Under slab insulation?

[TeachDerf]

We're now building a 28x28 attached to house. We have 20"x 9" footer, 48" height concrete block foundation to top of slab and 16" block fndnt. on top of that. We've been given 1,000 ft of plex tubing and a manifold for radiant in-floor; BUT 2" rigid insulation will cost $1,000. We don't plan on heating the garage, (however the option would be there for kids that inherit the place someday). Plan to pour footer late next week. Anyone know of more economical alternative?

 

[Randy in Maine]

2" Insulation is about $1/square foot. Do it.

You only need about 784 linear feet of 1/2" O2 barrier pex tubing. I would do about 4 loops 200' long.

You only get one chance here to do it right.

 

[jockeyjohn]

Pink stuff at HD is 32 a sheet here. $1 a sq ft. The blue stuff at the L store is 41 a sheet. I was able to get it from a different manufacturer in Denver for 28 a sheet in a full bunk of 46 I believe. I saved a bit...and then will head off to the HD to get the 10 pieces other pieces I will need.

As mentioned above...DO IT!!

 

[Chris705]

Try to find used on Craig's list?

 

[Crazy68Dart]

Try to find used on Craig's list?

It is worth a look. I lucked out just this past week. Found some 2" 40 psi foamular on craigslist. Enough to do stem walls before backfill and entire floor under slab. 40 psi is overkill but i could not pass up om the savings.

 

[kaferfahrer]

I have posted the following alternative a couple of times, have a search.

Find your nearest garage door or insulated man-door manufacturer. They will be selling or giving away scraps of their products or pieces left over from manufacture (when the manufacture a man-door with a window in it, they make the whole door then cut the hole out for the window).

These scraps are recognized to be a superior product over rigid foam insulation. Studies have shown that the insulate-ive factor (R-value) is greater per unit volume, they have a tougher surface for wheeling wheelbarrows or walking on, and they are more often than no far cheaper (mine were half the price of rigid foam, delivered)

Ask around at your local non-big-box lumber yards and you will find them. They are out there