77 Ill. Adm. Code 870.TABLE B
B Footing Areas Required for Soil's Load-Bearing Capacity - Design Roof Load 20 Pounds Per Square Foot
Section 870.TABLE BÂ Â Footing Areas Required for Soil's
Load-Bearing Capacity − Design Roof Load 20 Pounds Per Square Foot
Section Width (feet)
12
14
16
12
14
16
12
14
16
Support Spacing (feet)
6
6
6
8
8
8
10
10
10
Support Loading (pounds per pier)
3200
3700
4250
4250
4950
5650
5300
6150
7050
Soil's Load- Bearing Capacity (lbs/ft
2
)
Footing Area (square inches)
1000
461
533
612
612
713
814
763
886
1015
1500
307
355
408
408
475
542
509
590
677
2000
230
266
306
306
356
407
382
443
508
3000
154
178
204
204
238
271
254
295
338
4000
144
144
153
153
178
203
191
221
254