smittenbritt

We live in California, so prone to earthquakes. We have a small single story home that was built in 1939. It doesn't have a basement but it has crawl space. I know in the future we will need to think about foundation repair. Also we would like to think about extending the living space in the future. So my stupid questions are...

I know the current foundation Won't have been built to accommodate a second story so if you upgrade the foundation as well as a repair would that take a long time to get done? Can you continue living in that house while work is being done? I've seen pictures of houses on stilts that doesn't look like something you'd continue living through?

Also if we were to add on (outwards not upwards) but do it before we upgraded or did anything to the foundation of the main house would that make it difficult or impossible to do the foundation on the original part of the house?

Please excuse my ignorance, this is our first house..never had to do these things before.

nealtw

These are all great questions. I think your best bet would be to have an engineer design your foundation repairs and sizemic upgrades. If that is extensive it may be easier to replace it if you would like to raise the house anyway. The city will tell whether you can live in the house will it lifted. Your first step is an engineer.

CallMeVilla

Yes, an engineer and an architect so you can better estimate the project scope, time and cost. Have to be careful in CA because they will try to force you into changes that may be cost prohibitive.

The old foundation will probably have to be underpinned or worse . . . Explore the structural problems first. Then decide if it is worth the investment.

Cheers from sunny San Diego . . .

smittenbritt

Thanks, we were told on our property inspection that eventually we would need to at some point in the future do some repairs...sounded Luke metal band aids. They said it wasn't an immediate problem though. We would like to also add on some more space as it's not a big property. And the lot is zoned for a duplex. Although I would rather up that out so we still have garden for our daughter. I know this would be really expensive so it would be a few years off I think I just wanted to get my head around things before we do one thing first and wish we had done the other. Also because my husband intends to consult with an acquaintance about it all and I'd like to get a better understanding about things before we "ask" so we ask the right things.

nealtw

An engineering company that can do structual and geotec (dirt) is the guy to talk to first, before you get all your dreams in place. Before they come out you would want to dig down expose the footing at the bottom of the foundation as they would want to see how big the footing is and they may want to measure the dirt it is sitting on. They would be able to tell you what needs to be done to it. You are not adding a lot of weight by adding a basement.

CallMeVilla

Basements are rare and problematic in California. Most houses are on slabs or have crawl spaces and use piers. Local engineering companies will know the legal limitations per building code and so will architects.

I have been under homes which had 1/2 basements where they captured the "found space", added walls and flooring. Very rare . . .

BridgeMan

That all depends on one's definition of "not adding a lot of weight."

The approximate weight of just concrete walls, floor and footings for an average-size (1600 S.F.) basement will be approximately 274,000 pounds (137 tons). And that's not counting any interior support structure (girders, columns, pier footings, etc.).

smittenbritt

Thanks we don't intend to add a basement...just a few rooms such as extra bedroom, family room, garage and small wet room.

nealtw

Bridgeman: If an engineer said the foundation and footings were enough to support the extra weight the added weight on the foundation would be wood struckture and finnish inside and out for the exterior walls and taller posts to pick up the exsisting pointloads. The concrete floor and interior walls don't add weight to the foundation.
My piont was in comparison to building up instead of under.
Smittin: I would still call an engineer to look over the foundation and design any repairs that are needed and do the earthquake upgrades.

smittenbritt

Thanks. We will look into doing that.