CMU- 2 core detail from autodesk

[thomas.denney836893]

I'm cringing at my own stupidity for asking this question already, because I know the answer is going to be paired with something like "You should have learned that in school!"

The CMU- 2 core detail component has a 1/16" inch gap at the top and bottom of the joint thus making it look as if the joint curves on either side are just floating in vacant space.

Can someone tell me why?

[Steve_Stafford]

You didn't mention which family you are referring to, there are three for the CMU-2 Core (Top, Section and Side).

I'll go out on a limb and guess that you are referring to the "Top" family. The overall dimensions of CMU is generally 3/8" less than their nominal dimensions. That means 8 x 8 x 16 CMU will actually measure 7-5/8" x 7-5/8" x 15-5/8" when you put a tape measure on one. The tolerance for this will vary by manufacturer to some degree. It's the same situation as you'll find with manufactured wood stud/joist sizes, nominal vs. actual.

The detail component is representing the "actual" dimensions in this case.

When we use them we'll have to decide which edge is meant to align with other things we are showing in the detail, or possibly centered between other materials.

[thomas.denney836893]

Actually, I was referring to the SECTION. Sorry I did not specify.

Yes, I am aware of the Nominal vs. Actual dims, and that they are drawn to actual, thank goodness for this!

Taking a second look and having applied the THIN LINES and looked at them with line-weights "on" I am guessing it is to help the detail look better. The 1/16" is an allowance for the thickness of the lines? If this is the case then why is this one of the only instances I've found of this aesthetic consideration being taken into account???

[Steve_Stafford]

Yes, probably. The masking of the "grout" would affect the underlying CMU filled regions and whatever element is beneath it.

[Mike L Sealander]

I think it is important to realize that while the Factory gets a lot of things right, the gap in the masonry family items is not one of them. I've noticed this, too. These families can be improved. That said, I use the ones out of the box, with a couple small modifications.