How to measure your tunnel for a new sheet
At ground level, measure from the corner, shown in our diagram as 'A', on the front of the tunnel to the other corner on the front of the tunnel marked here as 'B'.
Measure the total length of side C
Add them together and that is the LENGTH of the sheet you will need.
This allows plenty of cover to go to the door uprights at both ends and to reach down to the door header at each end.
To find the WIDTH of the sheet you will need to use the chart below
Sheet size calculator
PLEASE NOTE: This fits 99.9% of all commercially manufactured tunnels however there are always exceptions and XL take no responsibility for a sheet incorrectly ordered. So, to be belt and braces sure, we recommend that you measure over the top of the hoop from fixing to fixing to give you the width of sheet and then add 1 length of your tunnel to 1 width (at ground level) of your tunnel to give you the length of sheet you need.
You also need to allow approximately 1 metre each side of your sheet if your fixing method is ground buried in a trench.