Especially that paper on the gypsum.
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This argument is along the lines of drip leg vs. sediment trap. There are arguments out there both ways but no definitive answer that I’ve been able to find. I call out B-vent closer than 1" to drywall, as I would assume most inspectors do. I figure that the gypsum rock itself might not ignite, but the paper can.
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Certainly wouldn’t make sense to use a combustible material as a fire separation or as part of a firewall.
An old time plumber thought he could solder a broken water pipe in a wall about 20 years ago. I heard him yelling and came up from the basement.
His torch started a fire in the wall and I spent the next 10 minutes breaking up drywall with a hammer to stay in front of the fire before the fire department came.
If you think drywall isn’t combustible you are an idiot.
Ahh now you’re taking about fire rated gypsum. Not the same animal. By the way the stuff still lights up which is why it’s fire rated and not fire proof.
The paper will burn off very quickly. It’s the middle gypsum part that makes it a firewall.
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Well, what about FPE stab lok panels? We all know they have a history of problems and not tripping. If the breakers are never overloaded and there is no short on the circuit, the breaker would never fail and there would be no fire right? I mean we’ve all seen FPE stab lok panels that have been at a house for 40-50 years and there is no burning or any visible evidence of a problem, but the problem is still inherently there.
There are just a lot of things in electrical that could become problems but very rarely show up at inspection because the equipment haven’t been exposed to what it is designed to do. This boils down to if the problem only happens 1% of the time is it still a problem?
Take this for example:
On a lot of new construction in my area, the electricians wire the EGCs to bus bars that are screwed into the panel and rely on the bonding screw to the panel to provide the effective ground fault path. Usually done this way to separate the grounds and neutrals and make the panel look nice workmanship wise. Technically, it works and meets code and all that when everything is installed properly, but to rely on one screw for the effective ground fault path of every grounded circuit is a very stupid idea. I’ve found way too many panels where the hole for the bonding screw is stripped. This basically renders every grounded circuit in the house useless, but then again it could stay this way for 40-50 years and nothing happens if the EGCs don’t get used, which most of the time they don’t. They are there just in case something bad happens.
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Seen many drywalls left intact after fires. Just softened by the moisture.
They must have skipped the magic drywall on this beauty. Should have got the ACME non combustible stuff.
The damn wood is still standing but no magic drywall!
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A material can be combustible or flammable but also fire rated. Wood garage doors are an example. A solid wood door is an acceptable barrier between a garage and living space because it will impede the spread of fire compared to other types of doors. Drywall is required between attics of apartments/condos and also between garage attics and living space attics to slow down the spread of fire from one space to another. Fire rated materials don’t have to be non-combustible.
Here is the 2018 IRC section for reference:
R302.5 Dwelling-garage opening and penetration protection. Openings and penetrations through the walls or ceilings separating the dwelling from the garage shall be in accordance with Sections R302.5.1 through R302.5.3.
R302.5.1 Opening protection. Openings from a private garage directly into a room used for sleeping purposes shall not be permitted. Other openings between the garage and residence shall be equipped with solid wood doors not less than 1 3/8 inches (35 mm) in thickness, solid or honeycomb-core steel doors not less than 1 3/8 inches (35 mm) thick, or 20-minute fire-rated doors, equipped with a self-closing or automatic-closing device.
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Wood blocking has been used to slow fires for years… the key part here is SLOW a fire. Plenty of firestopping can burn.
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Standard drywall is neither fully combustible nor non-combustible. The paper covering is considered combustible, but the gypsum core is considered non-combustible. Here is it straight from the 2018 IBC definitions:
The gypsum core is what provides the fire rating for drywall. Regular 1/2 inch drywall has an expected fire rating of 10 - 12 minutes.
See:
There are various things happening to the regular drywall in a fire.
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As indicated in the article above(drywall is 50% water by volume), the water in the gypsum core helps provide the fire resistance. After the water evaporates, the material shrinks and dries and crumbles(Type X and Type C drywall have fiber glass or other reactive material embedded into the gypsum to resist the shrinkage). The flames(hot gases) enter the wall cavity and the studs catch fire.
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IMO, the paper covering is there to hold the gypsum together. Once the paper is burned away and weakened, the gypsum can have cracks, holes, etc when exposed to the fire or it will also crack when exposed to small changes/movement in the framing because the paper is not there anymore to hold the gypsum together. Then the cracks/holes etc in the gypsum allow the passage of flames(hot gas) into the wall cavity and the studs catch fire.
There are fully non-combustible drywall products such as the GP DensGlass. The paper covering on the gypsum is replaced with non-combustible fiberglass. DensGlass is also used as exterior wall sheathing as well.
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Basic 1/2" drywall is not used for fire blocking (although it does provide some)… 5/8" flame spread rated X drywall is what is used.
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Sorry, I’m not sure where you got the idea that 1/2 inch drywall cant be used. In the 2018 IRC for garage-dwelling fire separation, 5/8 inch type X is only used on the ceiling of a garage if there is habitable space above the garage. Otherwise 1/2 inch regular drywall is allowed. If the local AHJ wants to be more stringent and require 5/8 inch Type X everywhere then you do what he wants, but there is nothing in the model code that says you can’t.
Even directly under the section for fireblocking 1/2 inch drywall is allowed.
In commercial, regular 1/2 inch drywall is allowed as part of a fire rated assembly. You would look at 721 Prescriptive Fire Resistance or 722 Calculated Fire Resistance in the IBC for that. Of course there are various stipulations but yes it is actually allowed.
For example of a prescriptive interior partition wall with a 1-hour rating see:
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That’s correct so the 1/4" setback is permitted. Wood is a different story.
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I call it out every time I see it.
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I always call it out. Cleaning off oxidation and cleaning off overspray is two different things. Even the breakers with overspray on them are trash.
Now, let’s talk about combustible materials🤣
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Thanks for all the opinions guys! Thats exactly what I was expecting. But I wasnt expecting the turn in the convo… I stayed out of that one 
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Let him…
You report, client decides what is important.
P.S. I reported it every time.
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Coward!!!
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