For about 2 months, this was how you got to the sliding glass doors on the patio - you had to cross the board 'bridge'!  To start the plumbing in the basement, first we had to cut a hole in the basement wall.  So, we made 2 templates out of 3/4" plywood, and cut holes for all the pipe.  The hole we cut into the basement was 38" x 38"! Then we rented a concrete cutting chainsaw from the local rental center.  Amazing the things they rent out!  We marked off the hole, hung tarps in the basement, and started cutting. Here's the view from the basement.  Note that the saw runs wet - and the spray of wet concrete slurry went everywhere!  Thank goodness for tarps! The saw was heavy, so Mike and Rocco took turns.  You would think that when you got the hole cut, you would be done!  Not true!  Now you have a big loose chunk of cement in the hole - weighing several hundred pounds - it won't just fall out on it's own. 'One problem they had was getting the bead filters into the basement - as they wouldn't fit through the narrow basement doors.  But - they had a HUGE hole - so they just stuffed the filters through the hole!' Mike and Rocco Jackhammered the lose chunk out.  Not too hard if it's done the way it's intended - vertically with the weight of the hammer doing the work!  Turns out it's MUCH harder horizontally!  Poor Mike trashed the nail on his little finger - the only accident in this pond construction! (It healed perfectly - but he doesn't like Jackhammers!) Once the hole was cleaned, we put the templates on either side, and passed some rigid PVC through.  40+ pipes!  It was designed so that the only pipes in the frost zone were ones that would be turned off for the winter.  All the rest are well protected. Then, we filled the area around the pipes inside the templates with concrete.  We actually made the basement wall another 8" thicker than it was, and connected the old concrete to the new concrete with some leftover rebar.  While the concrete was being poured, a vibrator was used to make sure there were no air holes! Then we started connecting the pipes!  What fun - trying to figure out which line ran to where!  We marked them, but some were still a mystery!  Karen created a final map of the pipes, and keeps a copy in the computer and pond files for reference. We started working from the bottom up.  The whole area with the pipe was insulated with several thicknesses of the special driveway insulation.  As the pipes were connected and tested, we filled that row with screenings (a mix of stone dust and very small rock). We finished connecting all the pipes outside, wrapped the top with more insulation, and completed the screenings.  Finally - we could walk across this area without a board bridge!  And - the screenings made an excellent base for the patio!