Foundation Advice

Hello Everyone!

It looks like I will be buying my first two buildings from different sources. First, my living space will be a tiny house on wheels. I am buying the shell and finishing the inside myself. Second will be an Old Hickory Shed building for the Cookhouse. The same, buying an unfinished shell. Eventually I will buy two more of the Old Hickory but this is where I will start.

My question is regarding the footing or foundation for each type. Once the buildings are on the property they will never be moved again. For the TH on wheels should I sink some kind of deck block and attach a 4x4 that will hold the building up off the tires? Should I remove the rims and tires entirely? Should I leave the rims on but take the tires off? And still raise the building enough to take it off the rims?

How about the shed buildings. They will come with runners but I must provide some kind of foundation. Cement pad or block type, my choice. Is one better than the other? There will be some plumbing that will run underneath so I must raise it at least 25" above the ground. Much more than that and I run into issues with County Codes. To keep critters from making their home under my home I will use a lattice with 1/4" hardware cloth behind it. Not only snakes but I have to deal with those giant crickets they call Mormon Crickets. Seriously those things are the size of newborn kittens. Yes they can climb but even though they have tiny wings they can't fly, maybe I'll build a moat of fire... LoL

If you have any experience with these foundations I would love to hear your advice.

Thanks so much,
Sherry

For what you are wanting to do we use concrete blocks. These blocks might also be called cinder blocks.

First, we level the area we want to place the building. Or determine how many blocks it will take to get the building level.  The blocks are placed at the corners of the buildings.

I can't advise you about county codes as we have never lived where we deal with those.

Hi Sherry;
As you are in California you will not need to worry about a deep frost

A poured slab is best but seems overkill for a storage shed.

I would use concrete pier blocks at the corners and on any long runs.
They are easily available premade up to 3' tall. They do require a tractor to move at that size.
Or you can pour your own using cardboard "sonitube" forms. (Much easier if you have no tractor)

Your tiny home should be raised off the tires and removed they should be stored out of the sun and weather.
Small concrete slabs can be hand dug and poured for "jack stands" or dunnage to sit on.

Sherry,

In most of California the required minimum footing depth is 12". Pouring a slab may be cheap - if you reinforce it, form it and just order concrete, or expensive if someone will do it for you. For me the greatest challenge is to find someone to bring small amount of concrete and not charge like for some high end material. Smaller amounts for grouting I mix myself, but would not recommend it for a slab.

This answer is more in the "if I had to do it again" department but may be relevant to the plans of the OP.

I have no interests/investments in the linked company, but have purchased their building jacks before and have found them good quality.  We had a rather large deck installed some years back and had a sunroom built upon the deck at the same time.  As we are in north central U.S plains area with high water table, deep freeze depth, and heavy clay soils, we went with the contractor's advice to set the deck on poured concrete posts sunk 5 feet into the ground.  Unfortunately for our location, this was probably inadequate.  Since then, the ground has shifted laterally and now the main support beams are at risk for misalignment on the concrete footings.....or possibly falling off of the footing altogether.  Additionally, the ground has heaved vertically so that the door and windows of the sunroom are mostly out of square.  Over the past few years, I have been able to alleviate *some* of the problem by local jacking of the beams under the deck and placing a few of the jacks noted in the link below at strategic locations in attempts to level the structure. Not easy, but it does work!  But if the OP is building in anything similar for soil type, it may be worth placing the tiny-home structures on such jacks as they are adjustable any time you wish to shift the level of the building.  Hope this may be of help....

https://ellismanufacturing.com/collections/screw-jacks

I would like to add to John's cautionary tale:

You haven't described the land, geology, geography, fire risks or extreme weather. I'm just going to assume from your identified region that you're in earthquake country!

I'm getting more and more concerned about the number of people I know who aren't preparing for the worst because it's more work and costs more money. Please think about the extremes we're seeing all across the planet, assess your risks, and consider what engineering could make the difference between your house being levelled by what Mother Nature might decide to throw at it!

Thanks so much everyone. In my case it sounds like the purchased blocks that hold up the posts best suits the area I will build on. Awesome sauce!!!

Can I ask a few questions about your general plans?
- Have you thought of rainfall collection instead of a well?
- Could you build the cabin from scratch?
- Will you be able to work part time when you retire?