Is This Stand Design Safe? (Not your normal stand design question)

gilweb · 08/06/2009, 08:21 PM

I am installing an inwall setup and there is a lip from the concrete floor and to where the actuall wall is. It is hard to explain. The lip is wood and I dont think it can hold the wieght. I was thinking about making the stand like this to avoid taking the chance that the wood floor can hold its part of the weight.

Please let me know what you think. I know the stand itself needs more bracing but I am asking about the canterleavered part I designed. The tank is 72Lx30Dx24H. The top of the stand would be 30D but the botton would be 24D.

Please let me know your thoughts.

trwells · 08/06/2009, 10:04 PM

The spanned board (under the top sheet of plywood) should run the length of the plywood. Is there any reason the front "legs" or vertical supports can't be studs in the wall itself?

Post pictures and you will get more comments.

james3370 · 08/06/2009, 10:05 PM

is the "canterleavered part" the part going against the wall?? can't speak to if the triangle pieces will support the weight of the overhang or not, but my 1st thought was if it is going up against the wall, is there any way you can tie it into the existing wall framing?

think i'll divert the structural advice/opinions to the pros LOL

gilweb · 08/07/2009, 06:10 AM

The canterleaverd part will be against the wall. In these pictures you will see what I am talking about. Half of the garage was converted into a den so there is a "step up" of wood where the new den floor is.

I hope the pictures clear up why im thinking of building it this way.

Mark426 · 08/07/2009, 06:18 AM

You let the wall structure support the front lip of your stand, NOT the triangle pieces.

gilweb · 08/07/2009, 06:21 AM

I would normaly agree. But I did not build the den floor so I am not 100% sure it can support the weight. That is how I came to this idea.

trwells · 08/07/2009, 11:41 AM

Is it possible to tell what is behind the bottom 2x running on top of the shims on the concrete? If there are more 2xs running in the same manner then it should be quite strong. I see what you mean though because if someone only used the one then the only thing supporting the inside portion of the wall is the floor itself in bending.

The weak link of your drawing is the cantilever as you are aware. Because the sides of the front length span is not supported it will not bow down in the middle of the front span like a normal stand. Rather the entire front will "curl" downwards. You need to add strength in bending. The wedges are not a good solution when better options exist.

You should build the top "frame" to the dimensions of the tank/top plywood (72x30x24) using several spanning pieces from front to back. Be sure to leave room for the overflow plumbing. Build the front of it into the wall as suggested. Then place some support legs just off the wall on the concrete. Place the vertical supports in the wall directly over the "wood shims" on the concrete (not to the front not to the side). If not possible put in some wood shims under the vertical supports. No "gaps" from tank to floor on the vertical supports in the wall. It is hard to tell what is behind the spanning 2x on the floor, so you can better decide exactly how to do it.

I hope this makes some sort of sense and is some kind of helpful.

Keep asking and people will jump in once someone says something they disagree with. You need controversy to get responses.

Perhaps I have provided that.

gilweb · 08/07/2009, 12:04 PM

trwells, I appreciate the well thought out response. I see exactly what you are saying. I will make the top frame the full size of the tank. When I get home I will see if there are more 2x's in the back. Hopefully there will be.

Thanks,
Gil

MattShack · 08/07/2009, 12:19 PM

trwells has the best solution.

If you're only going to can cantilever into the wall 3 1/2" (stud thickness), then you could do it if the "joist" under the stand are thick enough. But it needs to be built like trwells suggested as one piece and not with the triangles.

If it were me, I would build the top as suggested above and cut each 2x4 stud to about 3" shorter than the bottom of the support frame "joist" of your stand. I would install a double top plate which would be the 3" difference and slide the cantilevered part of the stand onto the top of your double top plate and you will have full support.

It would be exactally as the wall should be built now. If you look to the top of your cut out, it should have a double top plate. Kinda like I built this stand except the front will be your existing wall cut down to the right height so the joist can sit on top.

JTL · 08/07/2009, 01:01 PM

A normal cantilever is just running your 2x6"s over the beam (the 2x6 that the bottom of the triangles are fastened to) so they extend to the edge of the plywood. Ditch the triangles. You can fill in the spaces between the 2x6's if you want. It would help to keep them from shifting side to side. You have very small cantilever and the triangle pieces would probably work fine, but it would be more work to cut and install those that just doing it the traditional way. Just me opinion as DIYer, not an engineer.

haps · 08/07/2009, 01:23 PM

Quick calculation based on your dimensions shows a capacity around 224 gallons. Water is 8lbs per gallon which means water weight of 1792lbs, add 500lbs for the tank and you have around 2300lbs to support. Four wood vertical supports isn't enough(imo). They would support 573lbs(without a 2x safety factor) each with the legs toward the cantiliever support a fuzz more than the other two. Summation: Put many more vertical supports in your framework.

gilweb · 08/07/2009, 01:24 PM

Haps, This was in the original post;

"Please let me know what you think. I know the stand itself needs more bracing but I am asking about the cantilevered part I designed."

I do appreciate the input however!

haps · 08/07/2009, 01:29 PM

Didn't know what part of the "stand" you meant. The cantilevered part looks fine as long as you provide additional support to that side going to the floor.

NanoReefWanabe · 08/07/2009, 02:05 PM

i agree that the cantilever will be fine...you are allowed 1/3 the joist length to be cantilevered without issue...if your cantilever is only half of that i think it will be fine provided the members are sized correctly...you have 2x6 shown which should be fine...as mentioned the triangle pieces will provide no additional support to the stand, they can only be attached via fasteners (and one should never rely on fasteners to hold a shear load)...i cant imagine the floor of you garage would crack under the weight of your tank...most trucks weight twice your tank and dont crack garage floors...

also by the looks from the pictures i would have to assume the "builder" that did the room placed the floor on what looks like 3/4ply shims to keep water from the garage and moisture from underneth from wrecking the floor ( an air/ drainage space under the floor...hopefully there is some sort of polyethylene vapour barrier between the strapping concrete floor...i honestly dont think you will have any problems using the wall and studs to support your tank

uncleof6 · 08/07/2009, 02:43 PM

Quote:

Originally posted by trwells

Keep asking and people will jump in once someone says something they disagree with. You need controversy to get responses.

Perhaps I have provided that.

Maybe, but then we just might sit back, give our brains a rest and laugh.......

J

MikeTV1 · 08/07/2009, 03:00 PM

Can't you just drill through that bottom stud and see if you run out of wood after 1.5"? That would tell you if that bottom is a single or double 2x4 and if it would support the weight. You can then add how ever many verticals you think you need between the existing studs.

trwells · 08/07/2009, 03:08 PM

Quote:

Maybe, but then we just might sit back, give our brains a rest and laugh.......

That could be true for people who have self control, but is there ever a shortage of people who don't?

gilweb · 08/07/2009, 08:24 PM

OK, How does this look?

trwells · 08/07/2009, 08:35 PM

Like it could hold a tank. You really don't need that many vertical boards across the front, but if it helps you sleep at night then do it.

It is hard to see if you have any additional front to back boards spanning under the length of the plywood at top, but you do on the bottom of the frame, so I assume the top has the same design?

The only thing that needs to be changed is the front length span should be supported at the ends. Just cut the two boards on the side back a bit so the front board fills the corners and rests on the vertical legs.

gilweb · 08/07/2009, 08:56 PM

Yes, I have the same boards spanning under the top plywood. I actually have 2 more than the bottom. I did draw that front beam wrong but when I build it I will make sure it is all the way across the front.

Thanks for all the help!

BeanAnimal · 08/08/2009, 04:36 AM

Way overbuilt evev to my standards... That is half a forest there!

As for supporting the bottom of the tank. You did not mention if it was a trimmed glass, flat bottom (no trim) glass or Acrylic tank. If it is a trimmed tank, then the only support needed is around the perimeter of the tank. A single center cross member can help prevent the front and rear rails from twisting.

If it were me, I would Build a 2x6 frame to rest the tank on. Add back legs and let the front sit right on the wall studs. 1/10 the work and still plenty strong enough to park a car on. If you can't sleep with it resting on the wall studs, then simply add front legs right behind the wall studs. You don't need to mess with crazy cantilever supports for 4"-5" of overhang, even if the top frame was just 2x4 skinned with plywood.

08/06/2009, 08:21 PM	#1
gilweb Registered Member Join Date: Dec 2001 Location: Long Island Posts: 334	Is This Stand Design Safe? (Not your normal stand design question) I am installing an inwall setup and there is a lip from the concrete floor and to where the actuall wall is. It is hard to explain. The lip is wood and I dont think it can hold the wieght. I was thinking about making the stand like this to avoid taking the chance that the wood floor can hold its part of the weight. Please let me know what you think. I know the stand itself needs more bracing but I am asking about the canterleavered part I designed. The tank is 72Lx30Dx24H. The top of the stand would be 30D but the botton would be 24D. Please let me know your thoughts. Last edited by gilweb; 08/06/2009 at 08:27 PM.

08/06/2009, 10:04 PM	#2
trwells Registered Member Join Date: Dec 2006 Location: Lubbock, Tx Posts: 248	The spanned board (under the top sheet of plywood) should run the length of the plywood. Is there any reason the front "legs" or vertical supports can't be studs in the wall itself? Post pictures and you will get more comments. __________________ "I owe my success to having listened respectfully to the very best advice, and then going away and doing the exact opposite." - G. K. Chesterton Current Tank Info: 39 gallon CAD Lights

08/06/2009, 10:05 PM	#3
james3370 Registered Member Join Date: Aug 2008 Location: US ARMY - El Paso TX Posts: 3,678	is the "canterleavered part" the part going against the wall?? can't speak to if the triangle pieces will support the weight of the overhang or not, but my 1st thought was if it is going up against the wall, is there any way you can tie it into the existing wall framing? think i'll divert the structural advice/opinions to the pros LOL __________________ Yes I hear voices in my head, but they speak spanish so I can't understand anything they say. there's no place like 127.0.0.1 It's a shame that stupidity isn't painful.... Current Tank Info: currently tankless....but planning an AIO

08/07/2009, 11:41 AM	#7
trwells Registered Member Join Date: Dec 2006 Location: Lubbock, Tx Posts: 248	Is it possible to tell what is behind the bottom 2x running on top of the shims on the concrete? If there are more 2xs running in the same manner then it should be quite strong. I see what you mean though because if someone only used the one then the only thing supporting the inside portion of the wall is the floor itself in bending. The weak link of your drawing is the cantilever as you are aware. Because the sides of the front length span is not supported it will not bow down in the middle of the front span like a normal stand. Rather the entire front will "curl" downwards. You need to add strength in bending. The wedges are not a good solution when better options exist. You should build the top "frame" to the dimensions of the tank/top plywood (72x30x24) using several spanning pieces from front to back. Be sure to leave room for the overflow plumbing. Build the front of it into the wall as suggested. Then place some support legs just off the wall on the concrete. Place the vertical supports in the wall directly over the "wood shims" on the concrete (not to the front not to the side). If not possible put in some wood shims under the vertical supports. No "gaps" from tank to floor on the vertical supports in the wall. It is hard to tell what is behind the spanning 2x on the floor, so you can better decide exactly how to do it. I hope this makes some sort of sense and is some kind of helpful. Keep asking and people will jump in once someone says something they disagree with. You need controversy to get responses. Perhaps I have provided that. __________________ "I owe my success to having listened respectfully to the very best advice, and then going away and doing the exact opposite." - G. K. Chesterton Current Tank Info: 39 gallon CAD Lights

08/07/2009, 12:19 PM	#9
MattShack Registered Member Join Date: Aug 2008 Location: Ridgeland, MS Posts: 1,187	trwells has the best solution. If you're only going to can cantilever into the wall 3 1/2" (stud thickness), then you could do it if the "joist" under the stand are thick enough. But it needs to be built like trwells suggested as one piece and not with the triangles. If it were me, I would build the top as suggested above and cut each 2x4 stud to about 3" shorter than the bottom of the support frame "joist" of your stand. I would install a double top plate which would be the 3" difference and slide the cantilevered part of the stand onto the top of your double top plate and you will have full support. It would be exactally as the wall should be built now. If you look to the top of your cut out, it should have a double top plate. Kinda like I built this stand except the front will be your existing wall cut down to the right height so the joist can sit on top. __________________ Matt S Current Tank Info: 1000 gallon display - 500 gallon sump - 75 gallon fuge

08/07/2009, 06:10 AM	#4
gilweb Registered Member Join Date: Dec 2001 Location: Long Island Posts: 334	The canterleaverd part will be against the wall. In these pictures you will see what I am talking about. Half of the garage was converted into a den so there is a "step up" of wood where the new den floor is. I hope the pictures clear up why im thinking of building it this way.

08/07/2009, 06:18 AM	#5
Mark426 Registered Member Join Date: Dec 2005 Location: South Carolina Posts: 2,479	You let the wall structure support the front lip of your stand, NOT the triangle pieces.

08/07/2009, 06:21 AM	#6
gilweb Registered Member Join Date: Dec 2001 Location: Long Island Posts: 334	I would normaly agree. But I did not build the den floor so I am not 100% sure it can support the weight. That is how I came to this idea.

08/07/2009, 12:04 PM	#8
gilweb Registered Member Join Date: Dec 2001 Location: Long Island Posts: 334	trwells, I appreciate the well thought out response. I see exactly what you are saying. I will make the top frame the full size of the tank. When I get home I will see if there are more 2x's in the back. Hopefully there will be. Thanks, Gil

08/07/2009, 01:01 PM	#10
JTL Registered Member Join Date: Jun 2003 Location: Venice Island, FL Posts: 2,532	A normal cantilever is just running your 2x6"s over the beam (the 2x6 that the bottom of the triangles are fastened to) so they extend to the edge of the plywood. Ditch the triangles. You can fill in the spaces between the 2x6's if you want. It would help to keep them from shifting side to side. You have very small cantilever and the triangle pieces would probably work fine, but it would be more work to cut and install those that just doing it the traditional way. Just me opinion as DIYer, not an engineer. __________________ John 100 gallon DT and 50 gallon sump with refugium. Reefbreeders Photon V2+.

08/07/2009, 01:23 PM	#11
haps Registered Member Join Date: Mar 2009 Location: St. Louis Missouri.....ish Posts: 11	Quick calculation based on your dimensions shows a capacity around 224 gallons. Water is 8lbs per gallon which means water weight of 1792lbs, add 500lbs for the tank and you have around 2300lbs to support. Four wood vertical supports isn't enough(imo). They would support 573lbs(without a 2x safety factor) each with the legs toward the cantiliever support a fuzz more than the other two. Summation: Put many more vertical supports in your framework.

08/07/2009, 01:24 PM	#12
gilweb Registered Member Join Date: Dec 2001 Location: Long Island Posts: 334	Haps, This was in the original post; "Please let me know what you think. I know the stand itself needs more bracing but I am asking about the cantilevered part I designed." I do appreciate the input however!

08/07/2009, 01:29 PM	#13
haps Registered Member Join Date: Mar 2009 Location: St. Louis Missouri.....ish Posts: 11	Didn't know what part of the "stand" you meant. The cantilevered part looks fine as long as you provide additional support to that side going to the floor.

08/07/2009, 02:05 PM	#14
NanoReefWanabe Registered Member Join Date: Oct 2006 Location: Barrie, Ontario, Canada Posts: 6,639	i agree that the cantilever will be fine...you are allowed 1/3 the joist length to be cantilevered without issue...if your cantilever is only half of that i think it will be fine provided the members are sized correctly...you have 2x6 shown which should be fine...as mentioned the triangle pieces will provide no additional support to the stand, they can only be attached via fasteners (and one should never rely on fasteners to hold a shear load)...i cant imagine the floor of you garage would crack under the weight of your tank...most trucks weight twice your tank and dont crack garage floors... also by the looks from the pictures i would have to assume the "builder" that did the room placed the floor on what looks like 3/4ply shims to keep water from the garage and moisture from underneth from wrecking the floor ( an air/ drainage space under the floor...hopefully there is some sort of polyethylene vapour barrier between the strapping concrete floor...i honestly dont think you will have any problems using the wall and studs to support your tank

08/07/2009, 03:00 PM	#16
MikeTV1 Registered Member Join Date: May 2002 Location: Stillwater Posts: 150	Can't you just drill through that bottom stud and see if you run out of wood after 1.5"? That would tell you if that bottom is a single or double 2x4 and if it would support the weight. You can then add how ever many verticals you think you need between the existing studs.

08/07/2009, 08:24 PM	#18
gilweb Registered Member Join Date: Dec 2001 Location: Long Island Posts: 334	Revised OK, How does this look?

08/07/2009, 08:35 PM	#19
trwells Registered Member Join Date: Dec 2006 Location: Lubbock, Tx Posts: 248	Like it could hold a tank. You really don't need that many vertical boards across the front, but if it helps you sleep at night then do it. It is hard to see if you have any additional front to back boards spanning under the length of the plywood at top, but you do on the bottom of the frame, so I assume the top has the same design? The only thing that needs to be changed is the front length span should be supported at the ends. Just cut the two boards on the side back a bit so the front board fills the corners and rests on the vertical legs. __________________ "I owe my success to having listened respectfully to the very best advice, and then going away and doing the exact opposite." - G. K. Chesterton Current Tank Info: 39 gallon CAD Lights

08/07/2009, 08:56 PM	#20
gilweb Registered Member Join Date: Dec 2001 Location: Long Island Posts: 334	Yes, I have the same boards spanning under the top plywood. I actually have 2 more than the bottom. I did draw that front beam wrong but when I build it I will make sure it is all the way across the front. Thanks for all the help!

08/08/2009, 04:36 AM	#21
BeanAnimal Registered Member Join Date: Feb 2003 Location: Pittsburgh Posts: 20,772	Way overbuilt evev to my standards... That is half a forest there! As for supporting the bottom of the tank. You did not mention if it was a trimmed glass, flat bottom (no trim) glass or Acrylic tank. If it is a trimmed tank, then the only support needed is around the perimeter of the tank. A single center cross member can help prevent the front and rear rails from twisting. If it were me, I would Build a 2x6 frame to rest the tank on. Add back legs and let the front sit right on the wall studs. 1/10 the work and still plenty strong enough to park a car on. If you can't sleep with it resting on the wall studs, then simply add front legs right behind the wall studs. You don't need to mess with crazy cantilever supports for 4"-5" of overhang, even if the top frame was just 2x4 skinned with plywood.