planning to plumb & insulate the ditches...

You should get some replies from people who have taken this approach. I'm considering essentially the same thing if I can't get someone to do the foam for me. One thing you should do is check the specs on the foam sleeves to make sure make sure what you buy can tolerate the heat. I've read of a few cases where the foam broke down quickly at temps less than 180. Seems many people prefer a wrap insulation.

It took me a bit of "Googling" before I found a polyurethane insulation installer. Now, having been down that road, I can suggest an easier way to find one. Look under commercial roof installers - many flat or moderatly sloped roofs are now done in 2 or 3 inches of polyurethane, which is supposed to work well for ditch/trench insulation. It is closed cell, waterproof and weatherproof - has to be for the long warranties they give for roof insulation. It also molds around whatever it is sprayed onto. I also learned that they are using that product to seal stud walls, including electrical wiring, in flood prone areas like New Orleans, so you may well be able to find installers in your part of the world, too. It is a bit spendy, however, so given your circumstances, I don't know if you find it worth the cost.

Theres always the DIY foam kits that anyone can use.
Will

Yah, but I looked into those DIY kits..... They were more expensive then to have the Corbond guy come and do it for me... Plus, I'm somewhat less than sold on the insulating value of the DIY stuff vs a name brand like Corbond, etc.......

I have Corbond in my house and garage, so I know it works. The diy kits would be good for people without any installers in their areas. Not certain on how they stack up to pro applied stuff.
Will

I did just that,OX barrier pex and corragated non slotted pipe I fed them through 6" instead of 4" for later in ground options and a section of mule tape for future pulls of stuff..I live in New York and I done this with no insulation..BAD IDEA!! I was loosing almost 20 degrees just to get to the house 100' away,lets not talk about return temps as they were way too low to be safe for the unit..The pipe was 4' down and I almost never had snow accumulate over it for long,I should have run it with the sidewalk for a deicer LOL... I would NEVER do it again INSULATE any way you can..Any is better than none..Good luck..
DAVE

I predict... there will be a lot of cussing going on as you try to feed 90 feet of insulated tubes into a corrugated drain pipe Buy a bucket of talcum powder.
And you end up with a fairly low R-value depending on the wall thickness.

The foam board with tubes attached and spray foamed in the trench intrigues me. I'm anxious to get some data from folks that have tried it. Recording the delta t from one end to the other for a period of time would tell a lot. Maybe shop for a used data logger on e-bay to record for the winter.

hr

I liked the sound of Eforest's setup that he described in another thread, spray foam around SDR pipe. This would give an insulated conduit that you could put your piping through. I guess it would be similar to the insul-seal product, but the joints would be covered with continuous foam. From Eforest's post, its probably less expensive also.

Anyone else doing anything similar?

Rob