Building drain support above grade

[mrd]

I have a 3in building drain running about 6in or so above grade in a tall crawlspace. The floor joists are 3-1/2 feet above the pipe. What's the best way to support the drain?

I was considering using concrete blocks every 4', but I'm wondering if there's a chance the ground may settle. Plumbers tape hanging down 4' seems flimsy. Maybe tack a 2x4 vertically from the joists, with a strap at the end to the pipe..?

[cacher_chick]

I would use a clevis hangar supported by threaded rod.

[hj]

Plumber's tape hanging from the joists may LOOK flimsy, but it will support more weight than that line will ever create.

[bsperr]

You can also cut a v-notch into some 1*4 pickets secured vertically from the joists and strap the waste pipe into those with some plumber's tape.