Brick Footing

[Elong123]

Hi,
I have a renovation project for an old townhouse. The demising wall is 22" wide brick bearing wall and it is about 18'-0" high, the two floor joists are embedded in the brick wall. The test pit shows the demising wall has a brick footing below.
I am not sure if the brick footing is allowed per today's code. I think I will have to provide a concrete footing under the demising wall.
Does anyone know any code's chapter that is related to a brick footing? Any recommendations on the brick footing reinforcing are appreciated.
Thanks in advance.

 

[hokie66]

Brick footings were common in the past. If there has not been settlement, there is probably no need to augment the footing unless the loading requires. Do you have a geotechnical report?

 

[EcoGen]

1) The length of the wall is 22 inches or you're saying the wall is 22 inches thick? That would be way too thick of a multi whythe wall unless it's hollow with cavities between each wythe.

2) The brick wall bears on a brick footing? So basically the same wall just continues straight downwards below the soil. Do you have photos to share?

3) How exactly is the renovation affecting the structural system? Are you increasing loads, replacing floor members, cutting openings in walls or floors?

4) For new construction you are not allowed to use brick bearing walls anymore but for existing buildings we use conservative estimates to determine if it has sufficient capacity for the anticipated walls. You don't need to replace it with a concrete wall or footing if it has sufficient capacity.

EcoGen Consultants LLC
Structural Engineers
ecogenconsultants.com

 

[le99]

A fix on the existing building support system should be based on the necessity, which in turn is based on the apparent structural defects and subsequent calculations or the proposed structural modification that changes the load that is carried by the subject support. I don't recall any code provision that prohibits the use of brick as foundation material, as long as it has adequate strength to distribute the load without causing excessive settlement or being damaged by potential differential settlement.

 

[Elong123]

Thanks for the replies. I don't have the geo-tech report. I attached a demising wall section and a photo from test pit.
The owner wants to add a third floor above current 2-story house and per the gravity calculation, the current brick footing is not sufficient to support the gravity load.
My main concern is the how the unreinforced brick wall to resist the lateral load (in my area, the wind load controls), the brick is good for compression but not good for tension. I think there has to be some reinforcing to take the shear loads.

 

[Elong123]

Here is the test pit photo

 

[le99]

Obviously, it requires foundation strengthening, you may consider underpinning. Also, this is a major renovation, you should find out what building code is expected by the local authority.

By the way, on the drawing, I don't think the red "property line" is the correct call-out, it should be labeled "centerline-(cL)" if necessary.

 

[hokie66]

Interesting. The section doesn't show an adjacent structure, but is that a party wall?