Measuring the distance: In order to determine where to cut the circle that the radiator pipe will go through, we should first measure the distance from the wall to the radiator pipe with a ruler or set square and draw a line on the plank with a pencil.

Measuring vertically: To find the central point of the pipe hole, we should place the ruler/ set square vertically to the pipe, and draw a line on the plank with a pencil. The central point will be where the two lines intersect.

Making a hole: Having determined the central point, let's make a hole around it with a punch drill. The circle should be large enough for the radiator pipe to go through.

Cutting the plank: After making the hole, we can now divide the hole by cutting the plank along the line drawn, with a saber saw.

Placing the plank around the radiator pipe: We can now place the plank with both hands, which is cut into a semi-circle, beside the radiator pipe. If the circle that we cut is larger than the radiator pipe, we can fill the gaps with silicon (it is advised not to apply silicon towards the wall side of the pipe, since this might prevent the parquet to expand and cause swelling).