No heat tapes inside walls. Ever.

Glad I posted this. So now my option is to insulate the pipes.

Is there any reason to ever seal in a shut off valve behind drywall?

Easier option, rip out that crap fiberglass around the pipes since you have it opened up and spray foam it with low expanding foam.

Normally you wouldnt have a problem since the pipes are on the warm side of the insulation but I am guessing you dont do laundry often enough to keep water moving in the pipes to stop them from freezing.

And yes, heat tape in general is a fire hazard. There are not many applications where it is safe to use it. They are only allowed on metal pipes and only if they do not touch anything else and only if they are accessible.

Never a good reason to seal in a shut off valve. They make spring loaded access panels if you dont want an opening in the wall. HD has 14x14 or 8x8 access panels.

http://www.homedepot.com/p/Unbranded-14-in-x-14-in-Spring-Loaded-Plastic-Access-Panel-APS14/204509831

Questions come to mind after reading your post. Why pipe didn't burst on one of the occasions of freezing. Are pipes UNDER attic insulation (they should be)? Assuming lines aren't freezing until going into wall,I you might make remedaition without opening wall all the way to ceiling. How about cutting out drywall from stud to stud ( about 14" wide) and about 24" high then covering with a cabinet door hinged to a face frame? You should be able to slide foam pipe insulation up to top plate and down to laundry box. The door would look better than a simple access panel plus could be left open allowing room air to circulate around pipes when cold weather is expected. As far as heat tape,2 feet of the 5 is all that is nessary because A heat rise's and copper conduct's heat very well. I'm not so sure it would pass code inspection but if door was open any time tape was on I wouldn't consider it as risky as tape in crawl space or other out of the way place. At least it would be easy to inspect.

I'm thinking the pipes didn't burst because the water lines to the washer gave room for the ice expansion?

Vith: there is no insulation - fiberglass or otherwise - around the pipes. The pipes are between the wall insulation and the drywall. At least that's the situation below the washer box. I am going to cut an exploratory hole on the wall above the washer box to see if they insulated the straight runs down the wall. I doubt it, but . . .

Klem, I like the cabinet door idea. But now I'm thinking simply insulating the pipes might be enough, and then seal up the drywall again. I think was over-thinking this project when I started. I just need to fix the builder's mistakes.

Since it's the laundry, I would use 2x2's to build a vertical 'chase' (tray) on the laundry room wall, and move the pipes to the inside wall. Then you could cover the chase with sheetrock.

Do NOT insulate the pipes. Cold is the absence of heat. Heat is created by the molecules moving faster (friction). If you insulate the pipes, the heat won't get to them and they will be even colder. Air molecules can't move around a pipe wrapped in foam, and where else is the heat supposed to come from? The water isn't moving either unless you are doing laundry 24/7.

What you need to do is insulate the wall cavity BEHIND the pipe with an insulation with more R-Value and less air movement (foam) and leave more air space all the way around the pipe for more air circulation around the pipe from the warm side of the wall. I would also put in a cheap grill as an access panel to the shutoff valve. If that doesn't prove to be enough, then add another flat grill at the top of the wall for better air circulation.

Ahhhh! This reminds me of the gardening adage: only ask gardening advice from one person, because no two people will give you the same answer. Status: I opened up the area above the washer box and found that the copper pipes are partly inside the insulation and partly outside the insulation as the pipe comes down. I covered them with foam pipe insulation and have the drywall screwed back in but I haven't mudded it in yet.

I am going to put a large access door below the washer box and try to add some insulation there. I found this study that just further confuses me:

Is Pipe Insulation Effective?

Multiple people recommended better insulation behind the pipes. This allows the heated space to keep the pipes warm and keeps the cold from outside affecting them. As I recommended, the low expanding spray foam will take care of any air penetrations which the fiberglass does nothing about and also leaves the pipes exposed to the interior heat. Spray foam in general is superior to fiberglass.

I am not sure what part is confusing about the study. It shows a few things.

(1) insulation around the pipe will only keep the hot water above room temperature for about an hour. After that, the cold from the outside will still freeze it overnight.

(2) insulation around the pipe does nothing for the cold water line.

(3) insulation around the pipe is only meant to keep hot water hot when it is being used more frequently than once per hour.

(4) air that is at the temperature you want the pipes to stay at is what you want surrounding the pipes because that ambient temperature is what the pipes will settle back to sooner than later every single time.

I get a couple calls every winter to fix frozen pipes that someone has tried to keep warm by stuffing insulation around them, and my phone number is unlisted. This is not like YOU keeping warm by covering up with a blanket. You have a very efficient calorie burning furnace INSIDE of you and therefore inside the blanket. The pipe and water do not make their own heat, and therefore also need to be INSIDE the blanket WITH THE HEATER to keep warm. NOT inside its own blanket with no heater. Think of it this way, if you go hunting and kill a polar bear in freezing weather, the bear will soon freeze hard as a rock because the furnace inside all its warm insulation is no longer working. Insulation only keeps things warmer than the surrounding temperatures for a little while (about an hour or two). Something else has to keep the molecules moving faster in order to keep it warm enough to not freeze overnight. By no shear coincidence, the reason a body shivers when cold.

Vith, I was trying for a bit of humor when I wrote that. I appreciate all the responses.

"I'm thinking the pipes didn't burst because the water lines to the washer gave room for the ice expansion?"

As ice freezes, it gets harder and expands more as it gets colder. The ice just hasn't gotten cold enough.

The pipes are not freezing in the ceiling because there is twice as much insulation above the pipe than in the wall. Also, heat rises, so there is a steady supply of heat loss from inside the house going to the pipes at the ceiling.

"This reminds me of the gardening adage: only ask gardening advice from one person, because no two people will give you the same answer."

I just read through everything again, and nobody told you to put insulation around the pipe except klem who was being contradictory with this; "plus could be left open allowing room air to circulate around pipes when cold weather is expected."

What?????

"You should be able to slide foam pipe insulation up to top plate and down to laundry box." AND "allowing room air to circulate around pipes when cold weather is expected." ALL AT THE SAME TIME????!!!! Is that the definition of an OXYMORON? (humor)

is the laundry room heated? open the drywall and cover the pipes with a louvered door so the pipes are exposed to inside air. Insulate behind the pipes. Essentially the ame as suggested above but without phsically moving the pipes in-board

Fred,I offered "OPTIONS". You are underestimating Greywings' ability to recconize that. If I gave required specs for center fire,muzzle loader and long bow to kill your proverbial bear,only an ox or moron would attempt useing all three at once. LOL

Sure, except that your "options" were more like choosing between an elephant gun and a snowball ;))

Where one is overkill and one would get you killed. I hope everyone is smart enough to figure out which is which, but after all, graywings did go ahead and put insulation around the pipes first, effectively throwing a snowball at it.

Disclaimer - snow is a great insulator, but it won't keep your pipes from freezing any more than any other cold insulation. (Igloos don't have water pipes)

Styrofoam coolers (insulation) are even designed to KEEP things frozen, not help thaw them out.

Actually, my current plan is along the lines of Klem's advice: I've insulated with foam wrap the pipes above the washer box. I've ordered an access panel for below the washer box, which, when open during cold weather, will allow the room heat to more easily reach the lower end of the pipes. The heat should slightly raise the temperature of the water within the pipes at their lowest point. The slightly higher water temperature should work its way up the pipes, and the foam covering the pipes should help retain the heat within the pipes at the top.

I foamed behind my washer supply lines, and they don't freeze. The trap is another story, since it has less insulation behind it, it has frozen twice in the last 7 winters. It is preventable by running a space heater, the laundry does not have a rad of it's own and has 2 exterior walls.

My laundry is this:

There is nit a tremendous opportunity for room heat to make its way back to the wall.

My pot-filler faucet is in an exterior wall, and it hasn't ever frozen even though it faces west (prevailing wind). It's covered with the normal black foam pipe-wraps.

May I ask what foam product you used?

In the end, where you live will make a difference. If it gets below 20°F, or down to 20° for more than an hour or two (dependind on wall thickness), you will be fighting a loosing battle with a pipe wrap. If it gets any colder, you would need to leave the faucet dripping for the pipe foam to do any good. But you can't leave it dripping with a washing machine. ALL the advice I see online that says to use foam wrap also includes leaving the water running in their solution. At that point, you probably wouldn't need the foam anyway. There is no "better" foam. They will all only keep the pipes warm for a limited time without the introduction of more heat (such as turning the oven on). In colder climates, all the foam does is insulate OUT the heat.

Hi, I used "Great Stuff" type generic foam. And only on the cold side, so room heat can reach it.

Casey