Edit Assembly

[Anonymous]

I am trying to edit a roof assembly. My top layer is a roofing membrane. I give the roofing membrane a thickness and try to save and I get an error message saying that it needs to be 0" thickness. I set the thickness to 0" and I get an error message saying that it needs a thickness. How do I get pass this Catch 22?

[melarch]

You cannot set the Function for that layer to Membrane. Membrane layers are considered to be infinitely thin (i.e. visqueen, building paper, etc) where the thickness is measured in mils. Membrance layers must be set to ZERO, while all other Function set layers thicknesses must be set to anything but ZERO. Set the top layer to Finish 4 or 5.

Mel Persin, AIA
AEC Technology Consultant
Technology to Visualize and Realize Solutions
Modeling for the Future/Drafting in the Present/Building on the Past

[iamian33]

I realize that this is an old posting, but I am having this same problem. 

If I set the Vapour Barrier = membrane layer = 0 thickness

==> "There myst be at least one layer with non-zero thickness"

??? curious response since the thickness is set to 0

If I set the Vapour Barrier = membrane layer = 1.6mm thickness

==> "Error" Row _: 'membrane layer' function requires zero thickness"

??? frustrating, but it won't allow me to set is to 0 (or 'zero')

The only thing I have found that I can do is not use the Membrane Layer function and call my vapour barrier a Thermal/Air and give it a minimal width of 1.6mm. 

How do I address this glitch?  Is it me or the software?

Ian

[Alfredo_Medina]

The first error message: "There must be at least one layer with non-zero thickness" occurs if the membrane layer  with zero thickness is the only layer in the wall type.

The second error message: "Error" Row _: 'membrane layer' function requires zero thickness" occurs when one of the layers, designated as membrane layer, does not have a zero thickness.

In summary, you need more than one layer in the wall type, if you want to have one of them as a membrane layer with zero thickness; and the other layer must have a value higher than zero.

[jkg]

I had the same problem. I did have two other layers in my wall definition. One was 5/8" sheathing and the other was a 1 1/2" stud (stud on side).  I could not make anything work until I tried it again and deleted the membrane layer. Then it magically worked. Nothing else was changed. It seems like a glitch.

[JohnCubed]

Yes - as with all Autodesk products, Revit is full of glitches.