Miniature Golf (Putt Putt) Course

My son, Zach, and I were looking for a summer project to build. It was a toss up between a kayak and a miniature golf course. Zach said we'd use a golf course a lot more than a kayak, so we decided to build a ten hole miniature golf course. We designed the course so it would not take up a lot of room and would use as many materials that we had on hand. The basic design is two 4' by 8' courses connected together by a child's metal slide as a causeway with a third 4' by 8' course lower, (we live on a hill). The ball rolls from the upper levels to the lower one by 2 inch pvc pipes from holes on the two higher courses. We built obstacles that can be moved from hole to hole. We built our courses on three extra in ground swimming pool panels that were leftover when we installed our pool. 
You could just as easily frame up the courses with 2 x 4s and plywood as the deck subfloor. I'll detail the construction in the following steps. 

Purchase or scrounge the material. 
2x4s Pressure treated (unless you have 3 swimming pools panels laying around)
4x4s Pressure Treated
3 4 foot by 8 foot 1/2 plywood
indoor/outdoor carpet
Metal Kid's slide
Indoor/Outdoor Adhesive
4 inch diameter PVC pipe
2 inch diameter PVC if you want to have a course lower to putt down too
various obstacles
3/4 inch plywood

We had quite a few things laying around the house.  The biggest expense was the indoor/outdoor carpet.  We spent about $150 U.S. dollars in 2010 to build this.

Build 4 by 8 rectangles with pressure treated 2x4s.  Nail the base together with 16 D nails.  Put the floor joists 16 inches on center.  Nail the 4 x 8 piece of half inch plywood to the bases with 6D nails.  Decide where you want to put your holes.  We had a total of ten holes for our 3 section golf course.  Trace the outer edge of a piece of 4 inch PVC where you want the holes and use a jig saw to cut the circles out. 

For each course, we dug 4 post holes to the frost level (one post hole for each corner of the rectangle).  We then inserted pressure treated 4x4s into the post holes and filled the remaining area of the holes with concrete.  We left about 3.5 inches of 4x4 out of the ground.  Make sure the 4x4s are level with each other. 

Place your rectangular course on top of the 4x4s and after ensuring level - nail the course to the 4x4s.  Cut 4 inch long PVC (4 inch diameter) and place in the golf holes that you previously cut out with the jig saw. 

With a caulking gun, put indoor/outdoor adhesive onto the deck of the courses.  Use a trowel that has grooves in it to spread the adhesive onto the deck.  Cut the carpet to size before putting the glue down!  After gluing, put the carpet on the deck.  Use a roller to make sure the carpet is flat and pressed down onto the glued deck.  We didn't have a roller, so we made one out of 4 feet of 4 inch diameter PVC and filled it with concrete and let it harden. After 24 hours, you can carefully cut the holes out of the carpet. Once you're finished putting on the carpet, nail pressure treated 2 x 6s around the perimeter of each course so the ball stays in play and you can bank the shots. 

If you have a slide or other means to connect multiple courses together, do that now.  We also put a 2 x 6 pressure treated wood around the perimeter of the courses so that we could have a means of keeping the ball from leaving the course and for banking shots.  Use your imagination to create obstacles.  Our course is baseball (Cleveland Indians - go Tribe) based.  Whatever obstacles that you create, cut a 4 inch diameter circle out of 3/4 inch plywood and adhere to the bottom of your obstacle.  That way you can insert the obstacle into the 4 inch diameter PVC holes and move them at will. Then enjoy many hours of playing miniature golf!