Weather proof a box on a wall with flashing

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  #1  
Old 05-28-15, 06:32 AM
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Weather proof a box on a wall with flashing

I have built an outdoor sauna for a friend out of materials he collected from renovation projects over the years. The thermostat he had on hand was an interior unit and it has been mounted on the exterior back of the building.

I had in mind that I would build a box to fit over it and weather proof it. I first thought I would seal it with silicone (and probably still will in some places) but noticed he also has a bunch of aluminium flashing lying around. So, if you have a wooden wall, with a box lets say 8"x10"x5" fixed to it, what is common practice as far as flashing it goes?

I'll attach an image in case it helps. The whole thing is made out of 2x6 tongue and groove planks i.e. no weather siding if the solution involved that.
This is probably a very obvious question. As handy as I am I have never used flashing in my life! Thanks in advance
Josh

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  #2  
Old 05-28-15, 07:12 AM
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Is it line voltage switch or low voltage? What size is it? Will it fit in a standard single gang box? Can you post a picture of the switch?
 
  #3  
Old 05-28-15, 10:28 AM
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No chance it will fit in a single box. It's 240V in and out. Mechanical thermostat with a capillary tube. I didn't want to remove the plastic cause it's a pain to tape back up but you get the idea. 3/4" conduit so you get an idea of size. It's about 3" wide by 5" tall and 3" deep. Roughly.

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  #4  
Old 05-28-15, 11:21 AM
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Moved to Electrical forum because this is an electrical question with safety and code issues.
 
  #5  
Old 05-28-15, 05:53 PM
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First off your field bent 180 is WAY too tight. 3/4" conduit can not be bent tighter than 5" diameter. (a 5" circle should fit on the inside of the bend)

Can we see it without the plastic bag? (He asks fearing what he will see)
 
  #6  
Old 05-28-15, 07:38 PM
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Is bending conduit in any way breaking code? It was a 45 before I bent it, it didn't seem to strain it. It is going to be inside the box anyway, the bend was just another precaution. I've had an electrician and a builder take a look at it, neither mentioned anything about it.

I will take a photo of it tomorrow if it is necessary but I just want to weather proof everything from the bend down to below the plastic bag. The electrician has ok'd everything from the breaker board in the house to the heater inside. Just needs weather proofing.
 
  #7  
Old 05-29-15, 04:40 AM
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Why not come I to the bottom of the box with the PVC ? Why not use a PVC pull box mount to the Tstat control with appropriate fittings?no flashing needed.
Geo
 
  #8  
Old 05-29-15, 05:39 AM
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Is bending conduit in any way breaking code?
Yes, the 5" rule is out of the NEC. However now I notice you are in Canada and the CEC may not be the same.
 
  #9  
Old 05-29-15, 07:52 AM
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The thermostats port for supply is on top that's why I didn't come to the bottom. I could easily cut the bend out and have the conduit terminate at the bottom it's not a big deal right. I just thought, in torrential rain if the box somehow failed at least it is another block in the road for water entering the conduit. I can remove it. But the supply lead still needs to go to the top of the thermostat.

I looked around a couple of local hardware stores for a PVC box or an outdoor router box or something like that. Came up short which is why I'm here...

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  #10  
Old 05-29-15, 08:53 AM
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The questions why aren't you using one intended for outside use. Why isn't it inside if intended for interior use?
I just thought, in torrential rain if the box somehow failed at least it is another block in the road for water entering the conduit.
All conduit used outside is considered a wet location and must contain cable or wire rated for wet locations. What wire or cable did you use? What kind of cable is the black cable coming out of the bottom? Is the circuit GFCI protected?
 
  #11  
Old 05-29-15, 11:59 AM
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By 'interior' I mean it's for a sauna inside a house - the Tstat is indoors but not inside the sauna. No steel components will ever be inside a sauna as this will burn skin during operation if touched. I would prefer to keep this project cost-free if possible, as it has been up until now.

The cable from breaker to Tstat is PVC insulated 3/10+ground and is inside 3/4" PVC conduit. The black cablen from Tstat to heater is part of the heater kit. It is some kind of flexible sheath and has printed on it 'Liquid-Tight Conduit-Conseal'. It is crimped on both ends which fit into recesses and are torqued up by nuts.

Yes it is GFCI protected.
 
  #12  
Old 05-29-15, 12:50 PM
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But is it 10-3 NM-b (AKA Romex) or is it UF-b? Is there GFCI protection?

http://www.alibaba.com/product-detai...529807208.html

http://www.alibaba.com/pvc-waterproo...promotion.html
 

Last edited by ray2047; 05-29-15 at 01:12 PM.
  #13  
Old 05-29-15, 07:07 PM
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It is Romex simpull NMD90 10/3.

Yes, there is a GFCI between the breaker box and sauna, as I said.

Is this not possible to do to code with a weather proofed box? I will order online as a last resort, would prefer to use materials on hand.
 
  #14  
Old 05-29-15, 07:43 PM
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JoshNZ,

Why you don't simply build an extended roof (porch style) to that side of the Sauna providing protection with a roof for the Tstat current installation. Also if you want you can simply attach a wall at one side of two walls one at each side of the Tstat attached to the roof extension and that will provide even more rain water protection to your current Tstat installation.

Something like this example (please forgive me my horrible skills with Paint):

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You know about Carpentry, so you should get the idea.


Thanks a lot.


Jos
 
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  #15  
Old 05-29-15, 08:00 PM
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JoshNZ,

You don't have to build a full length extended roof. You just have to build a small porch style mini roof over the Tstat like these:

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Just replace the doors you see at the images with the image of your installed at the exterior Tstat... if those doors are rain protected by those roofs, then your Tstat current installation could be also protected from rain water applying the same principle of building those roofs above it... it's a simple, basic Carpentry and Physic idea that will work to keep the rain water away from the wall where your Tstat is installed.


Thanks a lot.


Jos
 
  #16  
Old 05-29-15, 08:54 PM
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It is Romex simpull NMD90 10/3.
You can not use NM-b for this purpose because it is for dry locations. Any conduit outside is expected to fill with water and therefore is a wet location.

Did you look at my links in #14. There are many more like that. One of those boxes would work okay.

I doubt Jos' suggestions would meet code. It would still be a wet location IMHO.

If you build a box flashing should be under the siding board. I'd cover the entire top of the box with flashing, bend it over the edges of the top and secure with #6x" pan head sheet metal screws* into the edge of the top board.

*Sheet metal screws because you need threads all the way to the screw head (wood screws stop two thirds of the way).
 

Last edited by ray2047; 05-29-15 at 10:22 PM.
  #17  
Old 05-29-15, 10:42 PM
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How about a steel or plastic NEMA 3R enclosure?
 
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Old 05-30-15, 06:07 AM
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Even with a roof over it I think it will still get wet. I like Justin's options the best.
 
  #19  
Old 05-30-15, 08:33 AM
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The roof would need to extend quite far out to remove the stat from the angle of the rain. The 3R enclosure or a weatherproof t-stat is the way to go.
 
  #20  
Old 05-30-15, 11:03 AM
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pcboss

The roof would need to extend quite far out to remove the stat from the angle of the rain.
Just to clarify something about the angle of the rain in this case...

However... If you see the first image of the Sauna that JoshNZ uploaded, you will notice two aspects that I considered to propose the roof. First, notice that the Tstat is installed at the rear back wall of the Sauna. Second, notice that beyond the rear back wall, that side of the Sauna are a few trees close to the wall... therefore, those trees will protect that side of the Sauna from rain in wide angle produced by windy rain, the trees will protect from windy rain, therefore a small porch style roof right over the Tsast will protect the Tstat, because of the trees the rain will fall almost straight down not with angle at that side of the Sauna.

Thanks.

Jos
 

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  #21  
Old 05-30-15, 11:38 AM
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I forgot to wrap it back in plastic last night and we had a down pour. Light bulb in my brain came on about an hour into the rain and I went out there with a bag. I got wetter walking out there than I did spending 5 minutes beside it wrapping it up. The Tstat barely had water spots on it so it is somewhat protected from the trees.

I'm sure a roof would work until that one day per year where you get horizontal rain from just the right direction. It needs to be sealed from all directions.

I will keep my eye out for an enclosure it would be the easiest solution but I can't find any in our LHS, it is on a cottage which doesn't really have a mailing address so ordering online isn't practical. But if it is necessary I will.

ray2047, is there somewhere I can find info on what canadian electrical code says about NM-b in sealed conduit, or can you reference where it says so? If it's really breaking code the Tstat is the least of my worries
 
  #22  
Old 05-30-15, 12:02 PM
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JoshNZ,

until that one day per year where you get horizontal rain
Are you expecting a Hurricane to happen in Canada??? ...

I'm living in the Caribbean I can tell you about horizontal with severe strong winds rain; but in Canada I will never expect that to happen... a severe snowstorm in the other hand...

Thanks.

Jos
 
  #23  
Old 05-30-15, 02:04 PM
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We get bad enough wind here to find trees laying across the road etc occasionally. I'd rather have it sealed and not need it to be, than need it to be and not have it sealed haha.
 
  #24  
Old 05-30-15, 02:08 PM
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Besides it is a code issue, I'm doing a favour for someone the last thing I want is to leave them high and dry with insurance if something with it or something else goes wrong. So I guess I should look at this NM-b issue first Would like to see a definite reference saying it's illegal to put in conduit in Canada before I rip it all out
 
  #25  
Old 05-30-15, 02:24 PM
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Look at the code article for NM to look for allowed usages as well as prohibited usages.
 
  #26  
Old 05-30-15, 03:06 PM
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It not illegal to install NM-b in conduit, it is illegal to use NM-b in a wet location. Conduit outside is a wet location.

See NEC 2011:
300.9 (says if conduit is in a wet location, the inside is considered a wet location)
310.10(C) (says what conductors are allowed in wet locations)
334.12(B)(4) (says NM is not allowed in damp or wet locations)
 
  #27  
Old 05-30-15, 03:11 PM
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The CEC probably has the same prohibitions.
 
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Old 05-30-15, 03:14 PM
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Hi pcboss and Tolyn Ironhand,

I'm aware that pcboss based his answers on the National Electrical Code and that Tolyn posted Code references of the NEC...

BUT... with all respect, I ask you: Are you aware that JoshNZ is asking for references of the Code IN CANADA, NOT NATIONAL (US) CODE, BUT FROM CANADA???

I see that your replies too repetitive, without providing accurate information or references regarding the Canadian Electrical Code yet.

With all respect your last replies are inaccurate as they are based in NEC, when clearly JoshNZ have to follow specific regulations made by the CSA of Canada. Complying with the NEC can still result on an improper installation at Canada, etc. so any references about NEC are invalid for his case.
 
  #29  
Old 05-30-15, 03:20 PM
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I hate to say it, but you're better off to gut and redo the whole thing.

- Table 19 of the CEC does not list NMD90 for use in a raceway. You could run NMD90 to the back of a PVC box mounted on the side of the house, but will need individual conductors (RW90 would be your best bet) from the box to the thermostat. You will need to duct seal around the loomex connector when mounting the box also.
- Your PVC raceway is not complete. It looks like the PVC stops short of the box and you have the cable in an L16. Your PVC need to be in a PVC connector attached to the box, and if coming in to the top you will need a sealing ring. The way you have it now is definitely going to let water in.
(side note: josi, we do get sideways rain once and awhile when the wind picks up, but upside down sideways blow every direction snow is indeed the main thing to watch out for as we see it 6 months of the year in some places.)
- Too much bend in your PVC. Tolyn is correct, you need a 5" radius for your bends. Basically for your 90 - 90, you would see a 10" gap between pipes. You would be better off coming in from below a box. You are also only allowed four 90's, or 360 degrees worth of bend in every run from box to box.
- Your timer needs to be in a weatherproof box. One like Justin posted would suffice.
- PVC needs to be strapped within 750mm of your box and every 750mm from there on.
- The black cable is likely TECK90, which needs to be strapped within 300mm of your box and every 1.5m from there on. These are code minimum requirements, you could strap closer together for appearance sake if you like.
- Saunas require a timer for the heater. They must be mounted outside of the sauna and cannot have a setting for more than 1 hour. This is a safety thing so you don't fall asleep and cook yourself.
 
  #30  
Old 05-30-15, 03:22 PM
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pcboss, you stated:

The CEC probably has the same prohibitions
.

That statement is even more innacurate.

You should never assumed that, without presenting the actual references to compare the NEC and CEC by CSA code regulations. Otherwise, assuming that things may be similar, the same etc. can still result in a Code Violation regardless if the referenced procedure is safe, correct, under code in USA, it may still be a violation on a different country.

Thank you!

Jos
 
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Old 05-30-15, 04:03 PM
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BUT... with all respect, I ask you: Are you aware that JoshNZ is asking for references of the Code IN CANADA, NOT NATIONAL (US) CODE, BUT FROM CANADA???
Yes. Did you read my post #8? I mentioned it there. CEC and NEC are quite similar which is why we have continued this discussion and all my references are as listed from the NEC.

Thank you MR. Awesome for your response. Great info!
 
  #32  
Old 05-30-15, 04:17 PM
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Mr. Awesome thanks for the detailed reply.

Can I pull the NMD90, lose the sheath, and run the conductors and ground through the conduit by themselves?

By duct seal you mean the putty like stuff?

I know the PVC raceway is not complete, that thermostat is not where the conduit will terminate it will terminate in the box that goes around it, whatever that ends up being. And I will do away with the bend. Feel like I've been accused for stabbing a child for putting that in there lol...

I know a timer is needed, still working on that. The thermostat goes higher than 90C which is also a violation today too I think.

Is there anything that mentions how long a run can be? It is ~70ft of cable and has more than 360 worth of turns so I didn't finish the conduit and pull it, I did it in sections and glued a joint being careful not to get any on the cable inside. I know this isn't recommended but there was no way around it.
 
  #33  
Old 05-30-15, 04:34 PM
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I'll just poke my head in for a moment and jump out to let you guys have your fun. No you can't strip the sheath off NM and use the individual conductors. The conductors inside the sheath are not rated as THHN/THWN, which is what you need if running individual conductors. Curious as to why you had so many bends in it? I have done it in sections, but it is a real pita compared to making your conduit run, and fishing through with a pull string.
 
  #34  
Old 05-30-15, 04:39 PM
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Sorry Josh but you will need separate conductors for the conduit. Everything about nmd90 was designed for use indoors and above ground. Because you will be running underground where the conduit will likely take on water and freeze, you need something with thicker insulation on it.

Yes duct seal is the putty stuff.

Your bend poses no danger. You got your cable through so it worked, but if you're shooting for a code compliant install then it does not work. Keep in mind the guys commenting on your bend likely work in the field and would get a good smack, or a pink slip, for doing a bend in such a way lol.

I can't comment on the temperature limitation. I would imagine that your sauna heater has a manufacturer spec for your thermostat temperature.

You run can be virtually as long as you need it to be. General rule of thumb though is every 100' you need to upsize your wire. for a 70' run you're still ok with your 10AWG wire (ive assumed a 30A circuit?) If you come in to the bottom of your timer box, and bottom of your wall mount box on the house, in theory you should only have the 2 90s. Offsets into the boxes also need to be factored in. Generally we use 30 degree bends so you're looking at 120 degrees just to get out of one box onto a wall and off the wall into another. If you do end up being over, it isn't the end of the world and poses no danger, but again it wouldn't be code compliant.
 
  #35  
Old 05-30-15, 04:51 PM
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I neglected to mention expansion joints for your pvc.
You can buy one: http://images.meproducts.net/PEJ-50.jpg

Or make one. You won't run your pvc straight to the boxes. Put a female (FA) threaded end on your pvc about 10" from your box, then a liquid tight flex connector and liquid tight flex from your pvc to the box. This will allow your pvc to expand and contract without tearing away from your boxes when the temperature ranges from -40 to 40.
 
  #36  
Old 05-30-15, 05:49 PM
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Ah ****ty. You guys have ruined my day lol. But thanks for doing so. Looks like it's not going to be a free-project after all I will speak to the owner and see what he wants to do.

Basically from the breaker panel, 8/3 cable ran to a GFCI under the house, then the 8/3 continued to a hot tub on the side of the house. The hot tub is long since gone so I pulled the cable back to where the GFCI is and ran it in a different direction under the house, stapling it to the joists (Question 1- how far apart are staples allowed to be?), then into a junction box. That is all before my time and none of my business the only thing I did was change the breaker from a 40A to a 30A to facilitate the cheaper 10/3 cable and lower power requirement.
So, from that junction box, provided I use less than 360 of turns, use RW90 or something rated for exposed (or concealed? Question 2...) wet locations under table 19, and finish the raceway at the box with an appropriate connector, and include an expansion joint or flexible section... I should be ok? Have I missed anything.

Can the box be made of wood? I know I'm beating a dead horse with this but I would still like it to be wooden. Goes with the look better than a dogs balls plastic or metal box.
 
  #37  
Old 05-30-15, 06:19 PM
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Can the box be made of wood?
See the last part of post #16. As to if it would meet code is up to the local inspector. You could inclose an appropriate box in wood.

Does it have lights inside? In the U.S. you could not run a separate 120 volt line for lights and it couldn't come off on the 240 without using a subpanel.
 
  #38  
Old 05-30-15, 06:31 PM
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It does have one lamp inside, between one hot conductor and neutral. It was my understanding that if the GFCI was standard and not a double pole - 240/120V, this setup would trip it as it would detect a difference in current on the two hot conductors. It is a 240/120V GFCI and does work, what would be the purpose of this if it were illegal?

The guy I'm doing this for is a builder himself, so I doubt he will have an inspector take a look. What is the issue exactly, if things are not to code but are safe anyway, i.e. you had 390 of bends between the two boxes?

I know with the way the conduit is lying, it could get 1-2ft longer on some phenomenally hot day, it would not stress anything at either end. Do I really need the expansion joint?
 
  #39  
Old 05-30-15, 08:42 PM
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The reason you can only have 360 degrees between pull points is because it is almost imposable to install the wire after the conduit is installed with that many bends. Also there is a risk of damaging the insulation.

It is a 240/120V GFCI and does work, what would be the purpose of this if it were illegal?
You may only have one feed to a building. (with some special exceptions) It sounds like that is what you have so this is a non issue.
 
  #40  
Old 05-30-15, 08:57 PM
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It does have one lamp inside, between one hot conductor and neutral.
In the U.S. The maximum breaker size would be 20 amps for a general purpose 120 circuit but you said it has a 30 amp breaker. Is the cable to the light #10?
The guy I'm doing this for is a builder himself, so I doubt he will have an inspector take a look.
Yes, I can understand why a hack like that wouldn't pull a permit. He wouldn't want an inspector red flagging his work. Any competent builder wants permits and inspections to protect them from law suits.
 

Last edited by ray2047; 05-30-15 at 09:12 PM.
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