# 8" block firewall



## 6stringmason (May 20, 2005)

I did a search on 'firewall' but didnt find much.

Anyone have any info on 8" block firewalls? I'd like to know is an 8" block wall by its self fire rated for 3 hours, or does it need zonolite or something similar put in?


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## slowsol (Aug 27, 2005)

http://www.orco.com/tech_fire_rat.htm


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## fjn (Aug 17, 2011)

or http://www.nwcma.org/TekNotes/CMFireRes0205.pdf


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## dom-mas (Nov 26, 2011)

As FJNs link says, it depends on the block, which differs by region. I'd ask the manufacturer, or the supplier, they should have all the info


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## Tscarborough (Feb 25, 2006)

Normally a true lightweight 8" is 2 hour unfilled, 4+ hour filled. Make sure they do not want a UL certified fire rating as that has to be done for the specific batch of block used, and, as stated, check with your manufacturer for the relevant test results.


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## 6stringmason (May 20, 2005)

Thanks for the info guys. It will be standard block, not the light weights. 

I have some 12" and 8", and it doesnt call if zonolite is used, but says add an hour if it is. I'll call the local yard tomorrow.


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## fjn (Aug 17, 2011)

6stringmason said:


> Thanks for the info guys. It will be standard block, not the light weights.
> 
> I have some 12" and 8", and it doesnt call if zonolite is used, but says add an hour if it is.






As previously mentioned, be careful around that darn zonolite.


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## concretemasonry (Dec 1, 2006)

6string -

Check with County Materials (if there is anyone else left after buy-outs) and see if they have 8" block with a very thick face shell. They are pretty weak on anything technical but they may know.

For many years, many producers made an 8" block with a 2 1/8" face shell for UL certification, but sold the same unit without certification at a lower price because of the red tape for UL. In heavyweight/normal weight, it had a 3 hour rating and the lightweight was 4 hours with no core filling labor necessary for either weights.

Oldcastle may also have the same units since they have access to many more molds than County, but they may not be in stock. I know the boys in GB made the UL block at one time, but probably rented the molds from someone else. Bend/Oldcastle also made them years ago in West Bend, but who knows what is in stock in WI now.


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## Diamond D. (Nov 12, 2009)

I can't (won't) say one way or another, but back in the day we used 8" concrete block for all party walls, filled with vermiculite.

That's what was on the plan.
Today,??? Probably doesn't matter what you use, someone is bound to sue you.

02,
D


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## jomama (Oct 25, 2008)

concretemasonry said:


> 6string -
> 
> Check with County Materials (if there is anyone else left after buy-outs) and see if they have 8" block with a very thick face shell. They are pretty weak on anything technical but they may know.
> 
> ...


I'm starting to think that you're a closet "Cheesehead" ............:laughing:

Bend/Oldcastle/Northfield/whoeverbuysthem next doesn't make them here anymore I don't believe, but they're made at one of the Northfield plants in Northern Ill., in both 3 & 4 hour HW as I recall. I run into this issue once in a while with 8", and have found that we can usually just fill the cavity with sand to get to 3 hour. Pretty sure all you need is 5.02" total or something like that, and the State will sign-off on it. 

I did look for pretty extensively for Zonolite this past fall (even in your area 6string) and could find anything. Closest was Perlite, but I didn't want to pour it outside in this higher-end area, and we had to tooth-in a few door openings later in the same wall......


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## concretemasonry (Dec 1, 2006)

I am not a closet "cheese head". My wedge is purple with white horns when I wear it.

There are many ways to raise/increase the fire rating depending on the openness of the authorities. Since concrete does not burn it is just a matter of the amount of mass (equivalent thickness for block) what is put into the cores. Anything (grout, sand, vermiculite, perlite (the best and priciest) increases the fire resistance as long as the local authority approves the background tests. Even a good lightweight aggregate (expanded shale or pumice is great) if available.

In the Republic of WI, the left-overs of the old DLIHR still remain in some areas. When we supplied block for WI certifications, the owner of the testing lab was puzzled why the required such a low standard for LWT block (115 max pcf in WI when the rest of the world had a higher standard of 105 pcf max.), but he followed the standards since they had labs in WI - Codes and standards are always slow to change.


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## 6stringmason (May 20, 2005)

I got a price on some 8" lightweights with a 3 hour fire rating right from the plant. Pulaski concrete. 

No one around here sells vermiculite or perilite anymore. All the yards got it from County, and County quit carrying it.


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