

I am wanting to make a built in bookcase on the backwall of our living room. It will be surrounding french doors.

I am wanting to make it out of 8 x 4 sheets of oak veneered Mdf. 18mm for the carcass and 26mm for the shelves which will span 1.1 - 1.3 m.

I have drawn a plan and will upload it soon. I have chosen to edge the veneered mdf with kiln dried oak or some similar hardwood cut at 18/26mm and 5mm thick.

My only concern is sagging over time. This is why I chose 26mm MDF for the shelves. I was thinkining of installing a support under each shelf front making the shelves look much thicker but adding rigidity.

I would love to hear any ideas.

 

[RogerP]

I had a similar problem some while ago with some shelves sagging over a long span (someone else's build).

I routed a 15mm wide x 5mm deep groove along the edges and inserted and screwed in a mild steel flat strip - covered up with oak lipping.

Over the top? Probably, but the darned things never sagged again.

 

[mseries]

The bookshelves here at work are 25mm, about 1000mm long with a solid wood (beech maybe) lipping about 25mm deep. I think the read edge is screwed from the back too. No sagging.

 

[Argus]

.

I've done that sort of thing in the past and whilst I detest MDF, for a large acreage of shelves, it may be the only economic solution. But, it has no lateral strength to speak of. 25mm ply is stronger, but if unsupported, it too will sag in time. Books are heavy!

Personally, I would limit each shelf span to about 30 inches and you will need to brace the shelf section with a matching batten end-on, rebated so that it hides the cut edges of the MDF. I would also beef up the edge batten thickness to about an inch to give you strength.
If you insert battens back and front it will also even out the stress across the shelf.

I would suggest that, as you have the front batten looking downwards, the rear one should look upwards to act as a rear stop for the books.

Also, because there is a door, I presume that it is an external wall; if so, there will be a temperature gradient between the room, an insulating layer of books and the thermal mass of the masonry. Consider a ventilation space at the back of the shelves, open top and bottom, to avoid accumulative damp.

Hope this helps and doesn't put you off the idea.

All best

 

[Markymark]

.



I would suggest that, as you have the front batten looking downwards, the rear one should look upwards to act as a rear stop for the books.

Thanks for the replies. When you say a batten looking down do you mean attached on the underside at the front and on the topside at the rear? Sorry a little ignorant when talking tech.

Mark

 

[Argus]

.

Sorry about that….!

What I meant to say was that if, for example, you have a piece of 1” MDF shelf, say 30” long by 8” wide, you need to strengthen it with a batten fixed below.

If you take, say, a 2”x1” batten, rebate a groove, say, 3/8” by 1” and glue the rebate to the front edge, you should have a visible face of 2” when the shelf is in place - the appearance of a shelf that is thicker than it actually is and strengthened the MDF in the process as well as hiding the cut edge of the ‘orrible MDF.

Now, repeating the process on the back edge, you will add more strength. But you have the choice of fixing the batten to mirror the front (pointing downwards) or inverting it so that it points upwards, thereby giving a back stop for the books.

That’s an illustration and the dimensions are arbitrary……..the choice is yours.

.

 

[Andy RV]

It might just be quicker and easier to make it from solid oak? No doubt it would cost more but you'd end up with a better job.

 

[Markymark]

It might just be quicker and easier to make it from solid oak? No doubt it would cost more but you'd end up with a better job.

8 x 4 26mm MDF Veneered with oak both sides is £46+Vat. Not sure what the equivalent in 3/4 Oak would be? I am really , excuse the pun, green when it comes to material prices.

I would love to build it in oak but i have written real wood out as the prices I do not know.


M

 

[nathandavies]

Oak veneered ply for the shelves, and put in an extra shelving strip on the back board

 

[Markymark]

ok £36+ VAT per cubic foot for 1" Oak. Not sure how I calculate what wood I need.

http://www.britishhardwoods.co.uk/timbe ... imber.html

Don't know where to start.

M

 

[Andy RV]

Do you have any machinery available to prepare the timber? If not then you'll pay a premium for planed material. £36+ vat is a bit rich for oak, I've used these guys before and been impressed with the wood and prices, and they deliver: http://www.scawtonsawmill.co.uk/

What depth are your shelves?

 

[Argus]

ok £36+ VAT per cubic foot for 1" Oak. Not sure how I calculate what wood I need.

Don't know where to start.

M

Some years ago, faced with a large amount of sheet material to cut into linear shapes, I made a chart based on a 96" x 48" sheet, divided into 1" squares.
I used it to work out a cutting list.

Dead basic stuff.... you just draw the shapes to size and then count them. Ideal for cutting lists.

If you get in touch, I'll e mail a PDF that you can print off.

.

 

[Markymark]

Andy - I have the kit I have a table saw, Planer, Thicknesser, Band Saw etc.. I love machining timber, Nothing better than the feeling of creating something for the house out of a tree.

With regards to working out the cost of the materials I can work with sheet materials but when buying sawn timber by the cubic metre etc.. I find it difficult I suppose a board of 12" wide, 1" thick and 12' Long is a Cubic Foot?? Not easy when you are down the wood yard and you need to look at the cost of what you are buying.


M

 

[MMUK]

I suppose a board of 12" wide, 1" thick and 12' Long is a Cubic Foot??

Yep, that's correct.

 

[Andy RV]

The way I like to work it out is a cubic foot is made up of 1728 cubic inches (12x12x12), to work out the volume of a board for example a piece 8'x7''x1'' is 672 cubic inches (96x7x1) or 0.39 cubic feet (672/1728).

 

[Markymark]

Anyone know of any hardwood suppliers (small and independent) in the South West. I live near Bridport and can't find many on Internet. The only supplier I found is Devon Hardwoods but I have had differing reviews.

M

 

[rafezetter]

Just a thought, if the back is to be clad then painted, rather than a single sheet, how about each shelf section has it's own false back that also acts as a support, leading from the bottom one which has good load transfer support below, like load bearing walls in a house? It would be less obvious than battens underneath and provide a firm stop for books. Thick MDF would work just fine if the oak costs out to too much money. Incidentally it would also provide a space for wiring for shelf lighting too.

It could be placed a bit away from the rear wall (if its an exterior as mentioned elsewhere) with a few vent holes or something surreptitiously placed so there's no damp transfer or anything to your books. Use a few stop blocks or something to stop it dropping through though if you make it removable.

 

[Markymark]

8x4 Sheets

I have had prices for 26mm Oak vaneered MDF - £45.64 + Vat

or

18mm Oak veneered Ply - £59.00 + VAT

Firstly which would be stronger?

Thanks for all the help and advice but I chose to put two more verticals in making the shelves have a shorter run and the design looks rateher nice. A little more contemporary and no more wood to buy!!

Looking at prices now and not sure on current pricing. The prices are from TP's.

M

 

[Sgian Dubh]

Firstly which would be stronger? M

Ply. A loaded ply shelf will typically bend only about 25-35% as much as an MDF shelf of the same dimensions. For ready reckoning you can simply calculate that ply will carry about 3.5 to 4 times the load of an MDF shelf and show the same amount of deviation from straight, i.e, it will bend the same amount as the lighter loaded MDF. Slainte

 

[Markymark]

Sgian -

Even though the MDF is 26mm thick and the Ply is 18mm Thick??

M