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Reflective insulating rolls for basement? Any advice?

Post in 'DIY and General non-hearth advice' started by fishingpol, Jan 4, 2013.

  1. fishingpol

    fishingpol Minister of Fire

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    I have a portion of my basement that I use for woodworking sectioned off with a plastic wall and zip door. The location of my benches is in a corner with new basement windows on each wall a few feet from the corner. I have a fieldstone/mortared foundation with early concrete block on top of it. The height of the block varies from 3 course to about 6 courses as the foundation is built into a hill. The fieldstone is stepped and drops down with the elevation.

    I heat the area with a small ceramic electric heater with a fan. It can heat the area running steady, but barely. I was in a discussion with a coworker today and I came up with the idea of hanging a few rolls of insulating reflective material like "Reflectix". It is a bubble wrap type of material with aluminized layer on one or both sides. I am looking to keep heat in the work area and minimize drafts from the stone/block wall. Has anyone used the product and liked the results? I thought of rigid foam panels or fiberglass batts, but I don't want to build a framed wall out. The fieldstone wall is wider than the block wall so there is irregularities to the "plane" of the wall. I figure if the insulative sheet is out a few inches from the wall, there would be less work and less material. Just a matter of hanging the product and taping it at the seams. The rim joists are insulated with fiberglass batts between the floor joistsThis cold snap made it a little bit too cool to work down there especially when the stove is running upstairs. A cold work area is not very motivational. Any thoughts or ideas? This is by no means a finished basement, it's all business down there. I also like that I can roll the sheets up to inspect for a water leak if need be.


    http://www.reflectixinc.com/basepage.asp?PageName=Single Reflective Insulation&PageIndex=755

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  2. jharkin

    jharkin Minister of Fire

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    I put reflectix panels behind my iron steam radiators. In that application they work very well, reflecting the radiant heat into the room and keep the wall behind the radiator noticeably cooler. Their r value against conductive heat loss is minimal (maybe R2 ?) however so I don't know how much it would help in your case.
  3. fishingpol

    fishingpol Minister of Fire

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    Good to know Jeremy. They do have a low r value. They recommend having an air space behind it to help the insulative value. If the sheets were put up directly on the wall, they would have little to no value to them. I did find a different manufacturer that has the reflective film on both sides and I can purchase it direct. I like that they are mold resistant as they will be near the basement wall.

    http://www.radiantguard.com/reflective-single-bubble-reflective-insulation-500sf.aspx
  4. peakbagger

    peakbagger Minister of Fire

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    As a radiant barrier and an infiltration barrier it should work although I am somewhat concerned with a stone foundation, that water may come in through the walls and possibly cause a mold situation due to lack of ventilation. If properly installed you can get some additional R value by an sir space at the back, but the width of the gap has to be tightly controlled to less than an inch, otherwise convective flow starts in the air gap and effectively draws heat from the warm surface and transfers it to the cold surface.
  5. fishingpol

    fishingpol Minister of Fire

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    Hmm, the air space would have to be several inches out from the block but closer to the stone foundation. This location of the basement is pretty dry except for a really heavy downpour that a clogged gutter would overflow putting water right next to the foundation. I guess I look at the single layer of plastic keeps a bit of heat in the workspace, so if a bubble layer with reflective metalized skin should do a better job even if hung a few inches out. I was going to leave a small air gap at the bottom to get some air circulation. It is just block, mortar and stone on the wall, so not much in the way organics for mold to feed off of.

    I am not really an expert at this, but more of try and see what works type. I do appreciate the information from those with more knowledge of this type of thing.
  6. semipro

    semipro Minister of Fire

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    You may want to read this article to see what can really be done with a field stone foundation if you're so inclined.
    I realize this is probably much more than you want to to do but you should know all your options.
    http://www.buildingscience.com/documents/insights/bsi-041-rubble-foundations

    I think you're real problems are losses due to conduction and convection. In theory you could decrease convective losses with good installation of the radiant material but there are better ways to do that.

    A radiant barrier may help some but may not be worth the effort.
  7. fishingpol

    fishingpol Minister of Fire

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    Wow, lots in that article. I don't have a real moisture issue. No musty smell at all in the basement, solid framing. I even have a few solid cedar posts sitting on the conrete floor to support 2 carrying beams down there. Years ago I improved the drainage on the uphill side of the house. I improved the hillside where water would run down from the neighbors yard and directed it away from the house. The downspouts are directed away from the foundation and move most of the water away. The basement is pretty dry except when a gutter overflows and may cause a wet corner. That would be shame on me for a lack of monitoring the gutter clogs. For the few short weeks of cold weather, I think the barrier would be the best way, least expensive and easiest to move to inspect if needed. The workspace was at 50::F unheated on the coldest day this week at 4::Foutside.

    Edit: I do remember a few years ago, that there was a product that was injected into the ground right next to fieldstone foundations. I believe it was a polyurethane injection grout that would fill any voids and strengthen walls. Moisture helped cure the polyurethane, much like gorilla glue from what I recalled. I believe it was waterproof once cured.

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