Brick Heat-Sink Greenhouse Walkway

Down the center of the greenhouse floor is a walkway of bricks.  We were able to get the bricks at no cost, so we used 12” bricks.  But, any type of material that will absorb heat from sunlight and serve as a walkway will work.  The walkway is set in sand and is insulated on the sides and underneath with a layer of plastic sheet.  The walkway is intended as a heat sink which absorbs heat during the day, and releases heat into the greenhouse at night.  This helps to keep the temperature inside just above freezing.  This brick heat sink makes a big difference in plant survival when the outside night time temperature gets very cold.  The plastic sheeting is a barrier underneath, which insulates the bricks from the ground in order to reduce the heat absorbed by the bricks from bleeding into the ground, instead of radiating into the interior.  Between the walkway and the front (South) wall and back (North) wall, are the planting beds.
The picture in the picture shows the brick walkway.  The procedure for putting in the walkway is as follows.  Two 2 x 4s are leveled with a bubble level on the sides of the walkway area.  Then a leveling board shown at the top of the picture rides on the 2 x 4 s, and levels the sand in between them, which the bricks will sit on.  But, first the plastic is laid down on top of the sand and the bricks sit on top of the plastic barrier.

Before the brick is started, a design for the walkway should be decided.  This walkway is just a simple alternating brick design.  The first bricks in the first, third, and fifth rows should be cut in half, so that the rows have alternating seams.  A circular saw with an abrasive blade, or diamond impregnated blade can easily be used to cut the bricks.  The brick walk is stopped two feet from the opposite wall, which will leave enough space at the end of the walkway for planting.
 
To extend the growing season as much as possible, we grow many things in our greenhouses and are able to get more crop rotations every year.  We are also able to start the vegetables for the garden earlier and plant the seedlings when they are older, which helps the garden vegetables reach maturity before the growing season is over.  By using the greenhouses to extend the growing season, so that it starts earlier and ends later, we can eat fresh vegetables over a much longer period of time.  This greatly reduces the amount of food that we have to preserve in order to have it throughout the rest of the year.

Brick Walkway for Greenhouses