How to reinforce a shelf for a fish tank?

[loubang]

Hey all, wondering if it would be possible to reinforce the top shelf of this shelf unit.

I've been wanting to put a 22G long fishtank (90x 30 x 30cm - just over 100kgs when stocked) in this spot but I've been having a nightmare with getting shelving solutions that aren't incredibly costly or incredibly ugly.

This bookshelf is 100cm wide, 31cm deep, and at 50cm and 100cm there are 1 inch studs. The shelf itself is mdf and unreliable, but I'm wondering if I could conceal a supporting shelf behind this top front piece.

My idea is to attach some heavy duty shelf brackets (rated at 200kg load capacity, like these) to the studs, and then afix a solid plank of timber to the brackets to run the length of the top shelf, and then screw the mdf top shelf to the concealed supporting shelf.

Would this work? I don't have much experience with things like this so I'm looking for any and all advice

[EricL]

Hello @loubang 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your table.

Even though the parts you are attaching to the bookcase are strong, the MDF material of the bookcase itself is not. Therefore, even with multiple supports the weakest link is the MDF itself. 100kgs is a lot of weight and is equivalent to three midsize toilets. I propose building a dedicated table to hold your fish tank, I suggest using 70x35 framing timber and Specrite 1200 x 405 x 18mm Timber Multi Use Pine Panel - Bunnings Australia.

You'll need a saw, tape measure, drill and drill bits to assemble this table. I've placed some sample images below to give you an idea of how you can build it. Please note that the measurements are for reference only, please adjust them to your needs.

If you need further assistance, please let us know.

Eric

[loubang]

Thanks for the response. I know the mdf itself isn't strong, which is why I'm wanting to make a reinforcing shelf underneath it. The existing mdf/shelf would effectively just be an aesthetic shell to cover the more utilitarian bracketed shelf.

Is mdf still a problem if layered onto a more durable timber plank (or timber framing)? Would it be less troublesome to entirely remove that mdf top piece and just use a plank on heavy duty brackets??

[JacobZ]

Hi @loubang,

Ultimately, the bookcases aren't ideal, and it's hard to say for sure because I can't check the bookcase myself. A design like @EricL's, through the use of solid timber framing, would ensure it is properly supported, but I think it should be fine to keep the MDF with some additions to strengthen it. MDF is not weak, it just needs to be supported with hardware and framing to ensure the weight is distributed and supported.

Adding heavy-duty brackets that are screwed into the studs is a must. I would, however, suggest you try to maximise their length coming out from the wall to ensure the front edge of the shelf is well supported. These Carinya 250 x 200mm Black Angle Brackets, would be better suited.

You should also add a 70x35 ladder frame underneath the top shelf and screw through the side walls of the bookcase to connect this frame to the bookcases vertical support. 

Something like this should work.

This design should be strong enough to support 100kg, but adding legs at the front edge would be ideal.

 

This would mean you'd have to notch out a space in each shelf to allow the legs to run through to the ground. This wouldn't be too difficult to do, but it would be a fair bit of extra work. You could then attach some white melamine to the front of these legs to conceal them.

Let me know what you think.

Allow me to tag @Dave-1, @JoeAzza and @Nailbag for their thoughts.

Jacob

[loubang]

I really like this idea! If I added legs at the back of the shelf as well could that eliminate the need for the brackets? I would still have one from the centre into the stud for additional support and stability.

Thank you for your response! 😊

[Dave-1]

Good Afternoon @loubang 

Ive had a lot of fishtanks over a bunch of years. They have alwas sat on solid timber framed benches or stands, never particle board (Was rolling back through my memories lol)

I like @EricL's design to hold the tank, Other things to consider are external filters and such, water and particle board dont mix to well, and usually by the time we notice there is a leak from something then the particle board will be wet wet. Im not hugely keen on brackets holding weight such as a fishtank either.

Why not build a frame like the one @EricL has suggested but modify it so you can "clad" it so it looks like one of your existing bookshelves? It may take a little more working but the peace of mind your tank will be there and be there without cracks overnight is really worth it.

Dave

[loubang]

Thank you all for your responses-

I initially wanted to reinforce this shelf as I hadn't been able to find a suitable structure that wasn't either ugly or super expensive. 

My original idea was a garage shelving rack rated for 200kgs per shelf, however I was unable to order the specific one I was looking for through my local Bunnings as the variant I wanted was not something that store carried. 

I have since been able to find a store that is a little further out that carries the unit I've been looking for and they have assured me that they will be in stock later this week.

Thank you for time and input on this! This was obviously my first time using the Bunnings forum and it most certainly won't be my last! 

[Dave-1]

Afternoon @loubang 

As a note I bought some pine timber cabinetry decades ago from one of the "Cheap furniture places" (not partical board) and they were used for multiple 4ft fishtanks without an issue (Had a sheet of strofoam under them of course) These I used for years as fistank stands, then an old school 80cm CRT tv stand without an issue. Maybe have a look in one of those stores, look for pine  with not partical board or MDF

Dave

[EricL]

Hi @loubang 

Please keep us updated with your progress, we look forward to seeing your large aquarium tank set up and ready to go.

If you need further assistance, please let us know.

Eric

[Nailbag]

Hi @loubang 

I think for the amount of effort to pull partly apart and modify the current, shelf, it would be far better to perhaps custom build one yourself to support the weight and then adapt the bookshelf off that. The design @EricL has sketched would be a terrific head start.

Nailba