Running plumbing in the attic

Hi there - live in Toronto, Canada with some cold winters - not sure what the attic temp gets to exactly. I want to put in a rain shower head coming directly from above - but this would require running the copper up the wall and along the top of the shower in the attic (probably about 20" of copper in all in the attic). Question - would it be sufficent to insulate the pipe and perhaps build a box out of wall board to surround the pipe or should i stay away from this and just have a 90 degree pipe coming out of the wall. Obviously the wall option is safer but i've heard other contractors saying with insulation, a box and the attic insulation over the box it won't freeze - and even if it did - its not a "live" line....

Thoughts?

Thx
Ron

You are best to not insulate the pipe, but to cover the pipe with a blanket of insulation, trapping the warmth of the home with the pipe between the warm air and the insulation blanket. Attics can be very cold in Winter, and a leak in the attic drips down onto the living area. Granted it would only leak when you take showers, but it's still a leak.

If you slope it slightly, when the valve is off, the rainshower head will drain along with the line. If it is run close to the ceiling and has sufficient insulation above it, it will approximate the room temperature and with no water in the line, there's nothing to freeze. If there's an air leak, insulation like fiberglass acts like a good air filter, but is lousy for insulation, so ensure you've bocked any air leaks. The use of dense packed cellulose is good since it is less prone to air leaks.

Im in Ottawa (same climate), and looking to do something similar. But im only looking at running about a foot of copper pipe in the attic above the ceiling. I look at the responses (You guys are in washington etc) and worry that when our tempatures drop to -30C or -40C with the wind chill, it wont be enough. Laying a bat of insulation on the section, plus the blown might not be enough. Yes lets say you run a vertical section to the attic, then a sloped horizontal section.... yes it will drain, but that vertical section still has water in it. The other option could be to add a tub drain below that automatically drains the pipe (women love it when there is no tub and they can shave etc.), but im looking to leave this out for esthetics purposes. But if that is the last resort then.... oh and I dont want to use an electric pipe heater tape. Any ideas.... really want a rain shower head.

You can use something like this.

http://www.signaturehardware.com/product9463

John

A "wind chill" temperature is only applicable to the heat loss of the human body. Wind will speed up how quickly an inanimate object reaches ambient temperature, but it cannot decrease the temperature of the object below ambient.

jadziedzic said:

A "wind chill" temperature is only applicable to the heat loss of the human body. Wind will speed up how quickly an inanimate object reaches ambient temperature, but it cannot decrease the temperature of the object below ambient.

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That may be true but it drives the cold in. We do get more freeze ups on windy days. I'm sure you know about that.

John

Insulation does NOT prevent freezing, it just slows the process down. "heat" is the only thing that will prevent it. A rainfall shower head is a special situation, and there is a good chance that even sloping the pipe would NOT let the trapped water drain out. It may not be a "live" line, but the residual water COULD freeze and break, then when you turned the water on it WOULD be a live line and would leak.

Run it right along the top of the ceiling paneling and pile insulation on top of it. The heat from the room should keep it from freezing unless there's a lot of air infiltration. You want an insulation like blown-in cellulose rather than fiberglass, as it is denser and stops air movement better. If it has to run close to an outer wall, rethink, as then you may not be able to get enough insulation to trap the room heat that would keep it above freezing. Be prepared for a shot of (really) cold water when you first turn that head on! Some showerhead designs drain better than others. This can also be affected by the type of diverter used. Think finger over the end of a soda straw. If it drains, it can often take a very long time. Might be a good candidate for a 'toe-tester' (i.e., tub spout mounted low - also handy to fill a bucket) as that would leave the shower line end open and promote drainage.

I am a new member. I live in Maryland. I am dealing with numerous leaks from a addition the previous owner had done with the plumbing running through the attic. Thankfully no pipes ruptured but I do have loads of pin holes. Since 90% runs through the utility area I am re-piping by running it along the edge of the ceiling and the upper walls and then boxing it in. I have an 8 foot ceiling in my bathroom where I am putting in a another ceiling 8 inches lower to route the pipes over to the fixtures and toilet. If your ceiling is high enough you may consider that. I would not trust anything in the attic. I am curious if that is even code...

Good luck

I'm always confused what people think pipe insulation is going to do in an application like this.

Personally, if I did this, I would build an upside down V out of some rigid foam and use foam in a can to seal it. You can use 2" and then another layer of 2" on top of it.

You want the pipe to be surrounded by a pocket of WARM AIR from the bathroom, not encapsulated in insulation that will just keep the warm away from it.

Sidebar...there is no such thing as cold...cold is the absence of heat. You don't make cold, you remove heat. Heat always tries to spread out (i.e., heat colder areas). Insulation doesn't make heat, it just slows down the movement of the heat. Some types work better than others. Heat can move by either convective currents, conduction, or by radiation (and it's often a combination of them). The goal with your pipes is to put them close enough to a heat source (often the ceiling or an interior wall) with enough insulation towards the outside of them so that the temperature never gets below freezing.

It is critical to not lower the thermostat for long periods of time when you have pipes installed like that as that will limit the amount of heat that can migrate to them to keep them above freezing. Just like it's not a bad idea to open the kitchen cabinet doors by the sink on a really cold night when you setback the thermostat or go away on vacation and lower things...not enough heat may get to that location to keep the pipes above freezing.

Pex tubing is much less susceptable to damage if it freezes than most any other piping you may install, so that may be a consideration. It could damage a fitting, but often the tubing will absorb the expansion enough to prevent a fitting problem, but don't count on it - try to keep fittings out of freeze susceptable areas. Pex will return to normal size once the frozen plug thaws...on other types of piping, they are likely to split and when they thaw, create a really big, expensive mess.

I like to keep insulation above the pipes, to trap whatever heat is in the home.
No insulation should be between the warm side and the pipes.

New to the forum, concerned about piping ran in the attic. The previous owners have a space heater in the attic to keep pipes from freezing. I'm not comfortable with that. Wyoming has harsh winters. What measures could I take to assure pipes do not freeze? I have a plumber coming out today to inspect the plumbing & situation.

I prefer to keep all pipes below a blanket of insulation, and no insulation below. Also no insulation on the pipes. I like the warmth from the living area below being allowed to pass through the ceiling to warm the pipes, pipes that are covered on top and protected from the cold.

If your efforts to avoid freezing fail, at least you have PEX up there. The water will stop, but usually not break.

PEX A is promoted as best at not being damaged by freezing, but the other PEX pipes seem to endure nicely also.

A normal attic is vented, so electric space heaters should not be effective. If you block the vents and heat, bad things can happen. In particular, that would be very liable to cause an ice dam. Heck, even just the space heaters might cause an ice dam.

There is a way to turn an attic into conditioned space. In that, you insulate the underside of the roof with foam. You block vents. You get rid of the insulation over the ceiling. It is expensive. It has some significant advantages, however.

justagurl said:

New to the forum, concerned about piping ran in the attic. The previous owners have a space heater in the attic to keep pipes from freezing. I'm not comfortable with that. Wyoming has harsh winters. What measures could I take to assure pipes do not freeze? I have a plumber coming out today to inspect the plumbing & situation.

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In locations as cool in winter as WY both the plumbing and the ducts & air handler are much better off when installed fully inside the pressure and thermal boundary of the house. The parasitic losses of the HVAC equipment are almost always a double-digit percentage of the load (and energy use).

Terry's suggested remedy putting all plumbing on the warm-in-winter side of the attic insulation works, but even a small gap/air leak through the insulation on a windy sub-zero day can still freeze a pipe in a vented attic. It's better to use blown cellulose than batts or blown fiberglass, since cellulose is substantially more air retardent than fiberglass, and doesn't have edges that can be accidentally pulled back forming gaps.

Insulating at the roof deck, converting that attic to conditioned space is pretty expensive, but can be "worth it" depending on the particulars. Looking at the plank flooring in the attic I suspect this is house is pre- 1950, and may have little or no insulation between those attic floor joists. With simple roof lines putting rigid foam above the roof deck when it's time to re-roof can be less expensive than closed cell foam on the interior. With foam above the roof deck some amount of batt insulation on the underside of the roof deck can be added, but there is a minimum R-ratio that has to be met, which varies by local climate. The IRC prescribes at least 50% of R to be the roof deck in US climate zone 6 (which is most of Wyoming). With 3" of roofing polyiso (~R17) above the roof deck you could then install R15 high density batts (rock wool preferred- fiberglass would always be shedding airborne glass fiber particulates) snug to the under side. That would only be R32-ish at center cavity, but due to the R17 thermal break of the exterior foam over the rafters performance is comparable to R38 between joists. (Current IRC code-min is R49, but that can be CRAZY expensive to do at the roof deck.)

So, what are the insulation levels like at the attic floor? Is it even possible to snake the plumbing under it? Is there any vermiculite in there?