Foundations for modular homes

[nutbutter]

Hello,
I'm assisting in the design of a foundation and tie-downs for a single-wide modular home. I've never done one of these and I'm wondering if anyone has any advice or could steer me to a good reference. I don't really know where to start. I don't even have a loading, so I need to come up with a value for a single-wide modular home. I guess my bet is to try to contact some manufacturers. I'm imagining that the modular home will be up on blocks of some kind.
Peace,
NB

 

[jartgo]

I'm going to preface this with, I know very little to nothing about homebuilding, modular homes, or mobile homes, nor am I a geotechnical or structural engineer.

Having said that, if I were attempting to tackle your problem, I wouldn't contact some manufacturers, I'd contact THE manufacturer of the home in question to ascertain the actual dead load of the structure, hopefully they could give that to you in a useable form. Assuming that is the case, you could do a basic structural calc to determine what the ground pressure would be under the foundation and design your foundation to accomodate that pressure (of course accounting for additional loading from furniture, appliances, live loads, snow loads, etc.) in combination with the strength of your existing or modified grade, plus a factor of safety.

I didn't realize modular homes had tie-downs. Do they in fact have tie-downs like a mobile home?

I'll end with this: unless it were my house, I wouldn't mess with it. There's likely a contractor in your area that could have the job completed more than adequately in less than a day. Single family homes are not normally required to have an engineered design, and I wouldn't think the foundation on a home that needs tie downs would be critical.

The building department of your local government could probably help also.
Just my 2 cents.

 

[msquared48]

The manufacturers have tiedown diagrams for their products according to HUD requirements which are even more lax than the IRC. Check with your manufacturer.

Mike McCann
McCann Engineering

 

[49merc]

Check websites for HUD, there is a manual for foundation design for modular homes, single and double wide. It's pretty straightforward. I was asked by a lending institution to check a couple of foundations; I haven't found one yet even close to adequate.

 

[graybeach]

nutbutter,
Check out Tie Down Engineering (

http://www.tiedown.com).

They have some useful design information and were very helpful on the phone.