PEMB Lean-To Addition Foundation

[redbridge]

I am designing a foundation for a PEMB addition. The plan is to construct a stand alone metal building right next to an existing metal building. The building manufacture does not want to construct a lean-to because he doesn't have any information on the existing building. So their plan has a new column right next to an existing column. Is this normal? How would the foundation work with 2 metal columns that close? I do not have any information on the existing foundation. Attached is a drawing.

 

[SlideRuleEra]

1) Is this normal?
2) How would the foundation work with 2 metal columns that close?
3) I do not have any information on the existing foundation.

1) Looks like a good solution to me.

2) Use plenty of very good material for the addition's subgrade and compact it thoroughly to minimize differential settlement between the the existing building and the addition. I would not connect either the new foundation or the new frame to the existing building. Other than weatherproofing, the two structures are completely independent.

3) Have a utility locator find and mark all existing underground services such as water, sewer, electrical, etc. If safe, dig or probe around the existing building to get an idea of the extent of the existing foundation. Design the new foundation with the goal of not disturbing any of the existing underground utilities.

http://www.SlideRuleEra.net

 

[redbridge]

Thanks for your input. I am worried that I won't be able to separate the foundations if the columns are that close together. Attached is a drawing of what I am assuming is the existing foundation with the proposed foundation. Can I add to the existing foundation like I have drawn up or should I have them move the column so there are two separate foundations.

 

[SlideRuleEra]

I would move the column - see my Item 2 above for one reason.

Another reason - when there is an alternative (moving the new columns), not a good idea to work on (drill for dowels in this case) an existing loaded foundation... if existing foundation unexpectedly "moves" or "breaks"... what do you do then? Just dig and place the new foundation, leave the existing foundation alone.

http://www.SlideRuleEra.net

 

[oldestguy]

I think you may end up with a problem at the roof junction. Somehow that existing roof has to be integral with the new or leakage down into the building will be an on-going nuisance. I think, doing a study of what you have is a must and then workout plans to actually attach the new to the old. That roof must be integral somehow. Much of what is needed depends on the weather.

 

[dcornelius]

How are you handling the rain/snow runoff? This may be a separate nightmare.