How many shims are too many shims

[angnak]

Couldn't find a definitive answer but the few threads I read the max I saw was about 1/4".

My situation. I am building a house and the fish room has a drain in the floor. The drain was supposed to be offset in the room but got put in the center. Not a big deal because still has room for the tank. Tank is 8'x3'x3' and building the front part of the stand as the wall from the viewing room. So the back half needs shims. One side appears to need about 11/16" and the other side 9/16". The plan is to start at a corner and go every foot or so at first. Then come back and fill in more in between. Then fill in the gaps more until it is basically a huge wedge in there to help disperse the weight. Thoughts on the plan? Is that too much shimming? LFS says it will be fine but still pretty nervous.

Floor is vinyl on concrete.

 

[ca1ore]

Stacking shims is no problem, just try to use them properly (insert one from either side so they 'nest'). I needed almost 3/4" on one corner of my 265 (old house, uneven floors). Been fine for 4 years.

 

[Reefpuck]

Shims work fine. I'd start with a thin 1/2" strip of wood running the length of the gap, then fill the rest in with shims. Give you a little more consistency.

 

[krazyk148]

I sealed the outer edges of the gap and then pumped in concrete. Of course mine is in the basement on a slab and is super permanent haha

 

[davocean]

I would take a level and find the lowest spot and how much that is out, stack accordingly and then fill the void below about every 6" to where those are snug.

I usually will add a dab of silicone if there are a lot of shims just to keep them in place until tank is full and weight locks all down in place.

 

[billdogg]

Shims work fine. I'd start with a thin 1/2" strip of wood running the length of the gap, then fill the rest in with shims. Give you a little more consistency.

This

I would take a level and find the lowest spot and how much that is out, stack accordingly and then fill the void below about every 6" to where those are snug.

I usually will add a dab of silicone if there are a lot of shims just to keep them in place until tank is full and weight locks all down in place.

and this.

Ideally you will place them in a solid line everywhere they are needed. In reality, every 6-12" should be fine if the stand is properly built.

 

[angnak]

Thanks, everyone! Makes me feel better. I appreciate the feedback. Will definitely apply it to the stand. I'll eventually start a tank build thread. Thanks again

 

[Lsufan]

I would use something to get u close then shim up from that. It would be easier then trying to stack 3 & 4 shims ontop of each other. Using only shims would work & if u go this route I would do like Dave mentioned & eighther silicone or use a little wood glue inbetween them to hold them together.

 

[angnak]

Thanks. Makes sense to build it up before the shims start.

 

[der_wille_zur_macht]

What's the construction of the stand like?

When I had my 360g, it was essentially in wall with a stand framed with 2x lumber. I built a top and bottom frame, tacked the top frame to temporary legs to hold it totally level at the desired height, then measured and cut the vertical posts one at a time as needed. This way, the stand was essentially built to fit the uneven floor but maintain a level and flat surface for the tank.

On a smaller system I would definitely just shim, but if you're building a stand in-place for a large tank or one that will never move, you might as well just build in the correction. That said I don't think there is anything wrong with shimming.

 

[azsoccerpop]

You can get shims that are composite making them waterproof and less likely to compress over time at home depot


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[angnak]

I thought about that and I was building the stand where I could just build the correction in. My concern there was putting any angle that may introduce some instability because the load would be pushing at that angle vs 90*. I am not an engineer so not sure if that would be the case or not. Thanks for the suggestion.

I like the composite route due to the size and weight of the tank. I was going to go with composite shims. Maybe a mix of composite and cedar. Mostly the composite and then fill in with the cedar shims.

 

[azsoccerpop]

I thought about that and I was building the stand where I could just build the correction in. My concern there was putting any angle that may introduce some instability because the load would be pushing at that angle vs 90*. I am not an engineer so not sure if that would be the case or not. Thanks for the suggestion.



I like the composite route due to the size and weight of the tank. I was going to go with composite shims. Maybe a mix of composite and cedar. Mostly the composite and then fill in with the cedar shims.

I am not a structural engineer but I would think that if you can build the stand to compensate then the force will always transfer down through the corner uprights and that will still be stronger than forcing a perfect rectangle and shimming


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[Lsufan]

I thought the stand was already built. If it is at the point of your last pic then doing what der willie mentioned is a good way to go about it. Build a bottom frame or lay a 2 by flat on the floor & cut the vertical support legs to whatever length they need to be. U may still need to shim in a couple places if the floor isn’t flat. If u are good with a saw u could even cut the bottom frame on angle to match the floor & then all the supports would be cut the same length.

 

[der_wille_zur_macht]

You can get shims that are composite making them waterproof and less likely to compress over time at home depot

I don't mean to pick at your suggestion, but if you're worried about wood (as a material) compressing or getting wet, then the entire stand (made of wood) would be at risk, no?

Composite shims are great, and they're really consistent from one shim to the next. I don't even use cedar shims, I just get cedar shingles - the cheap packs sold as starters. They're basically the same wedge shape but they're much wider and longer than a normal shim, which is great when you have to shim a larger area.

 

[JTL]

I would build the stand to fit or as close as you can get it and then shim a little bit if necessary.

 

[angnak]

Lsufan - yes, it is in that state right now.

Now I am going back and forth again.

What about a combination of basically all of it? Build the stand nice and square. Cut a strip for the bottom of the back to build it up as close to level as possible. Cut some basically big shims for the sides that go in from the back to front. Then finish up by shimming where needed. Kind of building the stand to the floor but flipped from having the legs being cut with an angle to having a large one piece shim, the build up of the bottom of the stand takes that larger gap away and then finish off with the shims.

 

[Lsufan]

I think that would be a good way to go about it. It would be a little easier & faster cutting all the vertical supports the same length. I don’t know how u plan on building the bottom frame, but depending how u build it u could even rip the bottom frame on the angle u need for it to sit on the floor but the top of it still be level. U could also build the bottom frame, then just rip some 2 by material to what u need & place it under the frame. Basically rip a board down the length of the frame. So the whole bottom frame would still be in contact with the floor.

I built my stand pretty close to rocketengineers stand design for my 150. So the bottom frame was built with 2 by 4 turned edgeways with the 1.5” side touching the floor. I knew my floor wasn’t level & when I set the stand in place I soon realized it was going to be very hard to get to the back of it to place any shims. The floor was off around 1/2” altogether but not one corner was level with the other, so I would have had to shim the whole stand except the highest corner. What I did was ripped a 2 by down on the angles I needed & glued & crown stapled that to the bottom of the stand. When I put the stand back in place it was perfectly level & in contact with the floor, so I didn’t have to use any shims at all.

As far as the type of shims, I don’t really have a preference with cedar or composite. It depends what I am using them for. Cedar shims get down to 1/16” & maybe even a little less on the narrow end, so they work good if u are shimming anything less then around 1/8”. Most composite shims are still about 1/8” on the narrow end. So they don’t work well if u are shimming something with less then a 1/8” gap. I do usually use composite if I can.

 

[flsalty]

If you build it correctly you won't need shims. Look up how to build kitchen cabinets to see how to get them level if the floor isn't level. Much better than a bunch of shims.

 

[angnak]

Yea, been looking at scribing kind of the opposite direction. Adding to the bottom instead of taking away from the bottom.

I have the bottom set to be 2x6 but if I go with taking away from the bottom with taking out almost 3/4” off, would everyone recommend going 2x8 or just stick with the 2x6? Top is 2x10. Don’t think I ever stated that.