Results 1 to 5 of 5

Thread: In conc. Slab

  1. #1
    Join Date
    Aug 2005
    Posts
    32
    Question, has anybody out there installed supply duct in conc. slab latley, in a home.
    It's been sometime sence we have installed duct under slab.we have a gen. contractor that wonts us to install them in that way. I told him its going to be expensive.
    its in the pacific N.W. where it rains a lot.
    my question is what is the insulation requirments for under slab duct.
    the last time we did one we used just spunstrand duct.
    and I know insulation req. have changed.
    I won't to be prepar before I go to the building dept.
    Thanks for any information.

  2. #2
    Join Date
    Feb 2004
    Location
    chicago suburbs
    Posts
    4,422
    i just did a house addition last month like this. no insulation...just pvc coated spiral. easy money....get your shovel ready.
    FILL OUT YOUR PROFILE!!

  3. #3
    Join Date
    Aug 2005
    Posts
    32
    PVC coated spiral pipe. OK I'll try that.
    Thanks a lot tinner!

  4. #4
    Join Date
    Feb 2003
    Location
    Huntsville,AL
    Posts
    4,125
    under the slab!
    needs egg sized gravel over geofabric to drain away the moisture.
    I would use pvc -- coated pipes are hard to have joints properly coated in the field.

    check my prior posts for a mfgr of thin wall plastic -- they started by making pipe for lab hoods --
    harvest rainwater,make SHADE,R75/50/30= roof/wall/floor, use HVAC mastic,caulk all wall seams!

  5. #5
    Join Date
    Feb 2004
    Location
    chicago suburbs
    Posts
    4,422
    the fittings and couplings are PVC coated as well. i used United Duct seal (oil based)to seal all of my connections. this is a whole section of ductwork and special fittings made exclusivley for underground. it's not cheap...10'of 12" spiral was about $75.00. 6" adjustable elbow was about $15.00. this stuff is heavy gauge metal. it will obviously get wet under ground that is where the coating comes in.

    they back-filled with regular pea-gravel. then compacted it down. 4" of concrete after that and you're done.
    FILL OUT YOUR PROFILE!!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image