# 2x4s securely bolted to four 4x4 posts enough to hold a 125?



## Jago (Oct 5, 2007)

2x6s could be used if needed but I don't have much vertical space to work with.


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## redblufffishguy (Jul 16, 2009)

1 x 4's attached with deck screws to 1 x 4's is enough to hold a 125 gallon tank. So, YES, 2x4's are plenty strong!!


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## fox (Jun 11, 2009)

Jago said:


> 2x6s could be used if needed but I don't have much vertical space to work with.


2X4 carriage bolted to 4x4 would work just fine. I am not sure about 1x4 & screws though with a 125G tank.

They are not really structural and in 1x4 would only give 0.75" penetration at the most. Besides I have snapped the heads off hundreds of thousands of 'em in the past. Though they provide a very fine mechanical attachment and are not only the best invention since pockets and have also saved my butt on more than a few occassions, the 3/4" worth of threads are just too short.


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## Rick_Lindsey (Aug 26, 2002)

I presume that RBFG's hypothetical 1x4 stand has the weight directly supported on the 1x4 legs rather than on a 1x4 frame that is screwed to the 1x4 legs in a manner that the screws are having to support the tank...

-Rick (the armchair aquarist, who lusts after a pocket-hole jig)


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## bntbrl (Apr 23, 2009)

Im my experience with 4x4 posts from the home improvement places is that they arent fully dry to begin with, and when they get wet and rewet in a moist humid environment they tent to twist. I dont know why they twist. I no longer use 4x4s but 2 2x4s. Maybe someone else can chime in on that.

1x4s vertically are strong, not horizontally though. All dimensional wood is strongest going with the grain from the floor up or against the load.


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## fox (Jun 11, 2009)

Rick_Lindsey said:


> I presume that RBFG's hypothetical 1x4 stand has the weight directly supported on the 1x4 legs rather than on a 1x4 frame that is screwed to the 1x4 legs in a manner that the screws are having to support the tank...
> 
> -Rick (the armchair aquarist, who lusts after a pocket-hole jig)


Thats what is wrong with this internet thingie, too much wiggle room for misinterpretation, you are prolly right as the stand supporting our 210 is basically 1 x 4's.


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## redblufffishguy (Jul 16, 2009)

Look back at my previous post....

http://www.cichlid-forum.com/phpBB/view ... highlight=

I know that stand I built is only a 40 gallon, but I have built them in the exact same way for 125 and 240 gallon tanks!!!

Rick, the tank could sit on the frame or the legs. If you put it on the frame more screws are required for shear, but it is totally possible.

Fox, Deck screws come in many lengths, and have a shear strength of 100's of pounds!! The stand in my post is constructed using 1-1/2" pocket screws. The diameter of the pocket screws is less than that of a deck screw.

Obviously I am not saying you could put a frame around 4 legs and expect it to hold a tank, there would be zero lateral support! My point is that the vertical crush load for 1 x 4 material is well over 1000 pounds per square inch. 2x4's or 4x4's are way overkill!

There is nothing wrong with overkill, it just is not necessary. But if it gives you peace of mind, by all means over kill it!!

RBFG


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## fox (Jun 11, 2009)

red I agree on the 1 x 4's. I'm a builder with 37 years in the trade. 4 x 4's are over kill Be Sure.

The deck screws are also prolly more than enough also in terms of shear and definately better than drywall screws which are tempered.

The problem is the length of contact between wood and thread when using 3/4" material to build. You would be surprised how little weight 0.75" of thread can support if it is the screws you are relying upon to support the load. The type of material used is a consideration for sure but using Spruce, D Fir, White or Yellow Pine and you need inches of thread for a tank of say 125 G and more. One or even two 3/16" carriage bolts will support more than nine 1-1/2 #8 deck screws is all I was tring to say. Sorry if I came across as a jerk.

Now building techniques such as rabbiting or mortising will make this all moot.


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## Mcdaphnia (Dec 16, 2003)

bntbrl said:


> Im my experience with 4x4 posts from the home improvement places is that they arent fully dry to begin with, and when they get wet and rewet in a moist humid environment they tent to twist. I dont know why they twist. I no longer use 4x4s but 2 2x4s. Maybe someone else can chime in on that.
> 
> 1x4s vertically are strong, not horizontally though. All dimensional wood is strongest going with the grain from the floor up or against the load.


Not only are 4 by 4's prone to twisting, there is an ominous reason for it. Typically 4 by 4's are treated for outdoor use and should not be used indoors. They have been soaked after kiln drying in a chemical bath and that moisture is not completely removed. Because of the part of the tree's cross section that 4 by 4's are made from, they are more likely to bleed. Softwood bleeds resin, not blood.

If you want 4 by 4 dimensions but much better strength and stability, you have at least two options. 1. Pick two 2 by 4's with opposing grain. Sandwich a half inch plywood strip between them and screw and glue together. 2. Use two 1 by 4's and two 1 by 3's, and screw and glue them together to form a box beam. Lighter and in some directions stronger than the 4 by 4. If you want it even stronger, an internal diagonal the length of the beam will give it additional strength


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## DrgRcr (Jun 23, 2009)

Plywood baby, plywood!


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## redblufffishguy (Jul 16, 2009)

Fox, You definately did not come off as a jerk.....

However you are incorrect about the strength of screws. Testing has proven that "Kreg" brand pocket screws (very simmilar to deck screws in thread pattern and thread length) when use 2 per joint will hold over 707#. translate that to an even load spread across the 4 corners and your load capacity becomes 2828#.

A 125 gallon tank will weigh about 1200# once the tank weight and decor weight are added to the water weight.

I do agree that a carriage bolt is substantially stronger though. And not every one has the skill or knowledge to use pocket screws, or to build using methods other than those that will result in overkill.

But back to the original question: YES, 2x4 materail is plenty strong to support your tank.

RBFG


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## Mcdaphnia (Dec 16, 2003)

redblufffishguy said:


> .... Testing has proven that "Kreg" brand pocket screws (very simmilar to deck screws in thread pattern and thread length) when use 2 per joint will hold over 707#. translate that to an even load spread across the 4 corners and your load capacity becomes 2828#.....RBFG


Deck screws, even ones that are improved with a thicker shank near the head still are very prone to popping off. I don't think they would equate to a Kreg screw or to an ordinary furniture screw. Comparing strength tests done in hardwood to spruce/pine/fir is comparing apples to orange balloons.

http://www.kregtool.com/

Carriage bolts please.


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## pistolpete (Dec 28, 2009)

I would like to chime in on this debate. Crush strength of 1x4 wood is indeed more than adequate to support larger tanks, however you quickly run into issues with the slenderness ratio. you can run a 1x4 cutoff over with a truck and it will not be worse for wear, hence the 1000+ pound crush strength. However, if you balance 200 pounds on top of an eight foot 1x4 upright it will likely buckle and snap.

Tanks stands need to be designed to handle not just vertical loads, but also horizontal stresses applied by the occasional drunk house guest. Bracing needs to be applied to the back of the stand, usually in the form of plywood gussets. By far the most solid stands I have built are made of 2x4's in a "L" configuration on the corners, 2x4 cross members, and a 1/2 inch plywood skin over the whole thing. Screws should never be used to support any of the weight of the tank, the weight should be carried directly to the floor by the corner posts.


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## Mcdaphnia (Dec 16, 2003)

pistolpete said:


> I would like to chime in on this debate. Crush strength of 1x4 wood is indeed more than adequate to support larger tanks, however you quickly run into issues with the slenderness ratio. you can run a 1x4 cutoff over with a truck and it will not be worse for wear, hence the 1000+ pound crush strength. However, if you balance 200 pounds on top of an eight foot 1x4 upright it will likely buckle and snap.
> 
> Tanks stands need to be designed to handle not just vertical loads, but also horizontal stresses applied by the occasional drunk house guest. Bracing needs to be applied to the back of the stand, usually in the form of plywood gussets. By far the most solid stands I have built are made of 2x4's in a "L" configuration on the corners, 2x4 cross members, and a 1/2 inch plywood skin over the whole thing. Screws should never be used to support any of the weight of the tank, the weight should be carried directly to the floor by the corner posts.


Good points! Screws mostly act as clamps to hold the wood together while the glue dries. In soft wood, screws too easily shear and pull out under any stress from any direction. The most solid SPF stands I've built "stack" the wood, never depending on a screw or bracket to hold weight.

http://www.cichlid-forum.com/articles/diy_stand2.php

Plywood in three dimensions (front to back, left to right, and horizontally) braces the stand, and is set in to a channel as much as possible so it won't drift. Multi tank stands are built in modular form so they can be moved and re-arranged as needs change.


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## redblufffishguy (Jul 16, 2009)

This thread has become frustrating....

There is absolutely no need for 2x4's in an aquarium stand!!!!!!

I addressed the horizontal (lateral) support in an earlier post, It is tollaly needed and can be done with plywood, or 1-by material.

Deck screws, at least the one I use are as strong or stronger than kreg screws! I am talking about the onse that are coated to prevent rust. They have a thicker diameter than the kreg screws, and rarely "pop off".

Pistolpete: Who one earth would build a stand 8 feet tall???? Clearly I was talking about the crush strength for a 1 x 4 that is in the range of a typical height of an aquarium stand. I build them 24" and 30" tall.

If I am coming off like a jerk, I do appologise, but I have been building aquarium stands for at least 15 years (commercially and as a hobby) I have built porbably 1000's of them. I have never used 2x material!!!! I use both 1-by material and 3/4" plywood depending on the customers budget. I use glue on all of the joints, and until 4-5 years ago, I did NOT use any mechanical fasteners (IE screws)! I have NEVER had a stand fail!

Blast me if you want, but in my proffesional experiance, the advice typically given on this forum errs on overkill, and is taken as the gospel. My version of an aquarium stand is proven, effective, and doable.

Take this post for what it is worth, and Jago, my appologies for the rant....I do hope you question about the 2x6 vs 2x4 has been answered.


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## Mcdaphnia (Dec 16, 2003)

redblufffishguy said:


> This thread has become frustrating....
> 
> There is absolutely no need for 2x4's in an aquarium stand!!!!!!


 SPF 2 by 4's are cheaper than even a poplar one by four. If there a is a need for cheapness, they can make sense, but as to needing 2 by 4's..... not so much!



redblufffishguy said:


> I addressed the horizontal (lateral) support in an earlier post, It is tollaly needed and can be done with plywood, or 1-by material.


 Agree with you totally on this. I've seen pet shop stands sway and collapse. Even when they rebuilt the stands, they doubled all the 2 by 4's but would not add any bracing. All that surprised me was how many months they lasted before the second collapse.



redblufffishguy said:


> Deck screws, at least the one I use are as strong or stronger than kreg screws! I am talking about the onse that are coated to prevent rust. They have a thicker diameter than the kreg screws, and rarely "pop off".


 I have yet to meet an uncoated deck screw. Even after replacing dozens of deck screws, I have still more to replace.



redblufffishguy said:


> Pistolpete: Who one earth would build a stand 8 feet tall???? Clearly I was talking about the crush strength for a 1 x 4 that is in the range of a typical height of an aquarium stand. I build them 24" and 30" tall.


 Triple and double tier stands



redblufffishguy said:


> If I am coming off like a jerk, I do appologise, but I have been building aquarium stands for at least 15 years (commercially and as a hobby) I have built porbably 1000's of them. I have never used 2x material!!!! I use both 1-by material and 3/4" plywood depending on the customers budget. I use glue on all of the joints, and until 4-5 years ago, I did NOT use any mechanical fasteners (IE screws)! I have NEVER had a stand fail!


 opcorn:



redblufffishguy said:


> Blast me if you want, but in my proffesional experiance, the advice typically given on this forum errs on overkill, and is taken as the gospel. My version of an aquarium stand is proven, effective, and doable.





redblufffishguy said:


> Take this post for what it is worth, and Jago, my appologies for the rant....I do hope you question about the 2x6 vs 2x4 has been answered.


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## pistolpete (Dec 28, 2009)

When I mentioned eight feet, I was making a point about the slenderness ratio and how it relates to crush strength. The slenderness ratio is the ratio of height to the minimum cross section of a piece of lumber. When you reach a ratio of around 20, most lumber will buckle rather than crush, so crush strength ceases to be the limiting factor. for 3/4 inch material that is only 15 inches.

redbluff, with your precise joinery and good gluing techniques, yes, you are absolutely right. 3/4 inch material is plenty good. But even your corners are securely fastened in an "L" configuration and reinforced, resulting in what amounts to a laminated 2x4. There are lots of people on this forum with a skill saw and a drill, interested in building stands. For them 2x4's are the best material to work with.


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## Rick_Lindsey (Aug 26, 2002)

pistolpete said:


> There are lots of people on this forum with a skill saw and a drill, interested in building stands. For them 2x4's are the best material to work with.


Certainly the cheapest! I've been pondering a 1x4 skinned in 1/4" plywood stand for some time, trying to figure out how to do it with my skil-saw and drill . I'm leaning towards attaching the verticals to the plywood first, then attaching the top/bottom frames... so in the end I have a solid line of 1x4 (top frame -> vertical -> bottom frame) to support the weight, but the 1/4" plywood skin helped me get/hold everything in place during assembly so I'm not trying to attach the butt-end of a 1x4 board to my frame in mid-air, and avoiding the need for doubled-up 1x4 (which was my other thought... make veritcals laminated from two 1x4's, one of them to go between the top/bottom frame and the other to screw to the top/bottom frame from the inside)

-Rick (the armchair aquarist, who wishes he would quit losing the little plans he draws up)


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## redblufffishguy (Jul 16, 2009)

Pistolpete,

I totally agree with you! I have never said that using 2x4 is not a good idea. I agree that with limited knowledge of carpentry, and limited tools, 2x4 construction is warranted.

My point this entire time has been that it is overkill. Most who post on this forum beileve that 2x construction is necessary. My point is that it is not!!

I also agree the long lumber will buckle. However, once you attach horizontal members to the long vertical member, you have effectively shortened that board. I mean that the areas that will flex and buckle now are only the distance between the horizontal members. Of course the connection needs to be made with either dado joints and glue, or with mechanical fasteners.

RBFG


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## Jago (Oct 5, 2007)

My girlfriends dad has some time on his hands so he's kind of pushed me aside and gone gung ho on this project. I'm not complaining. But talk about overkill. Or I guess we could just call it peace of mind. Or you could call it a tornado/bomb shelter. Dorothy would of been just fine if she could of just got under my 125s.

Some details on the project: We're building an L shaped stand in the corner of my basement for two 125s, 75, 55, and a 20. At least that's what I think will go on it. I'll post pics once the long part of the L take shape.


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## Mcdaphnia (Dec 16, 2003)

Jago said:


> Some details on the project: We're building an L shaped stand in the corner of my basement for two 125s, 75, 55, and a 20.


L shapes can be trouble. Hard to keep square and flat, Hard to level. Easy to get a twist in the structure. Very hard to get up or down the stairs or through a hall way.

Two rectangular stands that can be set as an L would be lots better.


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## Charlutz (Mar 13, 2006)

redblufffishguy said:


> 1 x 4's attached with deck screws to 1 x 4's is enough to hold a 125 gallon tank. So, YES, 2x4's are plenty strong!!


RBFG, the reason you are finding the need to apologize is because your posts in this thread were not meant to help the original poster. Instead, you are trying to make the point that when properly engineered, you can use many other materials besides two by fours to build a stand sufficient to hold a 125. You haven't said anything untrue, but it is unrealistic to believe that a poster asking the question of whether screwing 2x4s to posts would hold a 125 actually has access to pocket hole jigs, kreg screws and was also going to skin the tank in plywood. I find it much more likely that the OP was looking to build a simple double rectangle skeleton frame stand and your answer could get him into trouble.

If you are building a frame stand, there is also the need for some support to prevent deflection of the tank rails. In your thread, you use plywood. For a frame stand, you can do it with center posts, but 2x4's screwed to four posts as the OP proposed would not be sufficient to prevent the stand from bowing toward the center of the tank. I've built far less stands than you (only about 15), but from talking to engineers and builders, a single 2x4 rail 6 feet long would deflect under the weight of a 125. I've also never seen a stand built that way, which is what the OP seemed to be asking.


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## staples2485 (Aug 13, 2007)

sorry this thread makes me laugh you people really do overkill your stands 4x4 bolts 2x4s i mean they are way easier to build with lack of tools. The ones with solid plywood weigh much less and look better, but you really need to know what your doing. The average fish keeper would flip if they saw some of the supports everyday stuctures have. When i started making stands i would always go crazy with the wood screws and bolts, then one day my grandfather and uncle who are both contractors laughed at my stand and told me they do not even beef up a house that much! Than i used their knowlege and started scaling down. This really helped my making my stands a lot lighter.


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## redblufffishguy (Jul 16, 2009)

Charlutz...

The only way there would be a significant or noticable amount of deflection in a six foot 2 x 4 used horizontally in a aquarium stand would be if the aquarium was plexiglass. Glass aquariums simply do not bow or flex in a vertical direction. A glass tank supported at the 4 corners will not deflect at the center point. At least not enough to notice. AND, a 2 x 4 is way more than adequet to carry the load over a six foot span.

A 125 gallon aquarium only applies about 80 pound per foot of stand. IE: 6' front, 6' back, 2' right side, 2' left side. total linear footage= 16'. Total weight of tank plus water plus misc is about 1250 pounds. The force will be equal all the way around, giving you the (aprox) 80 pounds per foot.

2 x 4 lumber is rated well over that weight. And that doesn't even take into consideration the load that is being applied to the vertical members. It would be safe to say that the vertical members will absorb at least 40 percent of the load.

Having said that, I agree that if you applied 1000 pounds to the center portion of a six foot 2 x 4, there would be bowing, and possible failure, but that simply is not the case.

As for "OP was looking to build a simple double rectangle skeleton frame stand".... I addressed that in the beginning, there is the need for lateral support!

RBFG


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## Jago (Oct 5, 2007)

Mcdaphnia said:


> Jago said:
> 
> 
> > Some details on the project: We're building an L shaped stand in the corner of my basement for two 125s, 75, 55, and a 20.
> ...


The hard to level part brought a smile to my face. But not for good reason, my house is a century old this year, many things are tough to level. It basically is two long rectangles that will be attached to form two levels of continuous shelving across one corner of my basement.

I can't wait to see my two big tanks on it instead of sitting empty on my front porch.


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## Mcdaphnia (Dec 16, 2003)

Jago said:


> Mcdaphnia said:
> 
> 
> > Jago said:
> ...


 I was not referring to your floor. I meant internally keeping the L shape stand level.

Unlevel old basement floors are around. One guy built his fish room and gave up on trying to level a stand on the floor. He hung 2 by 4's from the ceiling joists and then hung his aquariums from them.


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## pistolpete (Dec 28, 2009)

Charlutz, RBFg is correct, you can put a 125 glass tank with the corners on four stacks of cement blocks and it will be just fine. A tank in itself acts like a beam and will not sag in the middle. so the only concern is lateral stability of the legs, not the dimension of the rails.


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## Mcdaphnia (Dec 16, 2003)

pistolpete said:


> Charlutz, RBFg is correct, you can put a 125 glass tank with the corners on four stacks of cement blocks and it will be just fine. A tank in itself acts like a beam and will not sag in the middle. so the only concern is lateral stability of the legs, not the dimension of the rails.


 I have a 90 which I bought used. The seller's fish room was all on cinder blocks, even six foot long tanks were supported only on the ends. The 90 had about 8" of gravel in it, and was set up supported only on one end and in the middle. Almost half the tank jutted out into thin air.


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## Charlutz (Mar 13, 2006)

My first attempt at building a stand (long before the internet was around) was a 2x4 post and 2x4 rail stand for a 55g. The stand sagged in the middle and the front glass cracked. I'll stick to my way.



pistolpete said:


> Charlutz, RBFg is correct, you can put a 125 glass tank with the corners on four stacks of cement blocks and it will be just fine. A tank in itself acts like a beam and will not sag in the middle. so the only concern is lateral stability of the legs, not the dimension of the rails.


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## fox (Jun 11, 2009)

Charlutz said:


> >snip< The stand sagged in the middle and the front glass cracked. I'll stick to my way.
> 
> We have a 6' 210G tank that is supported at the two sides only with 3/4" stand. The midle does not sag. Mebbe your stand was not "True" and had a high spot in the center area.


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