How much weight can a 3/4'' Plywood Hold?

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Forum topic by DeepDave posted 05-29-2018 12:44 PM 8412 views 0 times favorited 7 replies Add to Favorites Watch
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2 posts in 1012 days

05-29-2018 12:44 PM

Hi All,

This is my 1st post and I hope I am posting in the right section. :)

I have got an Aquarium Stand made which is 36 by 30 (Inch). Unfortunately, the guy who designed the stand did not put Aluminium Plates in between to support the 400-500 Kg Aquarium weight.

I was wondering If I put 3/4’’ Plywood in between, will it take so much weight?

My stand looks something like this -

This is not my stand, just a google image that looks similar.


7 replies so far

View tmasondarnell's profile


150 posts in 2803 days

#1 posted 05-29-2018 01:50 PM

It’s complicated.

What does the bottom of the aquarium look like? Does it have a lip around the edge or is it a flat bottom? How the load of the water is distributed is important.

Also, how big is the stand in relation to the tank? Is the stand a snug fit so that a good portion of the weight is directly being born by the stand (e.g. if there was no wood shelf could the tank rest on the stand support) or will the tank be inset from the side rails?

If the tank has a lip around the bottom edge and can rest on the metal edge of the stand without a shelf, then the thickness of the wood is irrelevant. There is a direct load path.

View ocean's profile


228 posts in 1847 days

#2 posted 05-29-2018 03:13 PM

The wood will ultimately get some water on it. That will continue to be the case for months and years to come and will ultimately rot the wood. With a load of 880-1100 pounds I would not depend on wood for support. Way is much weight for 3/4 ply. It need to be supported as tnasondarnell said. Bear the weight threw the frame and legs. You will also have to be concerned the the floor below your stand. A static load of that size is hard to measure without seeing your floor and want it is made of. Best answer is to have your stand modified to fit your aquarium and to talk with someone in the business as to load. Be careful, it will create a real mess if you get it wrong.

-- Bob, FL Keys

View ClammyBallz's profile


449 posts in 2151 days

#3 posted 05-29-2018 07:02 PM

You want to put plywood on the top?
Is the bottom of the aquarium glass or is there a plastic frame?

View John Smith's profile

John Smith

2866 posts in 1177 days

#4 posted 05-29-2018 07:19 PM

my brother had to jack up his living room floor from underneath
and add additional support posts – just something to consider.

-- there is no educational alternative to having a front row seat in the School of Hard Knocks. --

View Rich's profile (online now)


6581 posts in 1603 days

#5 posted 05-29-2018 07:52 PM

A well constructed aquarium will stand on its own. What’s critical is that the base be supported perfectly flat. The legs in the corner of the stand will support the load, there’s no need for a plywood base other than to stiffen the frame of the stand and make it more stable.

The killer would be if one corner were even a fraction of an inch lower than the rest because the weight of the water would cause the aquarium to twist and it would leak at a minimum and possible fail, which would be nasty to come home to.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

View DeepDave's profile


2 posts in 1012 days

#6 posted 05-30-2018 04:46 AM


Thank you all for the replies.. :)

I had with a help of a Welder, welded a support in between.. Besides, added 2 nos of 3/4’’ plywood on top to distribute the weight..

The problem is, the metal strip that was welded, is a bit tilted by the welders error which is causing the plywood to seesaw a bit.

I guess I will have to add cardboard under both sides to stop that rocking.

Thanks a ton guys..
Deep :)

View Kelly's profile


3389 posts in 3958 days

#7 posted 05-31-2018 03:39 PM

I have carts of plywood that support five hundred pounds without a shrug. I suspect they’d hold a half ton, but the wheels would not like it. It all boils down to open space and what’s under it.

The picture you showed indicates there would be enough room to put stiffners under the ply.

You could make a picture frame of ply on end. The frame would mount to the bottom of a flat piece of ply and be inset enough to allow you to drop it into the metal frame. “Stringers” (stiffners) could run across the frame and the whole thing could be glued and screwed together.

I wouldn’t worry horribly much about water, if I sealed the wood well. After all, if you always have water on the wood, you’ve got bigger problems. Many aquarium stands are made of solid and plywood.

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