Building on sloped land

[lockness]

Im hoping to start planning a new shop behind my house. My one concern is the land behind my house sopes downhill. Not sure how to measure it but if I picture a horizontal line, Id say the slope is downward around 25 degrees.
If I build say a 30x30 shop Id imagine the back wall would need to be at least 10 foot high to level the shop. Anyone have experience on building on sloped land? Im really concerned about the cost involved in making the land usable. Almost to the point where I may consider moving . Id like something pretty simple like a pole barn but if I need to bild up a big foundation then it seems I might as well go with a stick build. Any thoughts/ideas on how I can tackle this?

 

[junkman104]

I had a 30x50 put up back in August and had the same problem. $4200.00 later I had a level site to build on. It aint nothing but a thing. I have 12ft along the side and back with a swell cut for drainage and plan to plant some juniper to protect the bank. We finaly got the C.O. and get to move in the new house this weekend

 

[mjribeiro]

I had a 5' lowside, 900 tons of fill later it's nice and flat. 600 tons of quarry process, spread and rolled with a 9 ton vibratory roller - 300 tons of fill around the perimeter. That was a 6 digit escavation job!

 

[Bolt11]

Depending of course on the soil quality and how compacted you want it to be, if it works out for the site layout it is often possible to take the dirt from the high side, put it in the low side, giving you a level site about half the hieght of the original hill. This way you don't have to buy and haul fill, so it would be relatively inexpensive to do. And for a 30x30 it can't be too much.

 

[jhchoppers]

We had our 25 x 40 built on a hill. We just notched out the hill.




Click here to see the entire build

 

[Crazy Legs]

i'm working on this same problem in my backyard, my slope isn't near as bad as 25 degrees but i may have to add 4' to my back to bring it all up to grade, so far i've brought in 26 tons of fly ash and i'm working on building a retaining wall out of railroad ties, and alot of broke pieces of concrete.

Keep me informed on your progress!!!

 

[twostory]

I built footers, then a 41 inch tall stem wall for most of my garage. My property drops about 4 feet over the entire 44 foot depth of my garage. I then demo'ed and dumped the driveway concrete in the newly formed pit. Then I had 9 dump truck of fill dirt, compacted in 4 to 6 inch lifts. Then I topped this off with one dump truck load of #57 gravel. The slab sets on top of the gravel base.

My wife & I did almost all of this work, but I paid a crew to pour the slab. I built wooden forms for the stem walls. Reused this wood when I framed the garage.

Once you go over a 4 foot high wall, you normally will need an engineer to design it. So stay under 4 foot if possible.

If you can dig into the hill, and create a level spot that will save you thousands of dollars and time. A bulldozer and experienced operator can do this work in an afternoon.

Goto my profile for a link to my garage build.

Goodluck

 

[lockness]

I cant really dig into the hill since my driveway will be coming downhill to the shop.

My situation is alot like jhchoppers. Could you share an estimate of what it cost to the foundation you had done? I know having a pumper truck isnt cheap.

 

[GTS225]

This might sound outlandish, but........... Might it be possible to pour a "terraced" slab to build the garage on? (Local codes may have a big say in this.) Seems that if it's permissible, one could pour the slab in such a way that the center, or one side of the building would give quite a bit of overhead, thus allowing room for a lift, or taller vehicles. It may be a bit of a hassle in the interior, but if it could keep the initial price quite low........

Roger

 

[Ironcrow]

I just made this post in a thread about block walls:

"I have a 12 inch thick block wall on my shop. It is 14 feet tall and is a retaining wall. The grade behind garage goes up another 9 feet. Yes, the back of my garage is, essentially underground. Did I mention my lot is steeply sloped? In my case, the 12 inch CMU (Concrete Masonary Unit - "block") wall was selected as an alternative to a formed and poured solid concrete wall. There are two 5/8 inch rebars in every cell, four per block. The entire wall is poured full with 3000 psi grout. This is more rebar than the architect and engineer came up with, but I got a good deal on the rebar and I like overkill."

I would say, bite the bullet. Have an architect look at what kind of retaining wall you need for a level floor. Realize it will cost you. Make a decision to go for it or find a different site. Don't compromise with a smaller building, uneven floor, or piling up fill dirt to the moon to get a level spot. You'll hate the compromise.

 

[Sundowner]

did you say TWENTY FIVE degrees?
that's like a 1 on 4 slope. that's huge.
we were in Hawaii a few days ago and the road down into Waipio Valley is 25 degrees. it's mf'n terrifying, and they don't even let you drive it unless you have 4wd with a low gear.

I would reccomend that you do a combined borrow/fill earth move.

build a modest landscape block retaining wall into the low side of the slope and "borrow" earth to fill it from the high side of the slope to fill in behind the wall. cover the excavated high side with some geo textile prodiuct to protect it from slide and erosion. savvy?

the down side of this is that you will have to use the middles of sides as the egress for vehicles. not a big deal for a square garage.

 

[trs900]

I had the same problem, reason I decided to build up instead of digging out to get it level was for drainage as I did not want to be constantly fixing wash out around building with all the water draining towards it..

 

[Herb]

We had our 25 x 40 built on a hill. We just notched out the hill.




Click here to see the entire build

Boy, what a big waste of space that was. I had a very similar situation so I put a full basement with a roll up door there instead of filling a nice spot like that with dirt.

 

[sharpshooter]

Boy, what a big waste of space that was. I had a very similar situation so I put a full basement with a roll up door there instead of filling a nice spot like that with dirt.

When I was looking at the pictures I thought man thats gonna be a nice spot for some extra storage then the next pic it was filled in, I was surprised, but hey Im sure he had his reasons on not using it.

 

[jhchoppers]

The cost for our build was 27K. This only was for the outside work, no electrical, insulation, or sheet rock ... We are doing all that ourselves.

I did call on some buddies to help, but I paid them $20/hour. Just make sure you get several estimates. We got one as high as 58K for the same thing !!!

I would call several concrete guys yourself, to get a ball park.

Also, in hindsight, I should had put preformed concrete form floors in, then I could of had a basement for about 7K more. Our first estimate for the basement was 20K, but I found a guy who would of done it 7K after the hole was filled with rock

Hope this helps

 

[KELLHAMMER]

I designed a 30 by 60 garage. Two levels on a steep lot. We used a concrete plank to create the second story garage floor. The attic is an apartment.

 

[KELLHAMMER]

This is a garage I designed for a friend. We've been building it for about 6 months. It was a barn for horses. We turned into a 5 car garage. The upper half of the original is going to be for the kids to hang out. The new addition has a 14'-0 ceiling so the will be no interference for the 2 post lift. Notice the sloping track for the 16'-0" wide garage door. It has a 2 zone infloor hydronic radiant heat system. Powered by 40,000 btu electric boiler.

 

[lockness]

The cost for our build was 27K. This only was for the outside work, no electrical, insulation, or sheet rock ... We are doing all that ourselves.

I did call on some buddies to help, but I paid them $20/hour. Just make sure you get several estimates. We got one as high as 58K for the same thing !!!

I would call several concrete guys yourself, to get a ball park.

Also, in hindsight, I should had put preformed concrete form floors in, then I could of had a basement for about 7K more. Our first estimate for the basement was 20K, but I found a guy who would of done it 7K after the hole was filled with rock

Hope this helps

Wow thats not bad at all for that much work. You have given me hope. Thanks for the ideas.

 

[kcclark]

I need to build a garage into a slight slope. Ground is around 2' higher at the back versus the front. Garage ceiling will be 12'. Topping off with gambrel roof for attic.

Was planning on using poured concrete for walls but $ situation has changed (gotta spend some on another project). Is a pole building out of the question because of the back/side walls being partially underground?

 

[arbee]

You can see the details of my situation here: http://rbgarage.googlepages.com/gradingandfoundation

I "only" had a 6 ft drop from one corner to the other though.

 

[JMURiz]

KELLHAMMER: Those are some awesome designs!

Lockness, you should contact this guy, those are some nice looking ideas.

 

[PAToyota]

Is a pole building out of the question because of the back/side walls being partially underground?

You would not want to backfill against a pole building. But you could pour or lay block walls up high enough that it is out of the ground on all sides and then frame on top of that.

 

[Bigger Hammer]

If I were in your shoes I'd seriously consider a 2 story type structure where you can have a workshop below and an elevated slab for parking above. Since you are already driving to the high side anyway you would basically build your garage with a walkout basement. While an elevated slab or precast slab panels might get into some big ching it wouldn't surprise me if it was comparable to an extensive earthwork scope. Not to mention, earth workers are notorious for sticking it to ya if they get into something that was unforeseen.

Here is a pic of a 1940's cabin rebuild I did about a year and a half ago.

Hillside const.

I dug the foundation into the hillside and backfilled the crawl with the spoils. But in your case you could do something similar and simply pour a slab instead. There would be a lot of dirt coming out of the hillside on a 30x30 building but it wouldn't be hard to burn it up around the perimeter after the foundation was in place. btw, the slope on that cabin was intimidating to look at but it was steep!! the foundation is only 12' from front to back and it dropped roughly 5'-7'.

 

[shocksystems]

I designed a 30 by 60 garage. Two levels on a steep lot. We used a concrete plank to create the second story garage floor. The attic is an apartment.

Kellhammer: That place is beautiful. What part of the country is that as well? Cheers! Jim

 

[kcclark]

You would not want to backfill against a pole building. But you could pour or lay block walls up high enough that it is out of the ground on all sides and then frame on top of that.

Been trying to avoid stick built this whole project but now I don't seem to have much choice.

 

[Yotaforce]

Same problem I had. I had a hillside that would've required a 6-8' retaining wall to get a foundation. After finding out how much it would cost, I had a contractor with a dozer come out and he just took dirt off the highside and pushed it to the lowside. In the end, I had a bank of dirt only three feet high and a level area about 40x70 to build my 30x40 garage. Plus, it only cost about $100 per hour for the dozer work and it took him about 4 hours(between equipment failures) to finish it off.

 

[kcclark]

Flattening things out isn't much of an option for me. Playing with the grade would run me into problems with the county because of drainage issues. Making the ground level would run me into problems with the township because they would make me shorten my proposed garage.

 

[Jamesnlee]

Hello, I'm new to this site and sorry if this has been discussed already but this thread is the only one I found that is closest to my situation. Wanting to build a 24x32 garage but it is on a severely sloped site. The site probably slopes to 3.5-4 feet starting at about 4feet in to the 32 planned length. See pic attached. 1st step of course is to demo the site, get stumps out etc. I want to build the land up to the level of the boat. So she can pull right in.

So, my question for you all would be what would be a manageable leveling process for me to do myself. I've gotten estimates and they range anywhere from 9-25k just for the land leveling/prep.

My plan is to build stem walls around the perimeter on footers, reinforce with rebar, fill cores, etc. Then back fill "hole" with compacted lifts etc.?

Would appreciate any suggestions. Thanks

 

[rburke65]

Welcome James Lee to The Garage Journal. You should start your own post for your build. Top of page, in the black banner...NEW POSTS. That being said, as to what would be ‘manageable leveling process’ ..... I don’t know what that means. Break out a shovel or break out your wallet. Site preparation is not inexpensive.

 

[theoldwizard1]

Would appreciate any suggestions. Thanks

The stem walls need to built on footing that go below the frost line. The stem walls need to be able to release drainage at multiple levels. Drainage tile exiting through the side walls at several levels is a good idea.

You can use reclaimed/crushed concrete for but it has to be small enough to be compacted every 4"-6". Bonus of crush concrete is that it does not retain moisture like dirt. The top 1' or so should be clean sharp gravel, like crush limestone.

 

[Jamesnlee]

Manageable, meaning a process that I can do myself with the use of contractors over charging etc. I'm pretty handy and have done just about everything with my houses etc. I would rent little mini excavator, can get free fill dirt etc. Thanks for the New thread idea. I've done that.

 

[DarrenF]

Hello, I'm new to this site and sorry if this has been discussed already but this thread is the only one I found that is closest to my situation. Wanting to build a 24x32 garage but it is on a severely sloped site. The site probably slopes to 3.5-4 feet starting at about 4feet in to the 32 planned length. See pic attached. 1st step of course is to demo the site, get stumps out etc. I want to build the land up to the level of the boat. So she can pull right in.

So, my question for you all would be what would be a manageable leveling process for me to do myself. I've gotten estimates and they range anywhere from 9-25k just for the land leveling/prep.

My plan is to build stem walls around the perimeter on footers, reinforce with rebar, fill cores, etc. Then back fill "hole" with compacted lifts etc.?

Would appreciate any suggestions. Thanks

buy your own machine (bobcat) and sell it after? I did just that, but haven't sold them yet. Put an add on craigslist looking for clean fill, and fill the area in small lifts after stripping off the vegetation and topsoil. All it would take is a guy who is digging out a basement to fill your whole area. We had good luck with this. Just inspect every load. Bring up the last foot or so of the building area with gravel.

 

[kbs2244]

I said this before, but whenever I see l a slope I see a chance for a garage basement.
Find a concrete guy who has done "hillside" home foundations.

 

[xyster101]

I had about 8 ft over the 50ft garage. Just dug it in. Bonus, that attic level was only 4 ft above finished grade, so a ramp and I store my ATV, mower, wood, all kinds of stuff. 1200 sq/ft of storage space!

 

[Jamesnlee]

That looks awesome. But I think my site is opposite yours. I need my garage door at the top of the slop. Driveway can’t swing around or I would just dig into hill.


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[CraigStu]

As you think about different ideas be sure to check w/ the county. We added a 3rd bay to our garage on land that sloped both to the side and rear. Typical poured foundation and block wall to about 2 ft above the finished floor slab. County said that if the floor were more than 2 ft above the land we would need piers to support the slab which would have been quite the extra $. The solution was to drop the floor 3 steps below the existing garage floor.

 

[mercury304]

Just dig into the hill , and hope you don't hit large rocks.

 

[Sportsman762]

I helped a friend build an addition on their garage. We rented a large backhoe and did the work ourselves. The cost was pretty reasonable, and gave us an excuse to play around.