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Residing with foam will add $3k in electrical work. Help?

jay443 | Posted in Energy Efficiency and Durability on

My 1966 rambler, located in Minnesota, has the original Masonite siding. I was planning on residing with LP SmartSide and using 2” of foam board insulation. But the problem has become the electrical service. Since my service is dropped overhead, adding 2” in thickness requires moving the service pole (will need a new hole in the roof), meter, and service entry.  I called an electrician to ask for a quote, and he told me that I will also need to bring my breaker box up to code, which requires moving it away from a wall to get the 30” clearance required. I’m looking at roughly $3k in electrician costs to do that whole job. 


What kind of options do I have here?  Is it possible to create a “channel” for the service pole/meter –put foam board around it and side right up to the channel, while leaving the meter attached to a board attached to the sheating? Will that cause problems with my sheathing? Anything else I could do? 


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  1. Expert Member


    Each utility, or jurisdiction, has their own rules for mounting the service, and as your electrician says, they have usually been tightened since most houses were built.

    If it were me, I'd avoid opening a can of worms and would consider leaving the area around the mast and meter alone. The main obstacle would then be architectural - that is making the area you don't re-side look like it was an intentional act which adds interest, rather than something you didn't get to.

  2. Expert Member
    BILL WICHERS | | #2

    I think your electrician is trying to get you to upgrade your entire service, which would take about a day and $3k is about right. You just need to move your meter a little bit. Assuming you have SE cable between the meter box and your electrical panel, it shouldn’t be difficult to move BUT there might be local code issues involved that would require the additional work with the panel. Check with your local electrical inspector about what you need to do.

    The service “pole” is not in your roof, that is the service “mast” and should be 2” rigid steel conduit. You might be able to reuse the old one, but the parts (conduit, weatherhead, boot for the roof penetration) aren't very expensive. A new meter box will probably be free from your electric company.

    While I have seen recessed meters in siding and the like, I wouldn’t compromise your insulation and wall assembly that way. See if your inspector is ok with just relocating the meter — make sure he knows it’s only a few inches for a reside — before you try anything else.


  3. jay443 | | #3

    Thanks for the replies. I see challenges for both. If I were to just leave everything as-is, I worry about the "look" and performance of that part of the wall, considering that it's a ~10 foot run of mast along the wall.

    On the other hand, to move the mast and meter out seems like a task that's too much for me. We're talking about having the service disconnected, drilling through the roof, running a new mast, installing a new meter, and having an inspection done all in the same day in order to restore power at night for my family.

  4. Expert Member
    Dana Dorsett | | #4

    As Bill said, the mast is steel conduit. I don't believe it's a code violation for foam insulation to touch the mast, or to insulate out & around the outside of the mast. There would need to be some sort of weatherproofing collar where the mast penetrated the roof or wall, but the rest should be fine. If the mast is 3" o.d. and your foam is 2" you might build out the foam to 4" on either side of it to bring it partially inside the thermal boundary and for the cosmetic issues of the siding, making it a slight bump-out rather than a recessed channel.

  5. jchatt2682 | | #5

    Thanks, Dana,

    I've attached a picture of what I'm up against. I don't think there's any room between the mast and the sheathing for any foam + siding. At least, a thickness of foam that meets the requirement of R 7.5 for my zone. It seems that the best thing to do would be to create a valley that's made out of something like a cellular PVC board directly attached to the sheathing, and build up the foam around it. Or will there be an issue if there is this uninsulated valley next to the foam?

    1. Expert Member
      Dana Dorsett | | #8

      I was suggesting boxing out around he exterior of the mast with foam on the outside of the mast with foam. Filling with fiber insulation around it is preferable than an open channel. With 1" of polyiso exterior to the mass and in-fill of cellulose or rockwool or fiberglass behind & around the sides mast you'd meet/beat the R7.5 necessary for dew point control. The thermal conductivity of the mast would make a somewhat cold line for the first portion below the roof line but if insulated right up to the roof deck (or an inch below) that won't be a wintertime moisture accumulation issue for the section of sheathing behind the mast.

      An inset around the meter box making either the foam or siding roughly co-planar with the front face of the box wouldn't be a visual disaster.

      I suspect a full height 2x4 an inch or two on either side of the meter box all the way to the soffit would give you enough room to work with at approximately the right depth.

      1. jay443 | | #9

        Hi Dana,

        Thanks. I see what you're saying now--treat the mast similar to how you would treat a HVAC duct in a basement remodel--box around it, and you won't even see it after finishing. I like that approach too. The only downside I would see is if I need electrical in the future that would require access to the mast. But, it hasn't been opened in the 50+ years that the house has been built, so it's unlikely that I'll need access in the future. I don't see myself upgrading to 200A service, so that would be the only thing.

        1. Expert Member
          BILL WICHERS | | #12

          The standard 2” mast will accommodate a 200 amp service. You might need a different meter box is all, your electric company would be able to tell you. Regarding foam touching the mast, code pretty much treats rigid steel conduit (the beefiest kind of conduit the code defines) as impervious to nearly anything so you shouldn’t have a problem there.

          The meter boxes aren’t waterproof, they are only rain tight. They are designed to be able to drain any accumulated moisture out the bottom of the box. If you box it in as Dana described, be sure to leave a little clearance under the bottom of the box and detail it into your wall stack up like you would for the bottom of a window to drain to the outside face of your WRB.


  6. jchatt2682 | | #6

    Pics here.

  7. jay443 | | #7

    Sorry. GBA is having issues with pictures right now....

    1. Expert Member
      BILL WICHERS | | #14

      Snip off those zip ties before your first inspection. You’re not supposed to strap other things to conduit runs. Inspectors love to fail things for that.

      The little ground strap your phone or cable TV service is grounded to needs to remain accessible per code. There is a different style of clamp available that clips to the bottom of the box though if that would work better for your situation.


  8. walta100 | | #10

    I am not an expert on the code. I do not recall any requirement for clearance to the sides of the panel. If your panel does not have the required clearance in front of the panel, I think you should make whatever changes are necessary to be code compliant. 30 inches of front clearance seems minable and sensible.

    It sounds like you need a new service entrance mast with an offset bend. The electrician that bid your job does not own the tool to make the bend so he wants to make a new hole in the roof.

    In my opinion several brands of panels are so dangerous they should be replaced ASAP. How old is your panel, what brand?

    It never hurts to have a few bids. Also consider now may be a good time move the service underground.


    1. Expert Member
      BILL WICHERS | | #13

      Code clearance for 120/240 volt services (less than 150 volts to ground) is 36” and is known as “dead front clearance”. The code means 36” must be clear in front of the panel from the floor to the ceiling for the full width of the panel.

      For the original poster: my quick read of the code says there is no 30” horizontal work space requirement for dead front switchboards which includes residential electrical panels. You just need the width of the panel itself clear, no extra space is needed on the sides. It is possible that you have a more stringent local code, I’m just going by what the national code book says.


  9. Expert Member
    MALCOLM TAYLOR | | #11

    Again - your code may differ, but the ones I'm familiar with don't allow the mast to be covered. That's why it's on the exterior of your wall, not in the wall cavity. I'd check with your electrician before boxing it in.

  10. jay443 | | #15

    Thanks everyone for your replies. I talked to my inspector this morning, and he stated that the electrical mast cannot be covered.

    With that in mind, I'm back to:
    -installing an entirely new mast, ~4'' away from where it is now
    -creating a channel of foam/siding around the mast and trying to make it look like I meant to do it

    Is it possible for a mast to have a bend in it? In other words, could I use the same roof penetration and just have the conduit bent away from the wall as it comes down?

    1. Expert Member
      Dana Dorsett | | #16

      It's fine to use long-radius ells in the mast conduit.

    2. Expert Member
      BILL WICHERS | | #19

      Yes, you can have bends in the mast, but you can’t have couplings in the section that supports the service drop. What you’re talking about is known as an “offset”. As others have mentioned, it takes a special hydraulic bender to bend the 2” rigid conduit and usually it’s just the industrial electrical contractors that will have this machine. Note that a conduit bender and a pipe or tube bender are not the same, the conduit bender will make a larger radius bend and won’t deform the conduit while doing it.

      Would it be possible for you to lift the boot from the roof, cut a notch with a jigsaw, and then slide the mast assembly further out from the wall? If you only need 4 more inches maybe that’s an option. You need to provide support under the eve and above the meter box. Exact locations will probably be dictated by your power company, but usually the under the eve needs to be close to the underside of the eve and above the meter box within 3 feet. The idea is to make the mast sufficiently strong to be able to support the service drop.


  11. Expert Member
    MALCOLM TAYLOR | | #17

    It may be, but there are probably requirements for how long it must be straight, and how many anchors it needs, before it penetrates the soffit and roof.

  12. walta100 | | #18

    Yes the new mast could be bent with the proper tool. But it is an expensive tool few residential electricians would use very often. So patching the roof may be less expensive than finding someone with this tool. Someone with this tool is more likely to be looking for big commercial work.

    Do you currently have 36” of clear space in front of your panel?

    My 67 rambler looked more like this.


  13. gusfhb | | #20

    I think what the electrician is saying is that once he touches the mast/meter/breaker box he has to be up to code, so he is probably not wrong about having to replace them.
    So moving the existing box out several inches is probably a non starter.

    I don't know why rigid conduit cannot be in the wall, it is in the wall, ground, all sorts of places, but if the inspector says so, it is probably not worth the argument. A quick search shows they make flush meter boxes for just this purpose.

    What is the cost of the energy lost in the next 20 years of having a 8 inch wide strip with no foam?

    I'm thinking less than 3 grand

    Not ideal, but if it saves the project...

    1. Expert Member
      MALCOLM TAYLOR | | #21

      I'd bet the heat loss over what is an extremely small area of the exterior walls is almost un-measurable.

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