Nonconductive plastic ties for concrete block

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Does anyone know of nonconductive plastic (nonconductive for heat) ties that can be installed by the mason in concrete block walls? If they exist, these ties could be used to attach rigid insulation on the outside of the home after the block laying, yet would not contribute to thermal bridging. Thanks, Brad

-- BF morris (chelone@cci-29palms.com), December 08, 2001

Answers

you want eh insulation on the outside?,, why not use wood?

-- stan (sopal@net-port.com), December 08, 2001.

Not sure what you mean Stan; do you mean use wood for ties or use wood for insulation or use wood for anchoring the insulation? Thanks, Brad

-- BF morris (chelone@cci-29palms.com), December 08, 2001.

why do you want insulation on the outside?? you can alwaya use 1x2,lagged in to nail the insulation to

-- stan (sopal@net-port.com), December 08, 2001.

The outside of a block home is the most logical place to install insulation. One would want to be surrounded by the thermal mass of the concrete and make that work as an aid in storing cool or heat *directly into the interior* depending on the time of the year. Thanks, Brad

-- BF Morris (chelone@cci-29palms.com), December 08, 2001.

Brad, this is just an idea, but if you embed plastic anchors that are designed to use with sheetrock into the mortar you could screw into them with metal screws and still break the thermal bridge to some extent. Another idea is to use regular TapCon style concrete screws and partially bury them in the rigid insulation and caulk the holes...

I have never thought of the concept of a thermal bridge before, thanks for the mental challenge!

-- gilly (wayoutfarm@skybest.com), December 08, 2001.



Brad, why not use the same ties as are used in ICF construction? Insulated Concrete Forms are styrofoam blocks interlocked into 'forms' and held together/apart by plastic strap/ties. There are many different styles and manufacturers in the marketplace. Each has a slightly different take on how to do it and, hence, on strap/tie styles.

If you're not already familiar with the concept, in ICF construction the straps/ties also hold your rebar in place and the walls are poured concrete between the two foam 'forms.' A conventional basement wall thickness done this way with the foam 'forms' left in place has a nominal R-value in excess of R-50. Any reason you want to use block rather than a poured wall? It seems to me as though an ICF wall system might be just what you're looking for without all the work and uncertainties of reinventing the wheel, so to speak. I hope this helps.

-- Gary in Indiana (gk6854@aol.com), December 09, 2001.


I've thought about those foam forms, and they've got a lot going for them, particularly as far as getting strong weatherproof load-bearing walls up FAST goes. Just play Lego with hollow (top and bottom) foam- plastic boxes (and reinforcing), then pour concrete into them. Of course the problem is that you end up with foam-surfaced walls inside as well as outside. Then you either have to live with it - and I think the foam would mark up something horrible; or you have to put another wall surface on top of it.

BF, could you simply use adhesive? Something like the brand we have here called "Liquid Nails" - if not to attach your insulation, then to attach the ties to the surface of the blocks.

-- Don Armstrong (from Australia) (darmst@yahoo.com.au), December 09, 2001.


<<>>

Gary, I live in the lower Mojave desert; down here cooling is the main thing we need to keep in mind for the house we want to build. We want an extremely well insulated, all concrete home with the insulation on the outside of the concrete only. This will allows us to harness the mass of the concrete to our benefit. A properly designed home of this type will allow us to do most of our cooling at night when equipment runs most efficiently and "coast" through much of the daytime when high temperatures cause refridgeration units to work harder.

Yes, we are familiar with ICF's but due to the insulation characteristics of these and the lesser amount of concrete we would have to act as thermal mass, we decided to look elsewhere. A home of thick, cast in place concrete walls sheathed on the outside with four inches of rigid sheeting would be spiffy. Simply plaster the interior side of the concrete walls. Thanks, Brad

-- BF Morris (chelone@cci-29palms.com), December 09, 2001.


you dont say where you are at,, outside insulation has been used,, but only works well in milder climates. HArd sun,, or hard winters break down the styrofoam,, UV break down,, and brittleness in extreme cold. Ive installed ALOT of vinyl siding with the rigid foam,, they are many things that dammge that stuff in the extreme cold, WOuld couls embedd most any platic in the mortar and tie to that

-- stan (sopal@net-port.com), December 09, 2001.

Hmm, this one has had me thinking for a while. I also live in a cinderblock house- cinder blocks, I believe, are much more efficient than solid concrete- if that what you were refering to in using forms. At any rate, I also have plans to install insulation on the outside of the house soon, so this is what I am planning on doing... incidentally- I used liquid nails on the interior walls to put up panneling. IF the wall remains dry all the time (mine does) it works wonders- I have had no problems with any bows or popouts. On the outside, this I my plan. I will first drill a bunch (one every 16 inches or so) of holes and install drywall (or concrete) type plastic anchors- the blue things that you run a screw down into. I will then add a layer or 1/4 inch or 1/2 inch foam insulation- the foam wall board type, taking a nail and locating each anchor hole. I will then take cut log outers from the local sawmill- having each one cut into 6 8 or 10 inch widths and screw these to the anchors, using a layer of carefully applied liquid nails/ great stuff spray insulation or some type of chinking looking rubberized insulation in strips between the log outers. I have always wanted a log cabin, gosh durn it, not a cinderblock house, so have one I will (well, almost=) I will then (the logs are debarked) apply a layer of clear or light polyurethane sealer over that to protect the wood (although the house will, by then have a porch all the way across the front and sides) oh yeah- at the ends, I will simply install an upright 2 by 6, 8 or 10, so the corner looks right- it wont look like the logs are interlocking, though. The anchors will act as a thermal bride to a certain extent, however, adding the foam insulation will by far make up for that. The house, in just cinderblock form, does an excellent job of insulation- takes 12 or so hours to trully heat it up or cool it down.

-- Kevin in NC (Vantravlrs@aol.com), December 09, 2001.


I think this is an interesting subject. Kevin, why do you think blocks are more efficient than solid concrete? I've wondered myself if the greater amount of air trapped in blocks would cause this? Stands to reason that the more dense a substance is, the higher the rate of conductivity.

Query- Would you consider using insulation thicker than the half inch you mention? Why not use two inch thick rigid insulation. (assuming cost is not the issue) Thanks very much for your comments! Brad

-- BF Morris (chelone@cci-29palms.com), December 10, 2001.


Here's a thought, don't know how much in exterior wall dimensions you can lose but this works great. I built my reburn fireplace like this in northern Nevada. Do a double cinder block wall, cinder block is not as dense as concrete so it won't conduct much heat, use two six inch blocks or a four and a six or the combination you need for wall thickness and bearing requirements. Rebar and solid grout both walls with the 2" foam board in between up to the eave line.

-- raymond l gray (rorlgray@graytv.com), December 10, 2001.

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