Add hanger

The next step is to add the big hole to one of the hollow cores. Since the hole is the same width as the slab, we need to support the slab somehow. To do that, we are going to use the hanger. 

Figure 1. Holes in the hollow core slab.

Go to IMPACT - Elements - Insert hanger to start the command. 

The command requires us to select some things. It's important to select the things in the right order. 

1. Select slabs to support - select the slab or slabs that should get shorten because of the hole. Click 'Finish'.
2. Select supporting slabs - select the slabs next to the slab(s) that should be shorten. Click 'Finish'.
3. Specify first corner - select one of the corners of the hole. In this case, lower left corner will be selected. 
4. Specify other corner point - select the opposite corner, in this case top right of the hole.  

Figure 2. Selection for insert hanger.

The dialog for hangers will open. Select 'HCS19' from project level. End with 'OK'. 

Figure 3. Select hanger definition.

The hanger will now be added to the hollow cores, and one of the slabs will be shorten so the hole will appear. 

Figure 4. Hanger added.

Next: Draw recess