# Heat Tape?



## RJJ (Aug 10, 2010)

Would you allow heat tape for water lines above a ceiling in a new 5k 1 story building? All lines a proposed to be run out side the conditioned space. If so do you have an es report on an approved tape!

PS: the IPC 2009 index freezing, Installation ........605.8 must be a typo because it has to do with manufactured nipples!


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## Coug Dad (Aug 10, 2010)

fire or domestic water lines?


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## mtlogcabin (Aug 10, 2010)

I would say heat tape is not an outright approval however under alternate means and methods it may be possible but why would you want a mechanical sytem for freeze protection versus a passive system (insulation)

305.6 Freezing.

Water, soil and waste pipes shall not be installed outside of a building, in attics or crawl spaces, concealed in outside walls, or in any other place subjected to freezing temperature unless adequate provision is made to protect such pipes from freezing by insulation or heat or both. Exterior water supply system piping shall be installed not less than 6 inches (152 mm) below the frost line and not less than 12 inches (305 mm) below grade.


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## Mule (Aug 10, 2010)

They manufacture nipples????? Sorry...mind in guter.

As far as the question goes I wouldn't allow heat tape as a freezeproof method. Now this is firing from the hip without researching. I've got in a little trouble doing this before.....


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## RJJ (Aug 10, 2010)

Domestic water. Heat is general. I would assume it means heat source. This plug in tapes are fine for some old dog building, but I don't think I could approve it for new. This is an M  or B use. Sorry I posted it under residential.

MT: I did find that section. My take would be create a chase and provide a heat source to maintain protection.

Last email in was that the wet system for sprinklers will be located in the same unconditioned space.

My response was " Houston! I think we have a problem" "Please stop all work until further notice."


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## Uncle Bob (Aug 10, 2010)

Electric heat tape is not designed for permenant use.  I've removed old heat tape from water lines many times; and, they were all in poor condition; and ususally not working.

Here are two different city water utility departments suggestions, to prevent freezing of water lines;

http://www.cincinnati-oh.gov/water/pages/-3377-/ 

and,

http://www.okc.gov/water/service/forms/preventfreezingpipes.aspx 

Electric heat tape is not design for multiple years of use,

Uncle Bob


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## mtlogcabin (Aug 10, 2010)

Sprinklers can be dry, glycol or tented. Depending on your temps it may be possible to run the water lines on top of the bottom cord of the trusses then blow in enough insulation on top. Found 2 old house here that where done that way. Bottom cords where 6" Insulation was about 12" above the pipes.


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## RJJ (Aug 10, 2010)

Seems that NFPA has list heat tape to account for 300 home fires in 07. Couldn't find anything on Commercial.

MT: may have thrown a curve here. This is posted in residential but is a commercial use. The roof is constructed with bar joists.

I approved a wet system in fully condition space. This would call for a revised plan. I did not review or approve the building plans and to that I have been given yet another mess. The BO is now ask what should he do? My response is stop the job until they get it right.

The over riding issue is who would approve heat tape?


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## pwood (Aug 10, 2010)

i would not approve heat tape. if the power went out like it does during winter storms with freezing temperatures it would be ugly. failure to pay the power bill, same results. tenting is questionable in freezing climates . i've  seen wet systems freeze and burst where tenting was used.


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## globe trekker (Aug 10, 2010)

RJJ,

My 2 cents worth  - -  I would say that the BO has to make the final decision

whether or not to allow it.   From all of the responses on here so far, it

doesn't sound like a good long term, durable option,  or even one that is

questionable if and when the power goes out.

.


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## Dr. J (Aug 11, 2010)

From UB's links:



> Use insulating tape and wrap it over the entire length of exposed pipe. You can also use flexible molded pipe sleeves. Cover all valves, pipe fittings, etc. with insulating tape or fiberglass. We do not recommend electric heat tape for insulating water lines.


I never can understand why people think just insulating pipe will prevent freezing without a heat source inside the insulation.  All insulation does is retard the flow of heat, not eliminate it.  Piping installed on the warm side of building insulation has a heat source of course, but a water line simply wrapped with insulation does not.  An insulated pipe will still freeze, just more slowly than a non-insulated pipe.  What may make people think this does work is that *IF* the line is flowing, new water is constantly being added which makes up for the heat loss through the insulation.  Bare pipe looses enough heat to freeze even with flowing water.  However if there is no flow, an insulated pipe will freeze.  The smaller the pipe, the quicker it will freeze.  This may work acceptably for a well used line in an location where temperatures drop below freezing only part of the day.  But for a remote line where it can be consistently below freezing for several days in a row, the pipe will need a heat source.

I agree that heat trace is less than ideal, and it is a matter of *when* not *if* it fails. If there is any other possibility such as running piping on the warm side of building insulation or a heated chase, that is the only way to go.  This is similar to a sewage lift station - if there is anyway to gravity flow it should.

The only time I design with heat trace is for systems that are expected to be shut off in the winter, but where the fall/spring can still require water service and experience *occasional* freezing conditions.  Cooling tower make up is one example (although there are usually ways to avoid exterior piping there as well).  If heat trace is used, it must be insulated to keep the heat in.

Unfortunately, I am not sure that OP is a violation of 305.6.  Heat trace is a source of "heat".  This section makes no mention of reliability of that heat source.  If there is a way to run the pipe on the warm side of the insulation it should be (why is the insulation on the ceiling in the first place, rather than as rigid insulation above the deck as is common with bar joist buildings).  I would understand if you used the "because I said so" clause to make 'em do so.


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## peach (Aug 11, 2010)

I don't think cord/plugs are allowed in a ceiling NEC thing.


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## RJJ (Aug 12, 2010)

Peach: I have to agree on the NEC part. That was in the back of my mind. Dr.J I always enjoy your insight,however I don't agree that heat can be expanded to heat tape. This is a case with the original plan reviewer not knowing what he was loooking at on the plans he approved. Once I  saw the plan it was clear that the detail indicated had to do with a remote water meter set up which is not part of the construction any more. The piping has been run above the conditioned space. The details for meeting the energy code have not been followed. The contractor now needs to devise a plan for compliance.

I never take the position of because I said so. My decisions 99% of the time are based on good planning and the code. When the code is gray or silent I look for the best solution that creates a win for all parties. The remaining 1% of decisions that fall in to the realm of because I said so are used for the Knuckle Heads that exist. As a BO and you as an Engineer, as well, have to deal with these types of clients.


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## Yankee (Aug 12, 2010)

I agree w/RJJ. Heat tape is not a design solution.


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## Dr. J (Aug 12, 2010)

First of all, it sounds like the OP situation is just plain wrong, and I agree it is poor design to rely only on heat trace for piping known to be frequently subject to freezing condtions.  However, the code issue is still rather wierd.  "_...protect such pipes from freezing by insulation or heat or both_".    Since is ok to just insulate the pipe (which does not really protect pipe from freezing), an insulated and heat traced pipe is still code compliant if you just pretend the heat trace does not exist for the purposes of freeze protection (even though that is the only thing really protecting it from freezing).


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## GHRoberts (Aug 12, 2010)

While it might be a poor idea, heat tape is approved. I really like the heat tape you cut to length and splice at boxes. I don't use. I just like it.


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## RJJ (Aug 12, 2010)

And George Just what approval exists for heat tape / trace for above a ceiling? Please share!


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## Dr. J (Aug 12, 2010)

Why is the relative position of a celing to the heat trace an approval issue?  Ok, so hard wire rather than plug in, and don't expose it in a plenum, but other than that, what does a ceiling have to do with it?


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## JBI (Aug 12, 2010)

The manufacturers listing information will tell you what uses and limitations apply. ICC-ES reports are not the end-all of 'approved'. The heat tape must be listed if it is to be used (most likely by UL), that listing describes where, when and under what conditions of use the product is intended for.


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## Yankee (Aug 12, 2010)

Dr. J said:
			
		

> Since is ok to just insulate the pipe (which does not really protect pipe from freezing), .


That would protect a pipe that has a constant stream of heated water


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