Vermiculite in CMU

[Inspector 102]

I have a contractor using 507.5 for a fire wall application. He has proposed D-2 block with vermiculite filled cells. I have tried to find out at what height vermiculite needs to be installed to ensure proper fill. The total wall height is 16' and I do not think they can simply pour it in at the end of the job before the bond beam is installed. Any guidance on acceptable application would be provided. This appears to be a UL 905 installation, but again, no guidance on fill material that I can find.

 

[FyrBldgGuy]

The listing detail is required to show the specific fill requirement for the rating. Ask the designer for the listing detail.

 

[brudgers]

I have a contractor using 507.5 for a fire wall application.

You allow contractors to design firewalls?

 

[conarb]

I thought Vermiculite contained asbestos, wasn't that what the W.R. Grace lawsuits, superfund, and criminal charges were all about in Libby Montana?

 

[mark handler]

I thought Vermiculite contained asbestos, wasn't that what the W.R. Grace lawsuits, superfund, and criminal charges were all about in Libby Montana?

Vermiculite is a 2:1 clay, meaning it has 2 tetrahedral sheets for every one octahedral sheet. It is a limited expansion clay with a medium shrink-swell capacity. Vermiculite has a high cation exchange capacity at 100-150 meq/100 g. Vermiculite clays are weathered micas in which the potassium ions between the molecular sheets are replaced by magnesium and iron ions.

 

[Inspector 102]

To clarify, the engineered plans indicated 8" D-2 2-hour fire resistive CMU w/vermiculite filled cells, 3-hr fire resistive wall. My concerns is that the vermiculite, or equivilent material, be filled into the cells properly. Because I am limited in knowledge on the installation method, I was asking if there is a standard for this application. Is there a normal level that the fill material should be added? Every 4 feet of block? 8 feet? The contractor has done good work in the past, but the owner I do not really trust completely. I will say that when there was a concern on a soil issue, the owner, engineer, soil engineer and construction foreman were all on site reviewing the soils at the same time. Made me feel kind of unneeded at the time.

 

[Mac]

Is there an ICC-ES report?

 

[Examiner]

From Grace web site Zonolite.

Installation

Preparatory Work

Block joints at pilasters or other vertical members should be mortared, and weep holes should be filled with glass fiber, rope or copper screen to prevent insulation leakage.

Method

Insulation should be poured from the bag or hopper directly into the concrete block core or wall cavity. Pours can be made at any interval, but not to exceed 6.1 m (20 ft) in height, without requiring bridging. Rodding and tamping are not required.

If it is a stack bond filling from the top should not be a problem. A running bond in my opinion should be filled with each course.

 

[brudgers]

If it is a stack bond filling from the top should not be a problem. A running bond in my opinion should be filled with each course.

The voids in the CMU align the same either way.

 

[Inspector 102]

The plans indicated there is a bond beam at 8' and 16'. I guess as long as I witness both fills, they can pour at each interval. Thanks for all the help.

 

[brudgers]

Have them knock out the bottom of a few cells. That way, you will know it is full when the vermiculite comes out the bottom.

 

[conarb]

Masonry construction requires Special Inspection:

1704.5 Masonry construction. Masonry construction shall be inspected and evaluated in accordance with the requirements of Sections 1704.5.1 through 1704.5.3, depending on the classification of the building or structure or nature of the occupancy, as defined by this code.

 

[Examiner]

This darn cold is not allowing me to think properly. What was I thinking that the cells did not line up.

 

[brudgers]

This darn cold is not allowing me to think properly. What was I thinking that the cells did not line up.

You were just looking for a reason to say "no." It's a job hazard, but there's a twelve step program.