Residential Underpinning Advice
Residential Underpinning Advice
(OP)
I have a crawl space that I am currently planning to underpin. Three walls have 3ft Foundation walls (12" thick) with 2' footing. and one wall has a full 8ft foundation. Dimensions 13' x 22' x 13'
I have area carved up into 4ft sections plan to underpin the full thickness of the footing 2' but each concrete pier. Leave 2" gap between underpinning + existing footing and dry pack after 24hr cure.
Each pier will be 5ft High x 4ft Wide x 2ft Deep and here are my concerns.....
1. Worried about the peir shifting with the lateral pressure form the soil because I hoping not to pour the floor slab for a few months until I decide what I will do with the space and if I will want radiant floor, plumbing etc... I am a bit scared leaving it without a slab...
2. My soil type is a sandy mix... and Im worried about he sheer weight of all the concrete from 2ft Deep (full footing) and 5ft height. My concern is that due to the weight and load that the soil will settle...
Should I be worried?
I have area carved up into 4ft sections plan to underpin the full thickness of the footing 2' but each concrete pier. Leave 2" gap between underpinning + existing footing and dry pack after 24hr cure.
Each pier will be 5ft High x 4ft Wide x 2ft Deep and here are my concerns.....
1. Worried about the peir shifting with the lateral pressure form the soil because I hoping not to pour the floor slab for a few months until I decide what I will do with the space and if I will want radiant floor, plumbing etc... I am a bit scared leaving it without a slab...
2. My soil type is a sandy mix... and Im worried about he sheer weight of all the concrete from 2ft Deep (full footing) and 5ft height. My concern is that due to the weight and load that the soil will settle...
Should I be worried?





RE: Residential Underpinning Advice
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Residential Underpinning Advice
www.PeirceEngineering.com
RE: Residential Underpinning Advice
FYI: I have a background in construction and engineering I design and build downdraft HVAC systems for clean rooms of various types... I know my way around a job site and familiar with building science. I Was hoping to tackle this myself and manage my concrete contractor.
Would you be comfortable if I doweled rebar vertically every 12" to the with it embedded 8" w/ Sika Epoxy. and also tie piers together horizontally with rebar...
As for footing depth would it be acceptable if i went 1' deeper than the slab height?
Sorry if i am pushing the issue but just trying to make an informed decision with limited resources...
Thank you..
RE: Residential Underpinning Advice
www.PeirceEngineering.com
RE: Residential Underpinning Advice
Thank you very much
RE: Residential Underpinning Advice
I would be happy to pay for some qualitative advise on how to proceed and understand that it would be best effort given the constraints of the data I can get to you.
Please let me know if you can help....