| 1. | Coordinate with the geotechnical consultant and the civil consultant.
Keep surface drainage away from the building. |
| |
| 2. | In addition to waterproofing requirements, floor levels which are below finish grade shall have a
foundation drainage system where possible. Drainage pipes shall be smooth perforated drain pipe in
gravel drainage bed, protected with filter fabric. Filter fabrics and mats shall be specified and
shown. Provide gravel backfill or drainage mats. Show and detail drainage and backfill system in
wall section. Locate drainage pipe invert elevation below bottom of concrete floor slab
elevation |
| |
| 3. | Additional drainage pipes will usually be required near the top of
the below-grade wall at a point 5' to 10' away from the wall. Direct roof water or subsurface water
to drainage pipes using membranes and/or clay caps sloped away from the building to the drainage
pipe. Water diversion membranes should be detailed with fold (slack) for possible
settlement. |
| |
| 4. | Eliminate hydrostatic head wherever possible. Where a watertable is
present, install additional drainage pipes as may be required to draw down watertable at wall, below
floor, and through footing in coordination with the geotechnical, civil, and structural
consultants. |
| |
| 5. | Where drainage depends on mechanical pumping, provide emergency power
as well as structural provisions for buoyancy and lateral pressure. |
| |
| 6. | Slab-on-grade construction (where below-slab waterproofing is not
required) shall include a 4" minimum gravel layer for capillary break, an 8 mil polyethylene
moisture barrier (or equivalent) and a 2" minimum layer of sand over the polyethylene. |
| |
| 7. | Show and specify drainage backfill, drainage pipe and damp-proofing
(or waterproofing) at retaining walls. |
