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Thread: White paint or mylar on brick concrete?

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    White paint or mylar on brick concrete?

    I was planning on painting the walls in my growroom white and not use any mylar, but the room is in the basement and 2 of the walls are concrete brick, will just painting the room be enough or should i put up mylar all around?

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    420 Member POTential's Avatar
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    Re: white paint or mylar on brick concrete??

    I would definitely mylar, after using a a white concrete sealant on all exposed concrete. Concrete is very porous and easily infiltrated by mold and fungus. It is also uneven in most cases meaning even it painted white it will still scatter the light. Since it is the basement is it possible the concrete was previously sealed?

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    Re: white paint or mylar on brick concrete??

    no, this is a fairly old room that has recently been cleaned out and will be painted tommorrow. im going to plan on getting mylar, any recomendations on where to get cheap mylar. ALSO i have a space 4.2 W ft by 5.7 L feet = 23.6 sq. ft. Ive read that you should have 20 watts per sq ft, and that would be like 460 watts or around 7000 lumens, i think. does anyone have a good idea for what type of flourescent lighting would be best. the long tubes or just the simple screw in bulbs like in boss's grow. any advice would be great!!

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    Re: white paint or mylar on brick concrete??

    I've read up to 50watt per square foot. Consider heat/ventilation from the bulbs and your space limitations. You should try to have reflectors for your lights/lighting setup as well.

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    Re: white paint or mylar on brick concrete??

    I have 20 seeds and I don't expect all of them to get to full maturity, So im wondering if I should maybe try and build a wall or something or make some sort of cutain to reduce the space the light has to spread out, because i would need too many lights for a full 23 sq ft room.

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    Re: white paint or mylar on brick concrete??

    Definately build the wall to shorten the size of the room. 20 watts per sf is the minimum light you want. 50watts per sf is optimum. White paint beat out mylar for reflectibilty in tests that were done by a major grow shop and if mold could be a problem adding a barrier over the brick that would allow moisture to collect and be trapped (like mylar) might be worse. If your stuck on using a reflective item like mylar you might like the stuff I use. It's a product we call astrofoil. I buy it at home depot or lowes or orchard supply hardware(OSH) for about $2.00 a square foot. It comes in 4 foot wide rolls and I bought 18 feet of this roll for a total of $36.00 the last time I needed some. Unlike mylar, astrofoil can be wiped down and used for years and it's thick and is almost impossible to tear on accident.
    Last edited by Racefan; 05-06-2008 at 06:18 PM.

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    Re: white paint or mylar on brick concrete??

    yeah, im going to build a hanging wall to make the room 8-10 sf and that way i can up my wattage per sf. I don't necessarily need to have mylar, but i am concerned that i wont get the right type of reflectivity off of the concrete walls due to the inconsistency in flatness. What IF i were to staple mylar to some cardboard and have those cardboard pieces surround the room, not on the walls but near the walls. Do you think that would prevent my possible mold problem?

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    Re: white paint or mylar on brick concrete??

    Might work.

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    Re: white paint or mylar on brick concrete??

    It doesn't really matter what you use as long as you apply liberal amounts of sealant to the concrete first. It may be useful to have it be removable, like your mylar on cardboard idea. This way it can be easily cleaned and you can keep a watchful eyes on the concrete walls as well. Mylar does tear easily as Raceful advised so I would investigate the astrofoil as well.

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    Re: white paint or mylar on brick concrete??

    Mylar typically comes in 1mm and 2mm thicknesses, the former only being useful for covering a completely flat wall. The 1mm stuff tears easily but the 2mm is pretty strong.
    Si Vis Pacem, Para Bellum- "If You Seek Peace, Prepare For War."

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    420 Member HandyMF4u's Avatar
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    Re: white paint or mylar on brick concrete??

    I kind of like the 1/4 inch thick reflective insulation foam that is used behind vinyl siding.
    It can be hung from string and moved aside very easily.
    "Make the most of the Indian Hemp Seed and sow it everywhere.”
    ~George Washington

    Handy was here.