Difficulties of Building on a Grade

[offthegridcortland]

I will be traveling to Virginia in a week with the intention of purchasing some land for my cabin site.  The land I'll most likely be looking at is largely on the side of a mountain.  I am thinking that my most inexpensive option in building in such a location would be telephone pilings or concrete piers.  I can see their be quite a lot of up and down.  A good bit of work to get materials in place.  I wonder if forum members would care to comment on difficulties or successes they've experienced building on a grade without doing lots of dirt work to level the ground- letting the pilings create the house's level?  I'd also be curious about maximum grades overcome by builders.  Thanks-  Aaron

[alex trent]

I built mine on a slope.  In 35 feet of house and deck it dropped 5 feet.  Looked like a lot less when I scoped it out.  I used concrete piers 4 feet deep and topped with 6x6 posts on which the beams were placed.

The build is on here on owner builder projects...Mtn Cabin in Nicaragua.  Came out great. if you go towards the beginning of my posts you will see a lot of warnings about a pier build. Need to be heeded, but do not let it scare you from doing it. Requires some extra though as it is not all spelled out for you in the code as foundations are. Speaking of code, need to check you local one as may be some restrictions on piers and posts.

There are some real advantages...preserving the land where you build id a big one for me.  If i would have dug....changes the whole site.

Here is my short list of important things on the piers and posts.

1. Need to have enough piers to support the weight and to run braces.
2. Pier footings need to be sized to support the weight. My concrete piers are 12x12 but at the base they are 18x18..so have a good foot.  I had not soil test or data so i figured worst case scenario in solid capacity.
3. Need to brace really well. Do not rely on the pier post connector for lateral movement..they are mostly for uplift and keeping the posts on the piers.  Braces can fix this.
4. You can run the concrete piers all the way up which gets rid of the connection, or run wood all the way up which does the same thing. You will notice in my build the back row of piers has not post/connection...my safety stop.
5. Unless you put the piers way down, you really cannot rely on them to prevent swaying and tipping over..again bracing is the key so the frame of the posts supports itself against there forces. Don't be confused by beach houses...those pilings go down 20 feet or more.

Don't be scared off...it can be done and done well and is every day.

[UK4X4]

You should not only consider the grade - but the soil too

my plot has sandy- cobbley clay

its relatively flat - compared to the mountainside its self................but with spring runoff from the plateau above the silts and sands move causing movement in the foundations

80% of the properties in my area have moved- some during building- some during the first year and there are only 12 houses.

I have to dig out 4' below my planned foundation location 4' to every side too and backfill with crushed rock, the rock alone is 8KUSD

Seemingly we are short of rock in colorado !

The cost of the foundation its self is aprox 23Kusd- 4 tons of rebar and 57yards of cement.

This puts me about 6-8X the average cabin foundation cost- before I've even put in a single nail.

So spend your time and choose carefully !

I bought outside my area of knowledge, and am paying for it now

Hopefully start the bloody expencive hole in two weeks.

Others here have paid for clearance - dig out and foundation less than I paid for just removing the tree's and levelling- where the site is makes a huge diference !

[Don_P]

I'm in the county with the highest mountain in VA, have yet to build on pilings. Doing the dirt work is the best way to get to a compliant foundation. A lot depends on the building official. You can do what you desire but that is into the realm of a structural engineer. The b.o. may enforce it or may not, I've seen it go both ways. Since code is about minimums it should give some weight to the argument for an engineer. I drew one a few years ago that had an anchoring masonry retaining wall that supported one end of the house, the rest was on tall piers. It gave us an open sheltered patio underneath and lateral bracing.  It got as far as preliminary conversation with the engineer and he thought it would be do-able.

[alex trent]

High is not the same as slope. If you have a flat high spot fine..if not need to turn a lot of dirt for a foundation.

Plus, there is the thing that is neglected...what people what in their house as far as aesthetics, etc.

How much does it cost to consult with an engineer with local experience to get an initial reading?  Not great plans, but a whoa, you cannot reasonable do that, or yep, if you do this and that you can?

[Don_P]

I don't know, for me, blueberries  . For anyone else, the initial consult is generally free.
From me to you all, I'm showing you the easy way.  I try to site the building on a good spot. You can save money down the road by buying a lot with a good site on it. Yes the engineer can help you build on a tough site, that might not be the easiest route to shelter.

Alex, my driveway hits 28 degrees, I live on the easy end of the county. The one at work is steep and long, I slid backwards down it fully loaded in winter looking at the drop to the pond below getting seat creasingly closer in the rear view. Your 5' site drop is well within what I would build a codebook foundation on. I would have crawlspaced it or made a walkout here, earth berming works. You have what pleases you and that is fine.

Aesthetics do have to somehow incorporate strength. If you are stuck on one aesthetic be prepared to pay its' costs, engineering is part of the cost when you step outside of prescriptive.

[MountainDon]

Yes the engineer can help you build on a tough site, that might not be the easiest route to shelter.

Just check with UK4X4