Step 6:
Compact the Sub Base

If you do not compact the sub base material properly it will eventually settle in a way that will cause irregularities in the surface of your putting green. These irregularities adversely affect the roll of your ball when putting. Remember that the plate compactor can be rented from any local rental facility.

• With your garden hose’s spray nozzle wet the sub base lightly. Do NOT saturate it.
• Now compact the sub base. To ensure good solid compaction, make sure to compact the sub base several times the length and width of the area.

If there are any small bumps, ridges, or irregular dips remaining smooth them out with your rack or shovel. Use a 2 x 4 to screed or level the base material. You may notice low spots or dips on your base. Chances are that you have a low spot on the sub base that needs to be filled.

Your main goal is to keep the surface consistently flat, smooth and solid.

• Adding undulations or contours is easy.
• Add additional base material to that area.
• Shape it with your rake until you have the desired contour and undulation.
• Compact that area with your plate compactor. Understand a 1 inch rise over 1 to 2 feet will add a lot of contour once the putting green is added.

The putting green turf is designed to fit like a glove to the surface. If you add too much slope to your sub base material the ball will roll very fast and may roll off your green.

A good basic guideline is for every 10 to 12 ft in the length of your sub base you will drop the slope 1 inch

To determine whether you have enough or too much slope or contour-- after the sub base material is completely compacted take a golf ball and putt on the sub base.

The ball will break the same on the sub base as it will when you install the putting green. Your sub base should be a minimum depth of 4 inches when compaction is complete.

Make sure the sub base is the way you want it. If you want to add or take away extra slopes or contours now is the time to do it. However, if you make any changes to the sub base then you must re-compact the sub base after the changes are made. Once the putting green and the infill is added it is difficult to adjust the contours of the sub base.