Garage in a hill

[Jonessa4]

I am going to be building a new garage. The only unfortunate thing about the 3.5 acres I own is... it’s all on the side of a hill. So, I will need to dig down and use blocks to level out the base of the garage. Is there a way that instead of doing 4 walls of 6’-10’ block, that i could get away with 1?

 

[Red 17]

How much of a slope are you working on? And which way will it point--downhill or to the side? What is your surface water runoff situation?

 

[ford33]

Need your location to provide correct answers. Pictures or a sketch would be very helpful.

Are you asking about building into a hillside with only one wall of block? If building into a hillside I would think you would need 2 sides or 3 sides plus proper drainage to hold back the many tons of soil and water that is bearing down on your structure.

 

[SGKent]

My 2 cents is that to do it right you need a soil engineer to answer that. Soil type, moisture content, geology etc., are all going to play a part. Holding back 1' of hillside is different than 15' of hillside, and even 1' of hillside can be hard to stop if the movement uphill from it is pushing it. If it is clay that gets wet at times the problem is different than a rocky cut. The question you are really asking is how big a retaining wall do I need to hold back this hillside. A retaining wall that comes to lean a little after 10 years or lifts a little from roots isn't nearly as dangerous as a wall holding a structure up that does the same. Also I doubt if permits are going to be approved without an engineering stamp signing off.

And sometimes they are wrong too: Oops

 

[JamesW84]

Is this the kind of hill you're talking about? The far end is about 5 ft cut out. I made it wider than the shop so I can slope away from the foundation. No fill necessary, so no soil engineering, engineered fill, compacting, proctor tests, etc

 

[rsanter]

Not enough information.

Basically you can dig into the hill to make a flat area to build plus added area to have open space around the shop.
Or you are going to build one or more walls of the shop that are also retaining walls

Bob

 

[Jonessa4]

The garage would be facing down hill, on a 25 to 35 degree slope

 

[CombatNinja]

You sure about that slope? Anything between 25 and 35 degrees is wicked steep but that is still a huge range. 25 might be worth looking at. 35 degrees is pretty much the side of a mountain.

 

[CombatNinja]

See that Land Rover there? It is facing up a manufactured 35 degree slope for your reference.

 

[JamesW84]

We need to see pictures.

Are you sure that's the slope? To have 125 ft of flat ground, you'd have to dig down nearly 60 ft in the back.

What size shop are you wanting? You might be better off going wider rather than deeper. My house is an earth berm with 8" thick poured concrete walls 6ft in the ground.

 

[tez929rr]

Yeah, a 35 degree slope is an 88 percent grade.

 

[Corsair4360]

Our new shop is built into a hillside. The site drops 7 feet diagonally across the building, hence the basement under the garage floor. The building is 50 feet wide and 35 feet deep.

 

[PWC Repair]

Check my thread out. I cut into the hill to avoid the soil and compaction issues that James mentioned.

 

[firebirdparts]

Don't knock it.

My garage is always warm in the winter and cool in the summer. We park on the 2nd floor also but maybe you don't want to bother with that.

 

[ScottsGT]

My home is built like this. Not block, but 10" thick poured concrete. My garage is a side entrance, I have a 16X24 workshop on the down hill side. When I bought the house I rented a concrete saw and cut a window into the work shop area. It does stay much cooler.

 

[engineer2]

There is a GJ topic from the guy in Switzerland building his garage into the side of a hill.
Interesting reading and it looks expensive.
https://www.garagejournal.com/forum/showthread.php?t=348387

 

[1931S/X]

Could you cut back a larger footprint than the garage, do separate retaining wall and have space around the garage?

 

[isb cornbinder]

Our city lot is 50 feet wide, at the lane. The lane drops/rises about 8 feet over the width of the lot. I built my shop in 1990. It is built on a shelf, so to speak. The shop is 865 SF.
My wife and I are not likely to move any time soon, but we both agree this is the last hill we will ever live on.
I was moving my 1938 John Deere "D" into the shop. The brakes could not hold it back. I stayed on the tractor and guided it safely to the bottom of the lane. That wild ride was more than twice the top speed of the tractor. The engine got a real work-out. I sold the "D" the next week.
My neighbours almost never speak since I cut them all off on freebies. When we get snow, suddenly we are the best of neighbours. We have 4X4 vehicles. I am not an UBER service.

 

[mcbane]

This reminds me of the recent topic re: a garage that was built square to a sloped slab...

 

[b7labelle]

This reminds me of the recent topic re: a garage that was built square to a sloped slab...

Oof, I can only imagine..

 

[paredown]

I found it hard to search this topic on the forum, but my dream build would be built into a bank, somewhat like what Firebirdparts has shown, although I would be looking at garage at grade, and shop space above.

I found this build--there are two threads--it is a nice in-bank build. This build was mainly DIY using CMUs parged to hold the bank/act as retaining wall on the embedded end of the building:

https://www.garagejournal.com/forum/showthread.php?t=212873

https://www.garagejournal.com/forum/showthread.php?t=387059

 

[rerod]

Id say its doable, but concrete usually cracks so you should fore see water trying to make its way in and the humidity it brings along. Plus the fact concrete wicks water.

 

[ScottsGT]

Id say its doable, but concrete usually cracks so you should fore see water trying to make its way in and the humidity it brings along. Plus the fact concrete wicks water.

This was my concern when I purchased my house 25 years ago. No issues what so ever. I'm not sure what the builder did to seal it all off, but it is very dry in my basement. The fact that it is built on/in very sandy soil might be a factor as well. No clay to hold moisture.
Years ago I had a Sears Termite guy trying to sell me on drilling holes in my basement slab and pumping in poison. I asked if they were going to be responsible when my basement turned into an indoor swimming pool. He said he would discuss with his boss and get back with me. Never heard from the guy again.