How to Determine the Proper Measurements for Your Dock Seal

The key to purchasing the right loading-dock seal for your operation is to measure accurately. And the first thing to take into consideration is the grade of your loading-dock driveway, since this affects the recommended dock bumper and dock-seal projection. Here's a simple guide to determining the proper measurements.

LOADING-DOCK DRIVEWAY DECLINE & INCLINE APPROACHES

All recommendations are based on the percent of grade. To determine it, use this formula:

% of grade = Rise divided by Length x 100

"Rise" refers to the difference in elevation between the dock and a point (generally 45' to 50') in front of the dock.
"Length" refers to the actual distance on the driveway over which the rise is measured.
How to Measure Loading-Dock Driveway Decline & Incline Approaches
 
By properly measuring the slope of the loading-dock driveway, we can provide adequate dock-bumper protection
 and taper foam-pad seals to avoid over- and under-compression.
 

  Chalk-Line & Level Method

For this method, you are required to use an empty chalk line (one with no chalk) and a line level. Both of these items can be purchased
from most hardware stores.
 

 Step 1  Measure the dock height and note it on your survey sheet.

 Step 2  Hook the end of your chalk line somewhere on the top of the dock.

 Step 3  Walk your chalk line out from the dock until you are 50' away from the loading dock.

 Step 4  Put the line level on the 50' mark on your line.

 Step 5  Level the line and measure the distance from your line to the ground. This will be the A dimension.

 Step 6  Use the formulas below to calculate the rise or drop in the driveway.

DECLINE (rise) = Dock Height - A

INCLINE (rise) = A - Dock Height

 Step 7  Refer to the charts below for the proper dock bumper and dock seal size.

 
Once the percentage of grade is determined, refer to the chart below for the dock-bumper and dock-seal
projection recommendations:
 

Decline Approaches

Percent of Grade

Bumper Projection

Dock Seal-Top

Dock Seal-bottom

Level

4 "

10 "

10 "

1 %

5 "

10 "

11 "

2 %

6 "

10 "

12 "

3 %

7 "

10 "

13 "

4 %

8 "

10 "

14 "

5 %

9 "

10 "

15 "

6 %

10 "

10 "

16 "

7 %

11 "

10 "

17 "

8 %

12 "

10 "

18 "

9 %

13 "

10 "

19 " 

10 %

14 "

10 "

20 "

11 %

15 "

10 "

21 "

12 %

16 "

10 "

22 "

 
Since incline approaches slope away from the building, the dock bumper projection should remain at 4",
but the dock seal projection still needs to be addressed. Once again, take the percentage of grade
and refer to the chart below for projection recommendations:
 

Incline Approaches

Percent of Grade

Bumper Projection

Dock Seal-Top

Dock Seal-bottom

Level

4 "

10 "

10 "

1 %

4 "

11 "

10 "

2 %

4 "

12 "

10 "

3 %

4 "

13 "

10 "

4 %

4 "

14 "

10 "

5 %

4 "

15 "

10 "

6 %

4 "

16 "

10 "

7 %

4 "

17 "

10 "

8 %

4 "

18 "

10 "

9 %

4 "

19 "

10 "

10 %

4 "

20 "

10 "

11 %

4 "

21 "

10 "

12 %

4 "

22 "

10 "

 
Need further help calculating your dock-seal needs? Contact the Dock Seal Pros by email or at 260.745.161.
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