Replies

1. 
   davidmason | May 27, 2001 08:05pm | #1

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   I don't think you're going to gain anything with just the 2" ins.

   Why don't you just run the tubing for the infloor heat and hook it up at a later date, when you can afford it. My 2 cents , Dave.

1. 
   Ian.D.Gilham. | May 27, 2001 08:28pm | #2

   *James,Not only will the 2" thick insulation be insufficient, you're asking it to support the concrete floor.I would use 4" insulation and place it so that there is a 4" gap around the perimeter and a couple of 4" gaps across the floor. Place two 1/2" rebar 1" up from the bottom of each gap and pour a 4" slab, reinforced with mesh, over the whole thing. This will give you 8" drop beams which should be sufficient support.You don't give dimensions, so I can't be precise, but the drop-beams across the slab should be no more than 10' apart.This won't guarantee the basement will be warm, but it will cut down on heat-loss through the floor

1. 
   Gabe_Martel | May 27, 2001 10:21pm | #3

   *James,You don't indicate where you are located. In a cold climate region, the addition of 2" of High density styrofoam will certainly have a positive effect. Don't worry about the styrofoam's ability to support your concrete, it's designed for that.As stated in the first post, intall the tubing and prepare for the future when you can afford to finish the project.But in the alternative, the insulation alone will be fine.Gabe

1. 
   G.LaLonde | May 27, 2001 11:07pm | #4

   *James, Didn't you hear the news this weekend. The politicians are going to give you some of your tax money back! They want you to spend it on something. You would be very wise to spend it on 1/2" PEX tubing for your floor and then you can use your tax savings every year until you have the whole system hooked up. You only have one chance to do this and you should take the opportunity while you can to install the tubing! You can either use flat reinforcing mesh in the concrete and tie the tubing to it or you can staple it directly to the styrofoam.

1. 
   Chris_Koehn | May 28, 2001 12:34am | #5

   *2" of dow blue board is under my slab, which has pex tubing in it. The foam is indeed meant for this application. Although you do need to do a really good job leveling the stone below it'cause the weight of the concrete will crack the foam otherwise. There's 6 mil poly on top of my foam too. Some guys put it below the foam.Tie the PEX tubing to 6X6 wire re-mesh with zip ties. Your heating guy should be able to tell you how far abart to make the loops. Then be sure the masons pull the mesh up to the middle of the slab. Otherwise stand the mesh up on 1 1/2" chairs if the masons give you any slack. You have the opportunity to create zones easily with this type of heat. Make seperate loops back to one spot (where the manifold will be located), and when you do get around to hooking it up you can install lever valves and have a very simple, elegant way to keep different parts of the floor different temps. I picked up a 3' piece of unistrut and bolted it to the wall, and ran the zone loops into brackets that mounted in to the unistrut. A simple and effective way to control the tubing and keep the zones straight. Do it- you won't be sorry!

2. 
   Mike_Willms | May 28, 2001 02:26am | #6

   *A flat sand base under the foam works well too.

2. 
   James_Wright | May 28, 2001 02:26am | #7

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   I am building a house and want the basement to be warm. My plumber and Hvac guys suggest Infloor heating. But I cant afford it. Can't I just install 2 " foam insulation over the stone and pour my concrete on top. The insulation is supposed to be installed below the radiant tubing anyway. I would think that this would be better than nothing at all.Thank you for any input