Can my floor support a 375 Gallon tank?

[skjl47]

Will be on the corner of 2 outside walls

Hello; That is about as good a place as you can get on a wood floor with joists. That may reduce the number extra supports needed.
That narrow crawl space and the heating ducts will make the job hard.
I would try to "box" and/or "sister" the joists where it my floor, but the heating duct may get in the way.
Again if those last two terms are not familiar to you, get a professional. This is not the sort of DIY project to start with.

 

[brendon7358]

Where the tank will be will be pretty easy to access. That's the reason I will be putting it there. There won't be any ducts in the way, the only thing is a small pipe. Picture below, tank will be in that corner.

 

[DN328]

The pictures you posted shows a sufficient room to work. Not ideal, but achievable if you decide to pursue.

As reference, I had a need to do something similar for my setup for about over 300 gallons of water tank/sump, steal sand and all things related to a setup.

Original, tanks sits on the beam. I added two more on both sides because I was paranoid. Seen in the second picture. I have dirt/pebble ground so used concrete platform.

 

[brendon7358]

The pictures you posted shows a sufficient room to work. Not ideal, but achievable if you decide to pursue.

As reference, I had a need to do something similar for my setup for about over 300 gallons of water tank/sump, steal sand and all things related to a setup.

Original, tanks sits on the beam. I added two more on both sides because I was paranoid. Seen in the second picture. I have dirt/pebble ground so used concrete platform.
View attachment 1267069 View attachment 1267070

How did you get it in there tightly?

 

[DN328]

How did you get it in there tightly?

With the help of another person, I carried down all the cement blocks through a standard crawl space door/opening. The two 8' long 4"x8" beams barely fit through the crawl space air vents (that typically surrounds the house). You can barely see one in the first picture on the top right, where there is light shining through. I cut one of the netted vents and slid the beams through. I've since replaced the cover to keep things from crawling in.

We are basically working on our knees, sitting and crawling around. The 4x4 cuts were in the crawl space once we got things measured out. It wasn't fun, just take a brakes in between.

From the pictures does it look like we have the same vertical space?

 

[skjl47]

Hello; If you decide to go the DIY route bear this in mind. When a home is built the footers are usually dug deep enough to be below a freeze zone (frost depth) for the area. How deep depends on where you are and how cold it gets over winter. This is code and is known.

What the last pictures show are cement bases placed on the ground and likely well above the frost heave zone. This may not be much of an issue because the ground in a crawl space is normally protected from such freezing. The braces pictured are well spaced and look to be more than enough to carry the load. Frost heave may never be a problem.

What can be a potential problem with such a way to set braces is the dirt itself. That being is it compacted dirt or is it fill dirt. Fill dirt can be where a hole was dug too deep for a house and some was put back in or say the dirt dug out for the foundation footers is dumped into the crawl space. Fill dirt can settle which is why I suggested in an earlier post to consider some sort of adjustable bracing.
If you are lucky the dirt is compacted. Say the soil where the house now sits was undisturbed for decades of longer. Over those many years it becomes settled and compacted. You can remove a few feet of it to level out a spot and as long as no fill is put back you will still have surface below which is nicely compacted. Compacted soil supports a load with much less settling. It is my understanding a good foundation contractor tries to put the footers on compacted ground.

 

[DN328]

Hello; If you decide to go the DIY route bear this in mind. When a home is built the footers are usually dug deep enough to be below a freeze zone (frost depth) for the area. How deep depends on where you are and how cold it gets over winter. This is code and is known.

What the last pictures show are cement bases placed on the ground and likely well above the frost heave zone. This may not be much of an issue because the ground in a crawl space is normally protected from such freezing. The braces pictured are well spaced and look to be more than enough to carry the load. Frost heave may never be a problem.

What can be a potential problem with such a way to set braces is the dirt itself. That being is it compacted dirt or is it fill dirt. Fill dirt can be where a hole was dug too deep for a house and some was put back in or say the dirt dug out for the foundation footers is dumped into the crawl space. Fill dirt can settle which is why I suggested in an earlier post to consider some sort of adjustable bracing.
If you are lucky the dirt is compacted. Say the soil where the house now sits was undisturbed for decades of longer. Over those many years it becomes settled and compacted. You can remove a few feet of it to level out a spot and as long as no fill is put back you will still have surface below which is nicely compacted. Compacted soil supports a load with much less settling. It is my understanding a good foundation contractor tries to put the footers on compacted ground.

If you were referring to my picture, we basically placed the concrete on the pebbles as to how the builder placed the cement pad for the original beam that can be seen. They did use a larger diameter to distribute the weight I assume.

Ive gone down a few times since the tank was set up and by all accounts the cement pads remain as is as far as I can tell.

 

[skjl47]

If you were referring to my picture, we basically placed the concrete on the pebbles as to how the builder placed the cement pad for the original beam that can be seen.

Hello; Yes I think I was referring to your photos. That setup looks good and quite sturdy. Good that the pillars have not settled.
So if you copied what the constructor did for the house footers, that is put a cement pad on pebbles. Also that you did so at the same depth in the soil as the contractor, then you should be good in terms of a frost heave. My guess being you are in a mild winter climate area.
Here in northern Tennessee I think the footers need to be down around 24 inches.
Although some folks go much more shallow.
I recall back in 1977 and 1978 how folks who did not bury their water lines so deep had them freeze. They had gotten away with it for many years, but it caught up with them those winters. One way we tried to thaw the galvanized lines out was to dig two holes to expose the metal pipe and hook up a DC welder.
Also lots of cars and diesel trucks had their fuel lines freeze up. I had already been in the habit of keeping over a half tank of fuel in my tanks at the minimum and tried to keep them close to full in the winter. That way the metal tanks would have less air volume to "sweat" ( condensation) on the inside and thus build up water in the tanks. I also used some alcohol additives. Lots of stranded cars. Not sure the issue is such a problem now days with the plastic tanks and the better closed fuel systems. Also a lot of fuel already has alcohol in it.

In areas even further north footers may need to go even deeper than 24 inches.

 

[millerkid519]

Standard in Ontario is 4 feet

 

[skjl47]

Hello; After thinking about it I felt the issue of frost heave should be put in perspective. It is not very likely at all to be an issue in a crawl space of a heated house. Might be if the power and heat were off for a long time in a bitter cold spell. Even then in a closed off crawl space not likely a big deal. Sorry for leading comments down that path.

The more likely among my comments will be the possibility of settling over time.