Outdoor Rigid Use?

[davej1270]

Not sure if this should be in the plumbing forum or here, but here I am. We are making a bardominium apartment above our barn and are running out utilities. My issue is that the water feed from the house has to exit above ground because the part of the house where the source is is on a 2' concrete pad. My thought here was to make a chase going out of the house down 3 feet and then on to the bardominium. I have a plastic 35gallon drum to use as a well for the chase to access the line. My original thought was to wrap the exposed pipe coming out of the house and down the well with heat tape and wrap insulation around the that, I was wondering if it would be a more effective insulator to ditch the drum and make the well out of 2'' rigid foam, but still wrap the exposed line with heat tape. The well will have a lid on it to cover 100% of the exposed pipe either way I do it. I just thought maybe the rigid board would be easier to work with in case I needed to replace the heat tape. Looking forward to your advice.

I live in zone 7a (SWVA)

 

[slvr22_bd]

I think your second thought about using rigid foam board is much better. A plastic drum isn't a good insulator and it would be really tough to get a proper seal. Rigid foam board like XPS has a much higher R-value than a plastic drum. It's also way easier to work with, as you noted. You can build a chase around the pipe and seal the joints with foam sealant to create a continuous, airtight thermal barrier. That's key to preventing heat loss and keeping cold air out!

I'd suggest wrapping the pipe with heat tape first, then building the insulated chase around it. The rigid foam will significantly reduce how often the heat tape needs to run, saving you money. A well-sealed lid on top is also crucial!

 

[DannySays67]

I think your second thought about using rigid foam board is much better. A plastic drum isn't a good insulator and it would be really tough to get a proper seal. Rigid foam board like XPS has a much higher R-value than a plastic drum. It's also way easier to work with, as you noted. You can build a chase around the pipe and seal the joints with foam sealant to create a continuous, airtight thermal barrier. That's key to preventing heat loss and keeping cold air out!

I'd suggest wrapping the pipe with heat tape first, then building the insulated chase around it. The rigid foam will significantly reduce how often the heat tape needs to run, saving you money. A well-sealed lid on top is also crucial!

I'm planning to insulate a water pipe in my garage, so this sounds like a smart way to do it. Did you use 2-inch foam board or something thicker? And for the top cover, did you make it from foam too or use something stronger? Just wondering what lasts the longest.

 

[slvr22_bd]

The 2-inch foam board is a good choice for most applications, especially since you're using heat tape as a backup. The thicker you go, the better the insulation, but 2-inch XPS has an R-value of 10, which is plenty for a garage in zone 7a. For the top, you can make the lid out of a piece of the same foam board and then cover it with a small piece of treated plywood to give it some rigidity and protection from damage. That way you get the insulation of the foam with the durability of the wood. The plywood will last a lot longer than the foam alone and the foam is easy enough to replace if needed!

 

[furg0y]

What you're describing will work fine as long as you keep two things in mind: keep the pipe and tape accessible, and don't rely on insulation alone to stop a freeze. Heat tape is your real protection, insulation just slows the loss. A barrel works well because it gives you a clean access point if you ever need to swap tape or fix a leak, whereas foam buried around the line is a pain to dig out later @davej1270

 

[latoureiffel]

I’d just go with the rigid foam, way easier to work with than a drum. Keep the heat tape on the pipe, make a little box out of the foam, and put a lid on it. If you need to swap the tape later, it’s simple.