Basement reinfocement

[Coleus]

Ok i need all your expertise helps here, I need to put a 135 gallon tank (120''x20''x13'') between two floor joints. there are no support beam anywhere near them except for the concrete wall, which is 1.8 feet away from the tank and is perpendicular to the two joints.

So, putting an underneath beam that is perpendicular to two joints is not possible. Putting a beam between 2 joints and parallels to them also not possible because of the floor plan.

My question is : If i put a support beam that is diagonal between 4 joints (the tank is in middle of these 4 joints). Will that works or is it useless? Or sistering floor joints is good enough?

Thanks

[wingedfish]

Diagonal is better than nothing. I have 100 gallons of water on an outside wall in the middle of a 14' span, parallel to 10" joists (only 2 under it). If I bounce in front of the tank I can get some impressive wave action.

[gregzz4]

There must be at least one civil engineer around here.

I'd suggest you make up a drawing of your joists with their length from wall to wall, and the position of the tank.
Even a picture of a drawing will do.

[Myka]

How old is this house? What type or finished flooring will the tank be sitting on? If the house is fairly new, say less than 20 years old, and doesn't have tile under it then I don't think you need to reinforce at all. If the tank was 4' long and that volume then maybe, but spread over 10' I don't think will be an issue.

[steve fedyk]

Double the floor joist and you shouldn't have any problems. Run them the full length from wall to wall.

[Coleus]

Thanks for everyone inputs. The house is 7 years old and it has title on the top floor.

I guess picture will illustrate better so I draw some sketches. as you can see in the sketch

The yellow blocks is what i intend to do. I can do sistering joints but i think this probably better than sistering. What do you think?



Cheers

[Coleus]

Originally Posted by steve fedyk

Double the floor joist and you shouldn't have any problems. Run them the full length from wall to wall.

The distance between the LVL and wall is much longer than in the sketch. Also there are all kind of water pipes and heating ducts between those joins so running more joins won't be an option.

[hillegom]

How long is the yellow, diagonal beam you will put in?
I think that is a good idea, but length matters. And then, depending on the length, the depth of the diagonal has to be deep enough to carry the weight.
Probably two 2x8s
But I am guessing at this point. There are tables for that info

[StirCrazy]

Originally Posted by Coleus

Cheers

what is the space under where you want to put the tank. problem is especialy with tile any deflection will crack the grout and possibly tiles. adding a tank they will realy increase the movment in the joists.

what is the distance from the foundation wall to the wall with the green posts?

if the space under the tank isn't used for anything I would be trmpted to run one or two beams (depending on the span) parallel to the foundation wall to stiffin it right up and minimize any chance of deflection. this may be overkill but better to do it that way then not good enough.

of course this would take 4, 2X10s and 4 jack posts but if the space below the tank isn't use for anything then it is still a fairly cheep option.

weather you need one set or two would depend on the span from the foundation wall to the LVL beam.

Steve

[sphelps]

Be warned that adding jack posts at random on a basement slab could do more harm than good. Typical basement support posts are placed on pre planned piles to minimize effects from ground expansion. Other areas in the basement don't offer such protection, in you put in a post and jam it tight any movement from the basement slab will transfer to the main floor. The seriousness of it depends on the soil conditions and the foundation but if you have cracks in your slab it's a good sign not to add such support posts.

Best option I think would be to add a beam from green post to green post if possible, however there must be support there already even if it's down the line further. So it's possible you're over thinking this, if your sub-floor is decent which it would be if it tile or hardwood then 135 gallons would probably be fine without concern. Perhaps relocating the sump would be a good idea to reduce the load but I really don't see a huge threat.