Garage pit

Am making plans on building a garage pit . I would prefer a lift but I want to use it for my motor home so I Don't want to spend 15,000.00 to 20,000 .00 . I did some looking around on the net and saw plenty of post advising others not to build a pit because of vapors and fires and all sorts of dangers . I have been around garages all my life since around the age of 13 or so and I have never heard of these dangers and have never heard of any accidents. I used a local garages that was out doors under a shed dozens of times. My plans are to cut my slab , dig down to the correct depth , pour pit floor with 4" of concrete' 12' around perimeter where walls will sit ( footer for wall) then build forms to pour walls approx 12" thick , might do 8" but with weight of motor home probably go with 12" will have rebar both vertical and horizontal ( vertical will actually be installed at time when I pour floor to tie in the wall to floor) oh, there will be extra thick vapor barrier in pit before pouring starts . Will also water proof ( use good sealer but not much is 100% water proof) , add a sump pump in case it does get water in it and a ventilation fan. JUST thought of something, will probably key in the walls to floor to prevent sliding of walls.

 

Sounds like you've about got it covered. Though the sump pit w/pump is a fair amount of work. You can't just suck crap out with a wet/dry shop vac? Or do you have a reasonable expectation of a catastrophic event?

 

I think the sump is for water that may penetrate the concrete

 

Well the sump pump is exactly what TX said above. I have installed several sump pumps and am thinking about a smaller than usual set up . I have a small pump now that is 110 volt and you can hook garden hoses to but it is not operated by a float as most are so I would have to monitor it in the event of flooding or whatever . hopefully I wont even have a need for any pump but in my experience with a basement that has no ground level areas like those with walk in or drive in access ( where a portion of your yard or land is lower elevation than the basement floor) there seems to be a greater chance of water penetration and this pit would be a tiny version of a basement without a walk in area. One other option is a sewage pump that does operate off of floats. they are generally smaller and can be bought for as little as $180.00.

 

Sounds like a plan!

On the sump pump topic. I have a raised floor home (1949) in Central Florida. I will get water under the crawl space on one side now. When I first moved in it was real, real bad, like 8" of water under most of the house. Anyway, fixed most of it with a swale in the yard, but I have a small harbor freight auto on pump for crazy heavy rain. Works great!

What part of the Country you in?

 

Word of the day for me...swale!
thanks for the vocabulary lesson!
B

p.s. it's NOT a small whale...

 

Sounds like you have it all figured out. If it wasn't for your motor home I would definitely recommend a two post lift. I paid around $3,500 for my two post Atlas lift (10k), and its one of the best investments I've ever made!

 

I want one!

 

You may want to check with your local county permits board before you get too far along. In my area the concrete supplier cant send a truck without an engineer sign off on the concrete mix.

Are you adding a pit to an existing garage structure that can already accommodate the height of a motor home, or is this a new construction build?

 

I live in Leesville SC , 35 or so miles west of Columbia. Curious ab out your crawl space. Generally there is a french drain on the outside right art the top of the footings of your house , this should take care of water entering crawl space. I have seen some crawl spaces that were dug deeper that yard and no point on yard was lower than floor of crawl space. You should not be getting any water in your crawl space.

 

Yes Remington,Existing shop , where I park my motor home. 14 ft tall at doors and taller inside. Motorhome is 12'6" tall. On the county code thing cement company don't care , will deliver no matter what.

 

Not sure what your profession is and if the shop you refer to commercial or private (hobby) but you may want to also check with your insurance company to see if they will write you a policy if you add the pit.

 

And if you add plugs or lights down there, it's a class 1 division 1 location so it will have to be explosion proof.

 

Thinking about this , will do some research in ventilation. Saw a video where a guy was in a pretty bad fire . Have been around garages a long time and gotta admit I was unaware of pits being a danger other than someone falling in. Used a pit a lot back in highschool never had a problem. Probably one reason I havent heard a lot about this is the fact that most shops have lifts and have for a bbn long time.My other alternative would be a lift as mentioned but that would not do much for maintenance I do on motorhome but that is done on less occasions .

 

Two long piles of crush and run will do the job.

 

IF I do this, I will incorporate a fan, saw several with cfm rating of anywhere from 600 to 1500 which would clear this out in a less that a minute. these are used in wood shops and the motor is isolated from the blower . When I pour or build walls of pit I will plump a 4" pipe at the bottom and run thru side then up and out under current slab. this pit will be 4 ft from the edge of shop slab and right outside it drops off a couple ft so I can dig a bit and have it exiting the building , also I can run a sump pump line along with it. BTW shop is a total area of 45x46 with the higher ceiling area where pit will be being 45x24 , Suppose I am in shop some 20 ft away from the pit and I pour gas from a can into a car, or mower or what ever , will these fumes make their way into this pit or is the danger when I am in pit and I drain oil into a bucket, are the dangers spoken of on several sites I have looked at somewhat exaggerated. I understand if I open a can of lacquer thinner in the pit, then I probably will be in danger but can normal shop use such as cleaning a car, installing various parts and so forth really cause any danger if I have a pit?

 

Gasoline vapor is heavier than air so it will go to the lowest point. That's why it's a class1 div1 location.

 

Wow - sounds like way too much work. Just go with a two post, you will thank me later!

 

the point is to use it with his Class A motorhome. a 2 post lift will not do that...

 

801 , have considered but have a class A 39 ft motor home I do maintenance on and am fixing to replace the air ride bags and all sorts of underneath stuff . A lift for the motor home cost in the neighborhood of 20 grand. I have a backhoe attachment on my tractor, actually dug my own in ground pool with it so digging is not a prob , plus I have poured literally tons of concrete , footers , slabs , have fully wired and plumbed several houses so I will do every bit of this at a fraction of what the lift I need would cost. My estimate is under $2000.00 , probably closer to $1500.00 and will be usable for every vehicle I have. Still might consider a lift and do something different for the motor home

 

Changed mind on pit , getting 2 post lift . pretty sure my concrete is 5 " thick . Most sites say 4 " minimum but 6" preferred. Saw one at a friends ( Oswalt Mustangs ) he said he thought he had about five " but noticed his had about an extra 12" heavy angle iron running perpendicular with floor on each base , looked real sturdy . Could do this even if concrete is 5 or more inches , would make it extra safe.

 

If I had to do it over again I would buy this lift due to the 3 stage front arms:
https://www.gregsmithequipment.com/Atlas-Apex-10-Plus

I went with the Atlas PV-10. It's been a great lift, but the 2 stage front arms make it a pain to rack smaller vehicles - sedans, coupes, etc.

 

That looks like a good lift , I have a concern with the total width being 137" . My shop is aprox 24 - by 45 and motorhome sits on one side ( most of the time and if I get the MH over within perhaps a foot of the shop side wall I have in the neighborhood of 14'6" left on the side where I would put the lift . If I want something like 2 ft between one of the lift columns and the MH, I would have to set the other lift column about a 1 ft from the other wall. Did see some single column lifts that would work and they are portable and for my own peace of mind I could put some anchor bolts in the side of the lifts base legs and sorta strap them down with a 1/2 inch steel plate .they are built to just sit on a flat surface but a little extra securement wouldn't hurt and would not interfere with its operation if done they way I am thinking.

 

Just ordered a single column lift , has 6000 lb capacity. will lift anything I have except my Motor home.