3.11 SPLICING

Splicing

Most walls require a splice because the footing/slab is a fixed dimension and so is the block. Therefore, in each wall, somewhere between the corners the installer will normally cut a block vertically to fit that walls proper linear dimension. There are 2 generally accepted practices:

1. The first and easiest method is to lay block to the same area in any wall and run a vertical seam bottom to top. With this method the installer can double check linear dimensions as he builds. The installer will need to brace horizontally across the seam both on the inside and outside of the block to strengthen the area for the placement of concrete. The bracing can be as simple as 1x4’s every course or two. After double checking the wall for linear dimension and plumb, the installer should put a brace on each outside corner to ensure said dimensions are maintained throughout the concrete placement. With this splicing method the installer can be sure linear dimensions are exact and all webs are vertically aligned in every wall.

2. The second method utilizes what Greenblock refers to as a “true splice” or “running splice” pattern. When using a true splice pattern, the installer should cut the block with a minimum two web overlap past any vertical joint. In addition, there should be at least one cut line past either last web. Greenblock ICF’s were designed to have 8 webs, 5 cut lines between each web, with 3 cut lines on either end - past the last web. (Please know that each end of the block has been formed on a cut line.) Down the center of each web is a cut line but we normally do not cut there.

We call a factory (non - cut) block a 3-8-3.
3 cut lines to the left of the last web on the left
8 webs
3 cut lines to right of the last web on the right

Therefore a ½ factory block would be a 3-4-3,
And a ¼ factory block would be a 3-2-3.

If you follow this counting system you can speed up construction and ensure correct walls.

• First - count the cut lines to the left of the last web to the left.
• Second - count and list the webs.
• Third - count the cut lines to the right of the last web to the right.
• Fourth - mark the counts on splices in the 1 • st and 2nd courses.

Example of a True Splice:

A true splice changes the web pattern. When we cut a true splice, we try to minimize the area in which the webs misalign. We attempt to keep the area where the webs do not line up to a 2’-3’ distance. Between the X’s the webs will line up every other course. (ie.. the webs will line up in courses 1,3,5,7… and 2,4,6,8…) From the outside X’s to the corners all webs should line up vertically.

Example of a Running Splice:

A running splice is where two blocks meet, and the webs retain their on center spacing. The on center web pattern for all Greenblock systems is 6”. A running splice does not change the pattern between webs. Installing one block with factory edges next to another block with factory edges creates a running splice. All webs should line up vertically in this wall.

NOTE: Always build from the corners to your splice area. Your splice on the 1st course should be repeated on all odd courses and your splice on the 2nd course should be repeated on all even courses.

When splicing, one end of the block will usually be a factory edge with at least one #3 cut line either on the left or right side of the partial block. Any block or partial block with 3 cut lines on each end is considered a partial block with factory edges. It will not affect vertical alignment of webs as long as it is installed next to blocks with factory edges. These are running splices.

When cutting a running splice you will normally have factory edges of 3 cut lines to the left and right of the last webs. Therefore a running splice might count 3-2-3 (3 lines left, 2 webs, 3 lines right) or a 3-4-3 (3 lines left, 4 webs, 3 lines right) > See TIP

Blocks with any other number of cut lines on either end will affect vertical alignment of the webs. These are true splices. There should only be one true splice in most walls. When cutting a true splice, if you need a 2 web, 3 cut lines on the left and 4 on the right, you would write 3-2-4. (left cut lines first, Count the webs second and right cut lines last).

	If you mark splices and cuts on the bottom two rows when you set up the splicing pattern, you can reference those numbers to cut the same pieces for the remaining courses. You do not need to recount on each course. When working in a team situation, precut pieces can be waiting or one person on the ground can feed block to another on scaffolding/staging. Cutoffs around the job site can be located rapidly for a splice area, thus eliminating the need to cut a full block, reducing waste and speeding up construction.

If you are using the splice count system and you correctly cut the necessary block, but it does not fit, then you have made a change somewhere in that wall and are advised to locate it and correct it prior to adding additional blocks or courses. (This will help keep the walls plumb.)

Using this simple system of web and cut line counting eases installation, especially at splices and when building through a team effort. (It also helps to reduce waste.)

TIP: To utilize partial block that has been cut off from a full factory block (3-8-3) combine partial block such as a 3-2-4 and a 2-2-3 to create a 3-4-3. (½ of a full block) In this manner you may further utilize your waste.

*Remember that the end cut lines when joined together are 1 not 2.