Installation Instructions

Information and stairwell
dimensions for new construction
The stairwell for the Bilco basement door
should be built at the same time as the
house foundation. If foundation and stair-
well are poured concrete, build the stair-
well to about the height of the proposed
finish grade. Push Z-anchors or short
pieces of reinforcing rods into wet con-
crete. This allows for pouring a 4" cement
capping later. Waterproof outside of stair-
well walls as you do the basement. If
stairwell is masonry block, fill cores of
block with paper before pouring cap, or
cap the wall with solid 4" masonry blocks.
To construct stairwell to proper dimen-
sions for various grade conditions, first
determine the approximate height the
grade will be above the finished base-
ment floor. Then, refer to the construction
guide below. Find the range in which this
grade height falls. Read across to deter-
mine dimensions of the stairwell and the
size and dimensions of the Bilco base-
ment door and stair stringers to be used.
Page 7
Bilco Door Dimensions
Size Length Width Height
O 4'-10" 3'-11" 2'-6"
B 5'-4" 4'-3" 1'-10"
C 6'-0" 4'-7" 1'-7 1/2"
SL 3'-7 1/4" 4'-3" 4'-4"