Post load near edge of basement wall footing
Post load near edge of basement wall footing
(OP)
See attached sketch w/ calculations.
Plans Checker is demanding that a spread footing 2' square be provided, I am saying it is not necessary.
Slab, wall footing, basement wall already constructed, he wants slab cut away and new 2' sq ftg doweled into the existing.
In the future, I would call out the 2' sq ftg because it is just a few nickels more, but trying to justify the wall footing alone is OK here.
Plans Checker is demanding that a spread footing 2' square be provided, I am saying it is not necessary.
Slab, wall footing, basement wall already constructed, he wants slab cut away and new 2' sq ftg doweled into the existing.
In the future, I would call out the 2' sq ftg because it is just a few nickels more, but trying to justify the wall footing alone is OK here.






RE: Post load near edge of basement wall footing
Unfortunately you will need to widen the footing. With the width of footing you have (1'-4'') your will require a bearing capacity of > 5000PSF to resist the eccentric load for the column.
RE: Post load near edge of basement wall footing
RE: Post load near edge of basement wall footing
RE: Post load near edge of basement wall footing
This is a semi-custom home builder, and they are fairly tight with expenses, I am hoping the glulam "beam" concept makes sense so I don't have to direct them to put in that 2' square ftg. I also could change the (3)- 2x 4 post to 6 x 4 post and bolt to wall as ztengguy suggests, but that may result in very many bolts if the full 6330 lbs is developed thru the bolts alone.
RE: Post load near edge of basement wall footing
Can you split the large point load into 2 smaller point loads by placing the glulam up off of the concrete and supporting it by a post on each end?
RE: Post load near edge of basement wall footing
RE: Post load near edge of basement wall footing
It would be best to underpin the existing strip footing in this circumstance.
Mike McCann
MMC Engineering
RE: Post load near edge of basement wall footing
2000 psf bearing seems to be what is being used, which is really not very good material. Any chance the geotech can give a better assessment at this point? My starting figure is usually 150 kPa, or about 3000 PSF.
RE: Post load near edge of basement wall footing
Right now, the wall is seeing 1780 plf (assuming the weight of the concrete wall is included in this figure too), leaving only 220 plf available, and this would have to be spanned out via the wall. At 16 foot max span, that is only 3520#, and you need 6300# or so. No way without a higher allowable bearing pressure or a new footing.
Note that if the wall weight is not included in the 1680# figure, then the footing is overstressed at about 2500#/ft, or 1890 psf.
Mike McCann
MMC Engineering
RE: Post load near edge of basement wall footing
RE: Post load near edge of basement wall footing
Mike McCann
MMC Engineering
RE: Post load near edge of basement wall footing
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MAP
RE: Post load near edge of basement wall footing
I know I am treading on thin ice with this, but dealing with residential structures and home building contractors, we tend to bend the rules a lot more than heavy commercial structures.