ConnCode Publications

Class of Material	Loadbearing Pressure (pounds per square foot)
1. Massive crystalline bedrock including granite, diorite, gneiss, trap rock, hard limestone, and dolomite	200,000
2. Foliated rock including bedded limestone, schist and slate in sound condition	80,000
3. Sedimentary rock including hard shales, sandstones and thoroughly-cemented conglomerates	50,000
4. Soft or broken bedrock (excluding shale) and soft limestone	20,000
5. Compacted, partially-cemented gravels, sand and hardpan overlying rock	20,000
6. Gravel and sand-gravel mixtures	12,000
7. Loose gravel, hard dry clay, compact coarse sand, and soft shales	8,000
8. Loose, coarse sand and sand-gravel mixtures and compact fine sand (confined)	6,000
9. Loose medium sand (confined), stiff clay	4,000
10. Soft broken shale, soft clay	3,000

(Amd) 1806.1 Frost protection: Except where erected upon solid rock or otherwise protected from frost, foundation walls, piers and other permanent supports of all buildings and structures larger than 100 square feet in area or 10 feet in height shall extend to the frost line of the locality, and spread footings of adequate size shall be provided where necessary to distribute properly the load within the allowable loadbearing value of the soil. Alternatively, such structures shall be supported on piles where solid earth or rock is not available. Footings shall not bear on frozen soils unless such frozen condition is of a permanent nature.

Exception: Use Group U structures of wood frame or steel construction, 200 square feet or less in area and 12 feet or less in height are permitted to be installed above grade on a base of naturally durable wood, preservative treated wood, concrete or masonry. Such structures are not required to be designed to resist or protect against frost action.

(Add) 1806.1.1 Frost protection minimum depth: Except as provided herein or as approved by submission of adequate structural design analysis, the minimum required depth of the bottom of footings shall be 42 inches below grade.