spedwards Posted March 1, 2006 Share Posted March 1, 2006 I've been thinking about the weight my tank will be pushing and i'm beginning to wonder whether the floor joists / beams are going to hold the weight. With a 5' x 18" x 2.5' tanks, plus 500+ litres of water, stand, hood, substrate, rock work and other various pieces of hardware it's going to weight in between 600 - 700kgs. We are in a single storey pillared house, the tank will be sitting on an exterior wall. I know this should be the strongest place, but I'm worried that I'm going to come home one day to find a fish tank in my garage and a hole in the living room floor What size and weight tanks have others put into a pillared house? Link to comment Share on other sites More sharing options...
Ash Posted March 1, 2006 Share Posted March 1, 2006 I've got a 4x2x2 with big hood, cabinet, etc. But just because I can do it doesn't mean you can (you've got another 100+kg on my setup for one), the standard reply is to seek advice from a structural engineer but I can give you a few tips in the mean time.... Tank orentation. make sure it is sitting across multiple joists. look for the nails in the floorboards & try to have as many rows under the tank as possible. best to have the tank length heading the same way as the floorboards, two joists running the length of the tank isn't as strong as 4 joists running the width. My 4x2 sits on 4 joists. Stand/Cabenet design. Mine has a sheet of 25mm ply as the base with the rest of the structure (also 25mm ply) sitting on top if it. This way there isn't high point loading onto single floorboards for a 50x90mm leg to "punch through" the floor. It helps the floorboards transfer the weight to the joists safer. Near walls is good, mine's on the inside wall of my lounge where the houses centre main support beam runs, so the 4 joists it's sitting on are sitting on the main beam which is sitting on the posts, all dead inline with the back of the tank as would your external wall position mentioned. Basically if your house is in tip-top condition structurally & you put it in the right place you should be fine. That said, what if there is unseen termite damage or something else making the wood weaker than it looks? I'm not trying to tell you just go for it, nor am I saying you can't. It can be done, but you may need to strengthen your house or step down a tank size or two, hell you might be able to make it an extra foot long for all I know! If you are worried about it (which it sounds like you are), consult an engineer first. *Insert usual YMMV type disclaimer here* Link to comment Share on other sites More sharing options...
spedwards Posted March 2, 2006 Author Share Posted March 2, 2006 Thanks for that Ask. After digging around for the building inspection report I have found that the floor structure is made from 50 x 100 and 75 x 100 timbers. There seems to be good support with a weight bearing wall underneath on the opposite side of the room to which I was intending to put the tank. I cannot see the structure directly below when the tank was intended to go as the garage has a covered ceiling. Is is safe to assume that the construction would be the same throughout? The tank weight should be supported by 4 joists. The cabinet will be a Dalbarb, I rang them this morning to confirm that I could take the legs off and have it sitting flat on the floor to disperse weight better and remove any pressure points. I think i might seek expert advice before going any further, there is some other damage that we want a structural engineer to take a look at so this might be just the time! Cheers Jon Link to comment Share on other sites More sharing options...
mark_1 Posted March 2, 2006 Share Posted March 2, 2006 that size joists are easly big enough to suport the weight but it also depends on how far they are spreed if they are between 300-400 intervels they would be able to support a tonne you should have no problems with that weight. Link to comment Share on other sites More sharing options...
spedwards Posted March 2, 2006 Author Share Posted March 2, 2006 They would likley be at the larger side of 300 - 400. I have contacted a couple of engineering companies to get an idea of what the costs will be - will report back when I hear from them. Link to comment Share on other sites More sharing options...
r.d.m Posted March 2, 2006 Share Posted March 2, 2006 ive got a 4x2x2 on yellow tongue particle board with no problems but my 6x2x2 is in the garage on concrete, check with an expert but a couple of tips ,as other people have said spread the load on 25mm ply but also bolt the stand into the wall studs this will stop the inevitable lean forward over time,and absolute leveling is a must,another viable proposition is to get yourself half a dozen lengths of timber the same size as the joists and push or knock them in next to the existing ones,this is called joist sistering and will effectively strenghten the floor for not a lot of outlay Link to comment Share on other sites More sharing options...
spedwards Posted March 2, 2006 Author Share Posted March 2, 2006 another viable proposition is to get yourself half a dozen lengths of timber the same size as the joists and push or knock them in next to the existing ones,this is called joist sistering and will effectively strenghten the floor for not a lot of outlay ← My problem with this is that the floor structure isn't accessible due to the ceiling in the garage space, without pulling the ceiling down. I was thinking some of those expandable supports between the garage slab and the floor structure might work for extra support. How inevitable is the floor sag? Link to comment Share on other sites More sharing options...
bitrusty Posted March 2, 2006 Share Posted March 2, 2006 hi jon i had a 6*2*2 across 5 joists and my floor still bowed.i had a flat bottom and made the stand so that every joist had a leg on it to disperse the weight.i ended up crawling under the house and putting 4*4 joists under each joist with a small concrete pad under that.in my opinion it just aint worth the risk of having that much water come out all over your floor.but in saying that it might not bow in years maybe even ever depends on how solid your house is cheers russ Link to comment Share on other sites More sharing options...
spedwards Posted March 2, 2006 Author Share Posted March 2, 2006 That's definately not the sort of report I wanted to hear! Did it bow towards the centre of the room (ie. away from the tank) or where the tank sat (ie. floor actually sank)? Looks like it might have to go directly over the load bearing wall in the garage, this also has a beam running across the house about 2' from the wall and the tank would sit snuggly between them. It's not the ideal position in the room, but I'm just too worried about the sag factor... Also, got a response from one structural engineering place - $410 for a standard inspection and breif report. Link to comment Share on other sites More sharing options...
gingerbeer Posted March 2, 2006 Share Posted March 2, 2006 Get an engineer is good advice. Running across joists rather than along is sound advice to minimise potential problems. Packing under will stop local punch out of particle board but won't do much to distribute weight -be it ply or particleboard. Foot print will only increase by about twice the thickness of the packing. Near walls is not neccessarily good advise - it depends where the bearers are under and where the load goes to. If it is an outside wall it probably has a bearers under, if it is an internal wall it probably doesn't as probably platform floor. The size joists and bearers listed are for the floor on peirs (1800 mm apart), over the garage will be something else (deep joist to span further - may be a steel beam somewhere too). Taking the legs off will only help if the rest of the cabinet is built to distribut weight evenly. Sistering joists almost doubles the strength of the floor Floors are designed generally for 180 kg point load and 150 kg/m^2 distributed. However most of this weight is to allow for the big party one of event. I would suggest looking for a load of about 60kg max before thinking checking - that is about a standard 4 footer on four legs. (Near a support is much better). (For the engineers who has read the original doc for loads that has the reference to the maximum load from "8-10 dancers dancing hilariously in an 8 foot circle") I have heard of two interesting real cases that have occured recently. One involved a new house with a large rumpus room with a pool table on it. They had a big party and soon afterwards found theat the ceilings downstairs had all cracked. It happened as the weight of the pool table was OK by itself, and the weight of the party was OK by itself, but both together just too much weight for the floor and hence too much vibration/deflection and floor cracked. Outcome owner pays. This hapened in Sydney. The second is not confirmed as true but too good to resist. It involves a 6 foot tank, garage and fathers new BMW. You can join the dots yourselves. The above is general information only and an engineer should be engaged. Steve p.s. get an engineer - they are responsable for what they say until after the day they die - money well spent engagin an engineer I say. Link to comment Share on other sites More sharing options...
spedwards Posted March 2, 2006 Author Share Posted March 2, 2006 The size joists and bearers listed are for the floor on peirs (1800 mm apart), over the garage will be something else (deep joist to span further - may be a steel beam somewhere too). ← It feels like you are saying that I should get an engineer in I do remember seeing "deep joist" in the building report and there is definately a steel beam running across the centre of the garage ceiling. I'm taking a guess that as they have to span a much larger distance the strength would be reduced? The second chance spot is as follows: W W W FFFFFFFFFFFFFFFFFFFFF B B B G G Where: W = Interior Wall F = Floor B = Bearer / Beam G = Garage wall The garage wall is bricked with "pillar style" double brick along the way. The tank would sit neatly between the two bearers. From the way things are sounding, this is the only place i'll be able to put this tank. The other thing is that as it's accessible, the sistering joists idea will be able to be implemented. Based on the tank being 700kgs, with 6 legs i'm looking at 116kgs at each point, I might be able to get extra legs added to try and spread the weight some more (again this depends on the build of the stand). Is it safe to assume that as all the tank weight will be supported by the two bearers in the diagram above and the main section of the room will be supported between the garage wall bearer and the exterior wall bearer that the 8-10 dancers and their circle would be supported by a differenct structure than the tank? Link to comment Share on other sites More sharing options...
mr troph Posted March 2, 2006 Share Posted March 2, 2006 Hi all I just browsed briefly through this topic I have a 6*2*2 get made by a friend with a capacity of about 650lts and asked dad a builder if the floor would support it. His words were no it will go strait threw. The house is about 5 years old on bearers and joists and built by him. I guess you could add extra piers. Lucky I can put it on the pool room slab it should look pretty cool with 40 odd tropheus beside the pool. Link to comment Share on other sites More sharing options...
bitrusty Posted March 2, 2006 Share Posted March 2, 2006 sorry mate yeah my whole floor sank,so i had to jack it up and put piers under each joist so it was kinda like the legs went right through to the ground.was easy for me but it was external wall Link to comment Share on other sites More sharing options...
spedwards Posted March 2, 2006 Author Share Posted March 2, 2006 OK, I just took another look and realised I was a little too keen this morning and that the tank would be over only the garage... Looking more like a no go Link to comment Share on other sites More sharing options...
r.d.m Posted March 2, 2006 Share Posted March 2, 2006 probably your best option is ; 1. go for a 4x2x2 most floors seem happy with these with common sense precautions 2. put the big tank in the garage then do what i did- wait for the next council pick up ,roam the streets and grab a nice armchair (im currently working on the fridge) Link to comment Share on other sites More sharing options...
spedwards Posted March 2, 2006 Author Share Posted March 2, 2006 I like your thinking - problem with your and my area is that you've got to wait until someone requests the pickup before the council comes! Good luck on the fridge, don't expect the door to be on (per council clean up rules) I am now thinking that a more modest tank will be in order. The 5' length is good as it fills the space we have, Dalbarb have a 14" wide by 20" high that would reduce the weight in the vicinity of 300KG over what I was planning. This tank would give about 66KG per leg to hold which is much better, it does half my water volume though (never buy a pillared house!). The big one will have to wait... Link to comment Share on other sites More sharing options...
gingerbeer Posted March 2, 2006 Share Posted March 2, 2006 Jon, $410 is pretty cheap. Steve Link to comment Share on other sites More sharing options...
mark_1 Posted March 2, 2006 Share Posted March 2, 2006 how old is the house because if it is a few years old they might have use the new hi beam that looks like a steal i beam if you have these the floor will support a 4x2x2. if a house could not support this weight im sure somthing is fairly dodgy about it or maybe the joists were fairly poor graded. im no structual engineer but iv worked and stood house frames before and they should hold the weight. but when talking about a 6x2x2 thats understandable about a standed bearer and joist house not able to support the weight but a new house would be able to support the weight because of all the new frame laws comming in, and that all the builders are turnig to the new hi beams which are much stronger than the old solid beam and dont twist and bow. Link to comment Share on other sites More sharing options...
spedwards Posted March 2, 2006 Author Share Posted March 2, 2006 $410 is pretty cheap. ← I don't doubt that, but for what it's worth to have the garage ceiling pulled apart to be told the answer that I'm pretty sure will be the one given I'd rather put that money towards getting something a little smaller and be done with it. We'll probably get them (or someone similar) out to check out the other problem anyways. Link to comment Share on other sites More sharing options...
spedwards Posted March 2, 2006 Author Share Posted March 2, 2006 how old is the house ← The house is 30 years old, we're probably lucky it's still standing Link to comment Share on other sites More sharing options...
mark_1 Posted March 2, 2006 Share Posted March 2, 2006 go for like a 4x18x2 still a good sized tank but weighs much less and this tank you wont have to worry about getting a structual engineer in that might cost the same as getting the 4x2x2 Link to comment Share on other sites More sharing options...
spedwards Posted March 2, 2006 Author Share Posted March 2, 2006 go for like a 4x18x2 ← Thanks mate, I'll think about it. Only about 60KG heavier than what I'm currently thinking. Link to comment Share on other sites More sharing options...
mark_1 Posted March 2, 2006 Share Posted March 2, 2006 that 60kg could make all the difference Link to comment Share on other sites More sharing options...
spedwards Posted March 2, 2006 Author Share Posted March 2, 2006 It was the nicest way I could think to say "Thanks, but no thanks" Link to comment Share on other sites More sharing options...
gingerbeer Posted March 2, 2006 Share Posted March 2, 2006 The two examples I gave both used engineered timber products (generic term for I-beams and webbed joists) - 4*2*2 = 450 L + ornaments - on 4 legs 110ish kg 6*2*2 = 650 L + ornaments - on 6 legs 130ish kg 4*18*2= 350 L + ornaments - on 4 legs 90ish kg Jon - it may be a go for the big tank and there are people with big tanks on timber floors - but once beyond a standard four footer - ya gotta be careful. What new frame laws Mark? Last major change I know off was 1999 - decreased spans of joists. (and removed need for solid blocking to solid joists) Next change to be released with next AS4440 will be about battens on Girder trusses with sheet roof (may alreaddy be released - will have to double check tommorrow). Steve Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.