Polyiso with algae on it – OK?
I came across a bunch of 4’x4′ 2″ polyiso for a very cheap price. Roofing company had it sitting outside in Memphis wet/humid area. I brought it home and plan to use it for shop, home, and solar lumber kiln.
I am thinking to let it sit on my trailer since it has a bit of the algae on it already. Build a small overhead shed for my sawmill and air drying location and set it under that cover. Wait for a good dry spell; and then fill a kiddy pool with with water and a bag of pool shocker. Immerse the foam in it for a few seconds, set it on a drain return sheet metal and then let the sun dry it out. Restack it under the sawmill shed and use it on it’s respective projects.
Am I on the right/wrong track? Thank you. -Mike
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Replies
Weigh a couple of samples. If it's substantially more than 2lbs per cubic foot you may need to stack it somewhere with 2x4 spacers between sheets for a few months to let it dry out. Stacked sheet on sheet left on the trailer it would take forever to dry out.
You can leave the algae on it (as long as it stays dry it won't grow) or just spray the edges with an algaecide- no need to try to submerge it.
Don’t immerse the polyiso in water! Polyiso will wick water, so immersion will just increase the moisture content which is the opposite of what you want to do. Heat and air movement will help dry things. Your idea of letting the sheets air dry is a good one. Make sure the air is moving too, use a fan if necassary.
You can kill the algae with a bleach solution. That’s basically the same as the pool shock (chlorine, mostly). Just mist some on the algae infested areas. You’ll still have discoloration though. It may be best to just cut off the worst edges to get to clean material.
Bill
Thank you. That makes good sense. I sticker between boards when air drying lumber. I will do the same here. When rain is inbound, I will throw a tarp over the foam, until I get that shed built next week. Once built, I will sticker it for drying under the shed roof.