Pole Barn vehical service trench construction?

SPIKER · Feb 28, 2004

hi Av8ter:

thanks for the input:

today I was looking again at the barn setup. right now the biggest problem is where to put the pit in the barn. the barn is 36' wide and has posts on 10' ctrs down the middle. the 9' door is centered on the left side. I don't have any way of digging the dirt using my tractor mounted back hoe and then getting the dirt into a dump to get out side. as the back hoe does not swing around to the side far enough to dump into the trailer. that means putting the pit sideways in the barn for easy dumping and that will also let the barn still to be used for storage in the mean time while the floor work is going on. (I ordered all the infloor radiant stuff yesterday form tek supply http:www.tek-supply.com ) almost 3 grand for the infloor tube fittings and bubble foil / moisture barrier stuff but I ordered enough to do the 10 lean too and the extra for a 2nd project.)

anyhow I'm thinking it will be the easiest way and when I start the pit and footers, I'm going to pour them as well as footers for "I" beams so I can remove one center 6x6 post and replace it with a beam set between the remaining posts and NEW footers I'll pour. (have to support the 2nd floor with jacks while the 6x6 is removed and the steel I beam installed.) not a problem and then the access for the pit would be much easier.

the last resourt is a new small additional 2 car garage outside increase the roof height on one bay for lift. cost wise I would end up in the 10K range that way by the time I add building & lift if not more. so that means I could farm out the pit install for about the same price....

ok nuf thinking. too late for that.

Mark /forums/images/graemlins/ooo.gif

TBAR · Mar 1, 2004

Are you sure you don't want to do an over head crane. Here is a picture of my DIY crane in a pole shed. (Yes I had an engineer do the numbers for me) It is not very tall but it gets the job done.

http://community.webshots.com/photo/43399132/120093970vglLnm

http://community.webshots.com/photo/43399132/120093717FGQrEo

http://community.webshots.com/photo/43399132/120093513uSPTjf

TBAR

SPIKER · Mar 1, 2004

I think I'll be putting in some I beams for service work too! but still don't have the height to lift the cars up to get under them. so a pit gets me under and a I beam gets the engines out from above.! now that is a better combo! /forums/images/graemlins/smile.gif

I ordered all the PEX-AL-PEX and the FOIL-BUBBLE-BUBBLE-PLASTIC and fittings this past week. cost me 2700 for that delivered this week. next items are pumps, valving and a water jacketed wood stove which I'll build myself this summer. (PRAYING S.S. prices drop and don't get so high as that 30% prediction.!)

Mark M /forums/images/graemlins/smile.gif

SPIKER · Mar 12, 2004

bumping up
BUMP /forums/images/graemlins/smile.gif

LBrown59 · Dec 12, 2004

( Mark,
What did cross my mind was if it would effect your homeowners insurance. In my state you are not allow to have a service pit any longer. Even if you do not have to go through the inspection process the insurance company still expects you to meet current code on any structure. Of course that means if you don't…… they have an out on a claim if you ever had to make one. Might be something to check.

MarkV
) They could also simply cancel your current policy.

That's what all insurance companies do if you have A trampoline.

They might do the same with a pit.

tomrscott · Jan 1, 2005

I bought a place with a 1600sqft pole garage/workshop that already has a large pit. I think it's about 6' deep and 22' long, maybe 5' wide. It has steel channels recessed along the top edge about 3.5" (just right for a 4x4) so you can easily put a cover over it. I am not worried about how strong it is, the guy who built this place way over built everything (partly why I bought the place).

He did point out several things worth noting. Ventilation has already been mentioned. But you also want to consider explosion proof low voltage, low current lighting. AC can can be an explosion hazzard with the propensity for fumes to accumulate, even with ventilation. Doesn't hurt to be safe. I think the bathroom fan is a real good idea too. He plumbed in some 4x4 electric boxes. I thought I would run some low voltage outdoor yard lighting through the conduit. He also put a drain trench about six inches wide and six inches deep at the bottom, and dug a french drain to it that runs way out into the pasture. For oil changes. I've got a 55gal drum in the trench and a pipe with a funnel on top. The roof truss assembly is supposed to be stout enough to lift a whole truck, so lifting the full drum out to recycle it shouldn't be a problem, but I haven't used it much yet. I know that he lifted out a V8 engine once with it. It is clearly very strong. I need to add steps at the ends, just using step ladder and it's a nuisance.

AndyMA · Jan 2, 2005

( AC can can be an explosion hazzard with the propensity for fumes to accumulate, even with ventilation. Doesn't hurt to be safe. I think the bathroom fan is a real good idea too. He plumbed in some 4x4 electric boxes. I thought I would run some low voltage outdoor yard lighting through the conduit. )

As far as explosion hazzard, it's not going ot matter one bit if the spark that ignites that explosion is from low or hig voltage, AC or DC. The best method is to keep all switches outside of the pit. Also be especially careful of motors, any that use brushes spark. On another note, be careful of electrical tool use. Air tools are safer, although they can still create sparks. Overall I would just make sure that the pit is properly vently from an large external fan and explosive vapors will never build up.

Andy

Andy

tomrscott · Jan 2, 2005

Higher voltage will arc more easily across a wider air gap than lower voltage. It is not impossible to generate an arc with low voltage, but it is much less likely.

Ever notice how long the insulators are on high voltage distribution towers, compared to the smaller insulators on your neighborhood telephone pole? The difference is the amount of voltage they carry. Higher voltage arcs across a wider insulating air gap. Or for another example, there is no such thing as low voltage lightning.

It is not possible to keep all electrical sources outside the pit, you are going to need light down there. A dropped 120V AC work light can set off quite an explosion if there are any fumes, but a dropped 12V malibu light will be far less likely to (by just about a factor of 10).

Higher voltage will generate an arc across a larger air gap, meaning it is a greater risk of arc.

Now someone is going to point out that you can make quite an arc across a car battery, and that is true, but you have to give it a good conductive path and the size of the arc is due to the tremendous low-impedance current capacity of a battery. The fact remains that it won't jump through as much air gap as 120V, so it is still less likely to create an arc.

If you snap a small rocker switch or unscrew a bulb from a live 120V socket it is a lot more likely to sizzle with arc a bit as you unscrew it, than a taillight bulb from your car. Safer yet is a 3V flashlight bulb.

It is a matter of reducing risk. Lower voltage is safer than higher voltage.

A good friend is an eletronic design engineer (I also have 25 years as an electronics designer) who designs computer control system networks for oil refineries and chemical factories. They are so concerned about explosion risk that they reduce the voltage even lower than standard computer networks, from 5V down to the milivolt range.

I think 12V malibu lights would be a reasonable safety precaution. Better yet would be a 3V system.