3.14 SETTING THE FIRST COURSE

Prior to setting the first course of Greenblock, the installer should double check the layout dimensions and snap chalk lines on the footing or slab. If working on a slab and prior to laying the first course of Greenblock, installers often stand any specified door bucks in position, plumb and secure.

The next action is to determine where to begin laying the Greenblock. If you have step footings and they were designed and poured to Greenblock dimensions then you will normally begin at the lowest elevation and work up.

Sometimes when footing steps are not compatible with Greenblock dimensions the installer will need to determine which elevation is best to begin laying block on. If you begin on the wrong step you might end up trimming the block laid on the next steps or for the majority of the project. Instead, you may want to lay block on the main level and work backwards calculating each step down to the lowest level. In this manner you will know what shimming will be required at each level to make the main level interlock. Then lay block at the lowest level and come back up the steps bringing all stepped levels up to the main elevation. The installer should attempt to keep block cutting to a minimum reducing waste and labor.

Another way to handle steps that aren’t compatible with Greenblock’s height dimensions is to run vertical seams as required.

Installers generally begin by laying block on the slab/footing from the corners to a location in the wall where you will perform a splice. Since both the block and the slab/ footing are fixed dimensions most walls will have a splice area.

Alignment of the block to the snapped chalk lines on the footing or slab is usually maintained with glue, kick plates, metal channeling or the most common, compatible foam spray. This will be explained in 3.15.

At the first corner on the chosen level, place a right corner. At the second corner – place a left corner. Cutting corner blocks is not recommended, cuts should be performed, as often as possible, on standard blocks. If corner block cutting is required, additional bracing/gluing may be required. Continue alternating left and right corners placing a left or right block at each corner. This assures an even number of lefts and rights are used when building each course so you have the correct amount of each necessary for the top course. When the corners are in place, begin laying blocks in-between. Beginning at one corner - lay one block at a time. Place each block over the footing/slab dowels. Continue laying blocks towards the splice area. the block comes together, be sure it is aligned along the snapped chalk line(s) before scribing a piece to fill in.

If using the overlapping splice pattern be sure to cut on a cut line. Mark the block with cut lines and webs and install. If using the vertical seam you may cut off the cut lines. This will be the splice area for that wall. Most walls have one (1) splice area. Splice areas should be arranged at door openings, under and above window openings, behind shower walls, in utility/mechanical rooms, at interior intersecting wall areas or slightly away from a corner if possible. When you reach the area where the block comes together, be sure it is aligned along the snapped chalk line(s) before scribing a piece to fill in.

Cut the forms as needed when coming to a door or window. Cut lines are nice guides around these openings, but you do not need to cut on them exactly around windows and doors. Do not cut the block tight against the bucking. Leave approximately ⅛” to ¼” so the bucks can be adjusted. (You can foam prior to pour to fill the gap. Foaming will also help hold window bucks and block around the windows as a solid unit.)