Factory Mutual Global Standards

[Robert]

I'm not sure if this is the right forum to post this. I am designing an extensive vegetated roof (residential). The plan checker has asked for me to "meet Factory Mutual Global Standards for engineering and membrane testing.".There are many components involved (membrane, draimnat, root barrier, protection board, Class A overlayment, etc.) so am I correct that the membrane is the only item that needs to come from a company that has given it FMG compliance?

Also, with the engineering needing FMG compliance, does this mean that I need to redesign the assembly and all of its parts to an assembly that has already met the FMG standards? Where would I find those assemblies?

 

[cda]

Factory mutual

Are these houses or apartments??

http://www.fmglobal.com/research-and...al-data-sheets

Suggest you call them so they can direct you to what you need.

Might have to pay for the info

Yes it sounds like you have to meet FM standards for design

 

[Wayne]

They are requiring only FM Global certification? They aren't the only ones that do it. Any roof manufacturer can provide this data for the roof you want as well as standard details.

 

[cda]

Might need FM

1-35 Green Roof Systems

http://www.ci.berkeley.ca.us/uploadedFiles/Planning_and_Development/Level_3_-_Energy_and_Sustainable_Development/Factory%20Mutual%20Green%20Roof%20System.pdf

Suggest you ask the plan reviewer to make sure you get the right one and all you need

 

[Robert]

Thanks CDA. This is a single family home in Berkeley (I have looked at the standards you posted on their website). The pdf looks like a generic spec without any proprietary names and my assembly matches what is shown. It sounds like I need to get the membrane testing information from the roofing company and submit that, but the engineering has me confused. Of course our engineer has designed for the roof so not sure what else to provide.

 

[cda]

Thanks CDA. This is a single family home in Berkeley (I have looked at the standards you posted on their website). The pdf looks like a generic spec without any proprietary names and my assembly matches what is shown. It sounds like I need to get the membrane testing information from the roofing company and submit that' date=' but the engineering has me confused. Of course our engineer has designed for the roof so not sure what else to provide.[/quote']Just a SWAG

seems like the ahj just needs to see you meet all aspects of that spec. Suggest you reference different sections of it on the plans to show you have looked at it.

Good luck in Berkeley

 

[Robert]

I think you are right. SWAG?

 

[cda]

https://en.m.wikipedia.org/wiki/Scientific_wild-ass_guess

 

[SCBO1]

Just wondering,"through life," What is the typical dead load per square foot added to the roof when going green? SWAG will do?

 

[cda]

St Augustine or rye grass

I have no idea??? Sorry on the ahj side and do not do houses or structural

 

[mtlogcabin]

Since a roof garden is not within the prescriptive requirements of the IRC you will need to use the IBC

Live Load is 100 PSF

1606.1 General.

Dead loads are those loads defined in Section 1602.1. Dead loads shall be considered permanent loads.

1606.2 Design dead load.

For purposes of design, the actual weights of materials of construction and fixed service equipment shall be used. In the absence of definite information, values used shall be subject to the approval of the building official.

Type of soils, amount of moisture will be held by the soils, thickness of the soil. It all needs to be included in the dead load amount.

 

[Mark K]

Suggest that you confirm with the plan checker the code section he is invoking. My search suggests that when FM standards are listed that there is at least one other option that does not require FM certification.

 

[cda]

You might wonder through their web site to see what you can find

http://www.ci.berkeley.ca.us/greenroofs/