Installing foam insulation pre-existing walls


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Old 04-26-19, 06:27 PM
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Installing foam insulation pre-existing walls

I have a cold home in the winter and have sprayed expanding foam around receptacles and switches. I’ve been researching injection foam and one side says mold can form because of moisture problems and that doesn’t sound good. Does anyone have any input regarding positive and negative findings of injection foam?
 
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Old 04-26-19, 07:22 PM
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Foam is best when there are no inside walls and it can simply be sprayed.

Why is it that your home is cold - are the walls not insulated? What is your location and source of heat?
 
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Old 04-27-19, 04:33 AM
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As SS is saying, you have to know what you have to determine what you will get. A basic energy audit (and you can do your own) would identify where the cold spots are and why.

In general, sealing air leakage (more than just the electrical boxes) is a high priority with good results. To provide more advice we need to know climate region and some details about your house.

I've never used injection foam but I would look at the rest of the wall assembly and where any moisture barriers are currently located. Is it open cell or closed cell?

Bud
 
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Old 05-01-19, 05:04 AM
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I’m in Oklahoma City, the home was built in 2003 and has fiberglass batts in the exterior walls. We have natural gas heating and to supplement the heat on cold days we use the gas fireplace which is unvented and the burner is supposed to be ventless.
 
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Old 05-01-19, 05:52 AM
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An 03 home should be reasonably well insulated and exterior walls full of that fiberglass. That means an injection foam would have to compress the fiberglass with mixed results and mixed improvement.

Do you have a basement, finished or unfinished. An unfinished basement gives you access for air sealing and perimeter insulation, good improvement and easy. Air sealing in the attic, especially any major leaks that were not closed off, recessed lights, drop ceilings, chimney path, and plumbing and electrical.

Bud
 
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Old 05-01-19, 05:55 AM
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Natural gas puts a lot of moisture into the air so your house is probably already pretty humid in the winter.
 
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Old 05-01-19, 04:57 PM
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Yes, I have those confounded can lights in 3 rooms of the home. They are not energy efficient with their leaks. But they do have ones that supposedly are efficient.
 
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Old 05-01-19, 07:07 PM
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If you can get to them easily from, building a box out of drywall and sealing it over them is fine, then bury the boxes in lots of insulation.
 
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Old 05-02-19, 04:44 AM
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I think I'm going to take your advice, I already took out the bulbs from the can lights that put out so much heat in the summer and put retrofit LED lights in all the can fixtures so there isnt a lot of heat buildup or fire hazard with the retrofit lights. I'm going to buy Styrofoam 4X8's and make boxes to fit over the can light fixtures in the attic. If I cover all the can fixtures in the attic I can get to it will be beneficial even if there are a few left uncovered that are near exterior walls.
I'm just going to cut the Styrofoam board and create a box as you indicated and glue it together with either Elmer's wood glue, Gorilla glue etc and tape after it dries then use "foam in the can" to set the box on for a seal, and foam around the electrical wires where they go into the box once it's set in place.
Thanks for all the positive and helpful comments, I really didn't want the expense and mess of foam injection in the walls.
 
 

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