Pole Barn vehical service trench construction?

[wroughtn_harv]

I think you should believe them Don.

The TI plant in Dallas lost a couple of welders about five years ago due to argon gas if I recall, in a pit.

So it isn't just explosive gases that can ruin your day in a pit-trench-manhole-tank. Anything that displaces breathable air is a hazard. I would say oxygen, but a tank full of H20 will ruin a day without proper breathing apparatus.

Probably thirty percent of my work time in the telephone business was in manholes or splice pits. Even in the old days a quick way to lose your job was to be caught in a manhole without proper ventilation. Of course in the old old days that meant a sail. Yup a sail.

A sail was a canvas tarp hung over the manhole guard in such a manner as to direct wind currents into the manhole. If there was no wind or if your sail was on the wrong quandrant for directing the wind properly it was a write up. Write ups were bad. Sorta like an official dressing down for the record book you might say. /forums/images/graemlins/confused.gif

 

[SPIKER]

thanks for the info so far guys:

I will not normall have any think in side the barn that has fume capabilities. cars will come in get worked on and go out. I will have fans in there anyways. as they are needed for heat circulation or cooling circulation. I had though about using a bath room vent type fan with a pipe to suck out air from bottom of it.

propane and gasoline fumes oil is heavy and will sink, but nat gas will disperse and is lighter than air. I don't yet have any aclyne to worry about but will eventually. I was thinking about the sepperate pours myself. that way it would be easier to do. several days appart leaves time to refine it and plan for the next pour. the barn flooring will have concrete slab with in-floor radiant heating tubes (PEX-AL-PEX.) 5/8" on 12" ctrs. Not sure if I should worry about heating the pit or not.? any thoughts??

ok so if i reinforce the walls they shouldn't bend/cave in but how should I KEY the top of the walls for the floor? Should the walls go up to the height of the floor or would it be better to pour the floor right over the top of the walls ? (the way I think it would be best.) I could then leave re-bar out of the top of the pit walls to catch the floor. in that way the hole floor would have to move to let the walls top cave in or bend.

Ok keep the ideas comming I'm likeing them all so far. I want to keep the floors all level but I could easly build small ramp out of steel on each side to raise the car height ! I could build that very easy and make it adjustable too! lol.

I still want some type of PIT theough because of the storm problem the last two years we have had tornados with in 1/2 mile of the place and incured wind damages severl additional times. this place is on top of one of the highest points in the county. which gets it some protection form the tornados, (they move off to the side one way or the other when comming in) but it also means that there is no way to stop the really high winds from damaging stuff. I'd rather at least have some type of HOLE to get into incase one does eventually get over the top! /forums/images/graemlins/blush.gif

Mark M

 

[bebster]

Mark, depending on how big your pit is and how much time you plan to spend there, you could skip the radiant heat into it. The floor around it will be warm and it's like being in a pit in the middle of a warm radiator -- not too bad.

As to connecting the walls to the slab, I've attached a drawing of how I'm doing it. Not a pit, but where my barn slab meets a frost wall under a garage door. The connection principle is probably the same using a bent 1/2" rebar "dowel". The rebar goes into the wall and sticks up. When the wall is set, it can be bent to the horizontal position and wired to the rebar or 6" wire mesh in the slab. This plus the 2x4 made keyway helps join them together. Don't forget to insulate well under the slab, the pit and around the wall. Hope this helps.

 

[MarkV]

Mark,

I really don't have much to offer on the construction of a service pit. Sure can see how it would be handy though. 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

 

[EastTexFrank]

I'm a little behind you, I'm still planning my pole barn for this spring/summer. I too thought it would be nice to have a service trench in it since I'm in no shape these days to scoot under cars ... trucks I can still manage. I went off the idea after talking to some of the mechanics in our little town. Almost to a man they were against service pits. Apart from all the other safety issues already mentioned the clincher for me was that they said it was almost impossible to keep them clean. No matter what you did there was always oil being spilled on the floor and it was such a pain to clean up, either that or risk slipping and fire hazards.
If you want a tornado shelter, why not a commercial one ... dig a hole, drop it in and backfill. It would save your wife from having to climb down into a gunky service pit but if the tornado was real close she probably wouldn't mind too much. /forums/images/graemlins/grin.gif

 

[Phred]

Spiker,

I have a similar need but higher cellings. I am looking to go the lift route.
The other guys have made some key points about the pit and I agree with them. These things are a safety hazzard and will be a pain to use to swap out ball joints on a pickup or similar task. Want to pull a tranny out of the pit? It can be done but a lift would be so much easier.

Also if you move you can take the lift with you, or offer it as an add on to the price of your place for the new buyer. He will know that you can't take the pit with you, but the lift can be moved.

Bendpack has some lifts that you can put a heavy duty diesel pickup on for under 3K. Might be cheaper in the end unless you plan to never move.

Fred

 

[Egon]

Pits are really not that conducive to a good working location for the underside of a vehicle. Oil changes excepted.

They are also a very definite safety hazard both for falling, combustible gases and lack of oxygen. And yes, those stories are true.

For example: where is the advantage in changing a ball joint, doing the brakes changing tie rod ends etc. The pit walls interfer with much of the maintenance required. In fact I'd rather do an oil change without a pit.

Hoist is a different matter. It allows access to the vehicle and takes the wheels off the ground.

Just some thoughts.

Egon

 

[SPIKER]

Hi Guys:

I'm up on the things about not having one, but I don't have height for lift, (my pick up is already 7.5' high and that means only 3 foot to barn roof joist..) I can hardly bend now with my back problems so getting under them is hard. I have a new starter setting in my trunk now for the truck. and have not installed it cause I can't bend under there anymore. (next week I'm getting a MRI for my back surgery that I've needed for over 10 years) I can hardly lay on the floor or set up much. yeaterday I cut wood for 4 hrs, and wasn't able to sleep much form back ach.

I don't want to be stuck working on trucks cars ect in winter anymore but intill the barn floor is done i don't have much choice.

I will attempt to get the truck out to the work shop to repairs later today and use fork lift to get it up a few extra ".

anyhow. keep the ideas comming. as this spring after it warm up the floor will be started and I want to make sure I have a way to get some sort of thing in there for work and tornado safety.

(the 2nd reason I really want the pit for a hiding place after the last year of just missing the high wind leveling effects!)

I usually will have my oil changed at WALMART for 18 bucks rather than do it myself but for a transmision filter change no one around here does it anymore they just want to change the fluid not the filters. SO those I will be doing. For $18 its just not worth the effort to change the oil anymore!

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

 

[missourihick]

When you pour the floor remember to put in a step at the top of the pit wall so you can cut some 2x 12's for a floor to cover the pit so you don't fall in the thing at night. I personally like a pit. Of course I am the only one.

 

[AV8R62]

I built a pit about 15 years ago that served me well
it was only about 26" deep so I sit on a creeper and do service work under a car or park a snowmobile beside it and
stand in the pit. it was also open on the front to allow for ventilation my garage was built on a slight grade so it saved some on fill dirt as well .

see drawing