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.
i just did a house addition last month like this. no insulation...just pvc coated spiral. easy money....get your shovel ready.
PVC coated spiral pipe. OK I'll try that.
Thanks a lot tinner!
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 --
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.