Installation Guide
Page 3
STEP 3: Door Installa-
tion: CAUTION: Doors 
are heavy until gas spring 
operators are installed. 
Two people may be re-
quired for door assembly.  
Install right door by holding it 
vertically over the right side 
piece as shown in Figure 
#3. Position the door so 
that the door hinges t into 
the hinge brackets that are 
welded onto the side piece 
as shown. Line up the holes 
in the hinges with the hinge 
pivot holes in the brackets 
and insert the 5/16” x 1-1/4” 
hinge pins and cotter pins as 
shown. Install the left door 
in the same manner.
#3
Hinge Pin
Cotter Pin
Install hinge pin so that head of pin is facing towards the 
house as shown (Left door and side piece shown)
IMPORTANT! An interior 
door at the bottom of 
the steps is required to 
prevent heat loss and 
reduce condensation.
Figure #4
A: Upper Spring Bracket B: Lower Spring Bracket
A
Push
Push
IMPORTANT: Install Gas Springs as shown with 
larger diameter portion of spring on top. 
Side piece 
stiffener
Lower 
spring 
bracket
STEP 5: Painting the BILCO basement door:
BILCO Basement doors are supplied in either a red oxide primer or powder coat paint nish. If your door has a powder coat nish, no additional 
nishing is required.
IM PO RTANT: Doors supplied with a primer nish must be painted within forty-ve (45) days of installation. BILCO requires the use of 
an exterior alkyd base enamel.  For best results, carefully follow the directions on the paint label and apply one thin coat of paint followed 
by  a  second  coat  on  both  the  exterior  and  interior  primed  steel  surfaces  of  the  door.  Two  quarts  should  be  sufcient  to  coat  the  entire  door. 
Application of paints that are not alkyd based may void product warranty.
STEP  4:  Gas  Spring  Installation: 
With the BILCO basement door frame 
solidly anchored, the gas spring opera
-
tors can now be installed. Attach lower 
spring bracket to side piece stiffener 
(on side of stiffener facing top step) 
using (2) 5/16” x 1/2” bolts and lock 
nuts as shown in Figure 4B. Attach 
ball fasteners supplied in bag with 
gas springs to lower spring bracket 
and upper spring bracket as shown in 
Figure #4A & B. Note: Make sure the 
that ball portion of the fastener is 
facing towards the house on both 
brackets. With fasteners securely 
tightened and door in the open posi-
tion, push gas spring onto lower ball 
fastener as shown in Figure 4B until 
you hear it snap into place. Position 
and snap other end of gas spring onto 
upper spring bracket shown in Figure 
4A to complete spring installation. 
Repeat process on other door leaf.
A
B
B




