Roof structure errors

[J. Grouchy]

I'm getting two contradictory errors when I try to create an EPDM roof system.

**see attached**

When I do as one error message tells me, I get the other.

[bowlingbrad]

I've seen this too. It should say something like membrane layers cannot exist outside of the core (or something like that).

[Scott D Davis]

The 'membrane' part of the roof is actually a finish catagory. Set it to Finish 4 or Finish 5. "Membrane" as a layer-type is intended for zero-thickness items such as Tyvek house wrap, which is so thin, it's not shown in a layered assembly.

[J. Grouchy]

The 'membrane' part of the roof is actually a finish catagory. Set it to Finish 4 or Finish 5. "Membrane" as a layer-type is intended for zero-thickness items such as Tyvek house wrap, which is so thin, it's not shown in a layered assembly.

I did it this way...but how do you explain the contradiction? One says it has to have thickness...but when I give it a thickness it says it can't have a thickness.

[iru69]

I did it this way...but how do you explain the contradiction? One says it has to have thickness...but when I give it a thickness it says it can't have a thickness.

Layers that have a function of "Finish" need to have a thickness. Layers that have a function of "Membrane Layer" cannot have a thickness.

If you want your membrane to have a thickness, the function cannot be set to "Membrane Layer".

If you want your membrane to have zero thickness, the function must be set to "Membrane Layer".

What I think Scott was saying is that even though architecturally you may think of your roofing membrane as being a "Membrane Layer", it's really a "Finish" layer. The function "Membrane Layer" is reserved for items such as building wrap that have essentially zero thickness.

HTH.

[Scott D Davis]

Also, "Face Layers" must have thickness. (Your second dialog box). Face layers are anything exposed either interior of exterior. You were trying two things: 1., to have a membrane have a thickness (it cannot) and 2., trying to have a membrane on the Face (it cannot, because face layers need thickness, membrane layers cannot have thickness.)

Make sense?

[iru69]

Also, "Face Layers" must have thickness.
I was going to mention that, because that's what I remembered as well - but then I tested it out just to make sure - and low and behold I *was* able to use a "Membrane Layer" with zero thickness as a face layer. Did something change in R8 or is it just inconsistant?

[beegee]

>>. Did something change in R8 or is it just inconsistant?
It can be done in R7 also.