Wanted to add this, very informative. Credit goes to g.Potter on ic
Many growers consider fire a major threat in their grow room and certainlly there is a risk with the temperatures emitted by MH/HPS lights, trasformers, extension cords, etc. I am a builder who builds 200-300 homes per year. I am a master electrician and master carpenter. In the building business there are a number of measures taken to avoid fire in a home and then to contain a fire should one break out. The information and methods regarding fireblocking in new homes can be helpful to the indoor grower as he also wants to prevent fire altogether, but control it if it does occur. Hopefully this info will help someone do that. I'm also sure that others have found measures that help them feel more secure so add anything you wish. These suggestions will be helpful but they are not all encompassing.
I divide this topic into 2 categories:
Preventing fire: This is where you need to put the majority of your efforts. First, any time you carry an object into your grow room you need to consider whether it will burn or not, and if it will, how quickly? Make a U-turn with flash burn items, they just shouldn't be in there. Paper. towels and rags. oil based paints, (use latex), Mylar, aerosol cans, flammable liquids, rope, thin flammable board like luan, and anything else that might be in your room that will burn easily should go. Keep them outside of the room.
The next step is to protect your electrical system. This is an area where growers need help.
1. Your grow room MUST be on an arc fault breaker. No exceptions. If you have a grow room and its not on an arc fault breaker your rolling the dice and this applies to experience growers or beginners. No good alternatives here, and no second opinions. No arc fault and you can burn. The arc fault breaker dissallows a short either in the in=wall wiring or in an appliance such as a ballast.
You can buy arc fault breakers at Lowes or any electrical supply. The cost about 40 bucks and install right into your panel box. They come with instructions and if your careful its easy to install.
2. Your grow room should be ground faulted. The cheapest way to achieve this is to buy a ground fault receptacle from Lowes or anywhere. About 15 bucks and easy to install. Once again, read the instructions. Ground fault recepticals will keep you from being electricuted as well as preventing the sytem from grounding to something that will burn with the current. If you have many lights, get the ground fault breaker that goes in your panel box and protects the entire circuit.
3. Load resistence breakers. If you try to pull more electric than a circuit can handle, and this can happen without you actively doing anything, it will slowly heat up and the more you do it the hotter the line becomes.
The cheapest way to avoid this is to go to Lowes and buy a "pig tail" with an over load breaker in it. This breaker will kick if you try to pull too much through it. They are designed to keep a tool from burning up such as a saw by running an extension cord too far. They cost about $20.
Finally, I installed a 20 minute fire rated door, (metal) entering my room.
The second category of protection is that of firestopping. This involves containing the fire to your grow room should one break out. You surely don't want to loose your home because of a mishap with the grow room and yes it has happened more than once.
Your should be able to prevent an open flame from spreading beyond your growroom for up to 20 minutes and the materials that constitute your room should all posses a 20 minute fire rating, What posseses this rating.
Drywall. Drywall can withstand an open flame against it for more than 20 minutes without detiorating.
Osb/ Playwood. This has a 20 minute rating as long as its 3/4 thick. 7/16 will have about 15 minute rating.
Your growroom should be constructed from or at least have the walls and cieling covered with one of these 2 materials. Luan or very thin plywood, cardboard, paneling are virtual kindling and should be avoided.
If your room is made of something flammable, you might consider going to the nearest lumber company and buy some valley tin or flashing. This is thin metal that comes in rolls 2' wide and 20-50' long. Attach it to whatever surface you are trying to protect and it will deter a fire for 20 minutes.
Finally, consider firestopping in this manner. Flame travels up. Home builders discoverd several years ago that many homes burned because fire that started at a receptacle inside the wall cavity traveled up, found an exit through the hole in the top plate where the electrical wire came through and then would set the second floor of the home on fire. Simply stopping up that hole in the top plate contained the fire to the wall cavity.
If you can look up in your growroom and see a hole as big around as a #2 pencil, whatever is above that hole is succeptable to catching on fire should something happen in your room. Go to lowes or your local hardware store and buy some "fire caulk" and fiil that hole. Its $10 per tube. Use it to fill any gap or hole in your room.
Finall, fire needs air. I suggest using louvered vent covers on exhaust vents and intakes so that if the electric kicks, the vents close and eliminate the avenue to air for the fire.
DON'T USE FANS WHEN YOUR NOT THERE!!! A fan blowing on a spark is a fire. Use your fans when you are at home and try to avoid them when your'e not.
DON'T USE A HEAT REGULATED THERMOSTAT FOR EXHAUST!!! God I've seen people buy a heat regulated thermo so that when the room reaches a certain temperature a fan kicks on and clears the heat out. BAD BAD BAD!! If a fire breaks out, the temps rise and your thermostat will kick on and sucks air for the fire and pulls it through the ventilation system. Learn how long it takes to for your room to heat up and put it on a timer, not a heat sensitve thermostat.
Finally, evertime you shut the door on your room, make it a habit to take one last look with the question: Is there anything that can catch on fire while I'm gone?
Well, I'm sure there are other things you can do and feel free to add on to this thread. Be safe
G. row Pot ter
