How to build long floating bookshelves in home office?

[magsr]

Hi Experts!

I'm a home reno novice.  I've removed paint, sanded and repainted a side board.  

I'd really like to build floating shelves for books above my desk in my home office.

Something like this only longer and in a natural oak timber colour: 

It's a 4m long wall. So I'm hoping to have at least a 3m long shelf, 40cm deep.   It's to be mounted against a blockwork wall (middle apartment) so I should be able to secure something pretty strong.

I'd like it made from a decent piece of timber - I wanted live edge but that's getting a bit out of my price range, so now I'm thinking pine or tasman oak timber.  I'm going to look on the weekend for reclaimed timber if I can find a piece long enough but they probably will be shorter.

How do I support this shelf?  Is it with those chemset bolts?  With the angle brackets?  How do I work out how many I need, required spacing and how much loading capacity it will hold?   The wood itself is going to be heavy, and then loading it with books will be heavier again.  I don't want it to warp/sag/cause injury.   

Is it possible to do it with two smaller pieces of timber?  How would I do this?

Many thanks

Mags

[JacobZ]

Hi @magsr,

A warm welcome to the Bunnings Workshop community and thank you for your question.

There are options for both pine and tasman oak such as this Specrite 1800 x 405 x 18mm Pine Panel or this 1800 x 405 x 19mm Tasmanian Oak Panel that might be good options for you.

There are a few different ways you can support your shelves, with the easiest being angle brackets.

These Carinya 380 x 380mm Black Angle Brackets would work well as they sit 380mm out from the wall, so the full length of the shelf would be supported. They could be attached to the wall using blue wall plugs and 50mm screws. 

According to the Carinya website, the Heavy Duty Extra Strength Angle Brackets are rated to support 50kg each when spaced at 415mm apart. As long as you are not exceeding this weight sitting over one bracket, then you should be fine.

You could certainly do it with two pieces of timber, however, you would need to add extra support to the join and use an angle bracket on each side of the join. You could also use joining plates to support the joint.

Allow me to tag @Dave-1 and @Nailbag to see if they have any other ideas for your project.

Jacob

[Nailbag]

HI @magsr 

I'll be honest and say you have given yourself a very challenging project as a novice DIY'r. A 3m long x 400mm + thickness is going to be "extremely" heavy to say the least. Installation will requirer as you said, steel rods chemsetted in to the wall. To be successfully, this itself requires a pneumatic hammer drill using a 4-cut drill bit and the hole vacuumed. The holes need to be made perfectly horizontal and plumb. Then the holes in the shelf need to match the location vertically and horizontally and within the depth of the shelf. This really requires a professional installation.

If you want to install this yourself, I suggest considering "stayed" shelf brackets using the fasteners @JacobZ suggested as far more achievable project. And that is still above beginner level in my opinion. But we are here to help if toys still decide to have a crack.

Regards, Nailbag

[Dave-1]

Good Evening @magsr

Thats a fair sized shelf weight plus books plus ??? more books on it. It makes me hessitant to go that floating shelf route due to the overall weight. Its doable but generally something I wouldnt do. I prefer brackets but then you will loose the clean lines so I really get why you want the flkoating shelf style.

Having a narrower shelf being floating (say 250mm) would be a wiser option engineering wise. Tho I still like brackets.

Do you have a photo of the wall that we could see as it may add some ideas to how it can be done?

Dave

[magsr]

Thanks Jacobz.

Ah 50kg at 415mm spacing.

I saw one of the black heavy duty ones saying it had carrying  capacity of 150kg but couldn't see what spacing that meant it needed to be, when online trying to purchase. How do I find this out  for the other bracket options?

[magsr]

Thanks @Nailbag.

How much weight would the chemist stuff hold? 

And how heavy would this size timber be?

Trying to work out roughly how strong it would be and if it can carry the books or if I need to find a different way to do this...

Thanks

Mags

[magsr]

Thanks @Dave-1 

250mm is a bit thin for the books I need to put on the shelf as some are quite  large collector tomes and ideally we'd like to put one of those 37x37x37 cube type foldable boxes to store other things in between.

Its to be located above our desks so I don't want things to be falling off.

I can take a photo of the wall but it's just a white long wall. At one end is an almost full height glass sliding doors and the other end is a wall.

The walls have a little bumpy surface so I assume that means plaster, or whatever they use to cover the blockwork walls that isn't gyprock, was used....

We have some desks pushed up against it at the moment at typical desk height and I'm wanting these shelves to be up high above the desks to make use of the dead space there.

What weight should I be estimating to be loading up the brackets here? Is there a guide for kg/m of timber?

And I can weigh our boxes of books but there are a number of boxes so I know we have probably close to 100kg of books to home somewhere.

How do I find the right brackets that can handle the weight capacity we need? I cant find the information when looking at the brackets on the online shopping of bunnings.

What brackets do you recommend and what spacing and weight capacity will that give?

Thanks for the advice.

Regards

Mags

[EricL]

Hello @magsr 

Can you please tell me the model number or item number of the shelf that you saw? Perhaps I can find an instruction manual on the Bunnings website that will tell us the spacing it needs to be mounted. Otherwise, I propose visiting your local store and having a look at the fixing points in the bracket system of the shelf. 

How much weight can a chemical anchor hold if we are talking about Chemset for example? Chemset is rated at 12.2MPa in which is conservatively equivalent to 123kg in tensile strength. But this holding power is also dependent on the material its being anchored onto. 

If you need further assistance, please let us know.

Eric

[Nailbag]

Hi @magsr 

There are too many variable to provide a more accurate answer sorry.If you really want such a long and deep shelf and be confident of security, I would have not professionally installed.

Nailbag

[Dave-1]

Morning @magsr 

Pretty much along the lines of @Nailbag  is my way of thinking, Its your books and stuff that will be sitting on the shelf.

The weight rating of the brackets are pretty much always there on the Bunnings site under the specifcations.

As an example of Carinya 250 x 200mm Black Heavy Duty Straight Stayed Bracket 

I think of stand alone bookshelves and the span of the shelf plus the sag you will recognise from poorly supported shelves you have seen over the years. This is how I arrive at my "prefferance" of support for a shelf. You can have a thinner shelf  but a backplane to the shelf itself to give it added strength (think of an "L" Lying down on the job), you can have the thicker shelf that you want and structually it will be the same.

With the brackets, think of the "sag" factor, the spacing between your supports, With the right angle supports I see them as stronger then a straight rodd out from the wall, no matter what you use to attach the bar/angle to the wall (chemset/bolt/screw)

Easiest way I can show how much weight it will be carrying is to get a piece of timber, hang it so 400mm is over space and 400mm is on the bench, place some bricks or something heavy with the part sitting on the bench. Then load up the part that is hanging in space. Very soon you will see what a certain weight can hold, A right angled bracket tranbsfers the weight so much better to the attachment points.

Dave