Shear Failure:
- Improper sole plate anchorage.
- Improper mailing of shear element (i.e. plywood, gypsum board, stucco).
- Tearing of shear element.
Drag Failure:
- Missing/inadequate top plate straps.
- Insufficient top plate splice.
- Undersized top plate.
Potential Damage:
- Cracked finishes.
- Water intrusion.
- Ruptured plumbing and gas lines.
- Partial or total collapse of framing.
Common Problems:
- Grade slopes toward building.
- Inadequate waterproof membrane.
- No protection board.
- No extension of waterproof membrane above grade or over footing.
- No foundation drain.
- No gravel or filter fabric around drain.
- No waterproof membrane under slab.
Potential Damage:
- Efflorescence and water stains on walls
- Ponding against building and on basement floors.
- Moisture migration though slabs.
The Five Basic Elements For Waterproofing Below Grade Walls:
- Waterproof membrane
- Protection board
- Gravel Fill
- Foundation Drain
- Filter Fabric
Recommended Solutions:
- Slope the finish grade away from the building,
- Install a membrane under the concrete building slab,
- Provide a cant strip to transition the waterproof membrane at any 90 degree angle,
- Install ultraviolet protection for the above-grade waterproofing.
Common Problems:
- No drain installed.
- Drain installed, but no outlet for water.
- Drain installed without proper gravel and filter fabric – leading to clogging.
- Drain installed too high – allowing water pressure to build up below the drain.
Potential Damage:
- Excessive/unsightly leaning (rotation).
- Collapse.
- Excessive wall cracking.
- soil/pavement buckling in front of wall.
- soil subsidence behind wall.
Proper Solutions:
- Install continuous drain pipe embedded in gravel and wrapped in filter cloth.
- Drain pipe should be installed below the finish floor/grade and above the bottom of the footing.
- There are generally two types of hold downs; the embedded strap and the anchor bolt hold down. Their function is to prevent the end of a shear wall from lifting off the foundation.
Proper Construction:
The following are the principal elements necessary for hold downs to function properly:
- Correct size of anchor bolt and/or hold down.
- Attached to the end stud by sufficient nailing or bolting.
- Nut tightened sufficiently on anchor bolt.
- Bolt holes drilled to proper size.
- Strap or bolt properly imbedded into foundation.
- Positioned properly at the end of the wall, adjacent to the end post.
- Positioned at the proper distance from the edge of the foundation.
Common Problems:
- Missing hold down.
- Undersized hold down.
- Improper location of hold down.
- Improper installation of hold down.
Potential Damage:
- Cracked finishes.
- Water intrusion.
- Ruptured plumbing and gas lines.
- Partial or total collapse of the framing system.
- Personal Injury.
