In this video, we’re going to cover how to construct gables out of ICF block. In our example, we’re going to construct cathedral roof style cables on a 6/12 pitch, meaning every foot our gables will raise 6 inches. For a cathedral roof, the gable is constructed to align with the interior wall, but other styles will have different design requirements.
You can construct your gables either as one complete piece, or in two halves. However, if a common seam is already present, then we recommend constructing your gables in two separate halves, and continuing your common seam all the way up the middle. Many of the cut off angle block can be adjusted to fit the other side of the gable. We also recommend stacking, measuring, and cutting your blocks on the ground, and then either reassembling them on top of your wall, or lifting the completed gable into place. To begin, stack enough block to reach the height you’ll need for your gables. It’s very important that the nailers on your gable align with the rest of the wall.
Also make sure that your vertical joints have at least eight inches of overlap from course to course. Next, number each block to make reassembly much easier and ensure no mistakes are made, but be sure to place the number far enough on the interior of each block that you do not accidentally cut it off when making your cuts. Next, if you plan on lifting your gables into place, it can be helpful to glue the blocks together at this point. After you have measured your gables, set your chalk line. Now you’re ready to make the cut.
After you’ve made the cut, trim back any plastic that is peeking out above the foam, but try not to completely remove any of the webs as this could damage the reinforcement of the block. Next, we’ll measure out the vertical nailers that we’ll use to give our top plates a place to attach to. We’ll want to place two for each top plate,
and space them out two to three feet onto the BB HardPoints. Using shorter lengths of sill plates and setting them as you pour helps to ensure good consolidation of the concrete.
Next, we’ll test stack our top plates to make sure we’ve measured out our nailers correctly, and to mark the placement of our j bolts. We’ll place three j bolts on each top plate board. Be sure to offset each j-bolt to combat the warping of your top plate as it dries. Also be sure to double check that your j-bolts fit cleanly in between the webs. As you pour the wall, set your top plates into place and secure them with the nailers.
This is our recommended way of constructing ICF gables for your structure. Please contact us if you have any further questions.