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plumber red 01-30-2010 09:57 AM

freezing pipes / bad insulation
i recently bought a house that had what i thought was a nicely reno'd updstairs bath.

today the temperature dipped to -13C and the water stopped running out of my sink.

i had felt coldness around the floor AND on the ceiling below around the patio door below so i went outside and removed some of the fascia and soffit to see what i could see.

here is what i found - the insulation is a joke. the patio door was never really insulated, and the pipes can easily be seen from the outside (*once i removed some wood and insulation)

this is the view from the back, the bathroom is the dormer above

the view gets closer and closer

HELP!!! i don't know what to do. I used a heater and got the water flowing again to the sink -- how do i prevent it from freezing again?

if i spray foam the pipes will this stop the freezing?


daveb1 01-30-2010 10:14 AM

Do you know if the bathroom dormer is an addition ir original construction?I'm thinking addition because of the ice dams in the eaves trough except where the dormer is.

plumber red 01-30-2010 10:17 AM

it's origional, every house in the neighbourhood has them - post WW2 construction, 1954 i think.

i think the entire soffit needs to be pulled and sprayfoamed? not sure what to do here

---i'm guessing no ice dams because no snow lands there due to the dormer

Scuba_Dave 01-30-2010 10:51 AM

I would have that area sprayed
Ideally you want the pipes open to the inside wall
IE no insulation between the pipes & the inside wall
That allows the heat from the inside to keep the pipes warmer
Those pipes should have been up higher near the floor

Depending upon the distance between the lower soffit & the pipes you could use R30 (10") or R38 insulation (12") to insulate the area
You need insulation between the lower soffit area - that you tore out - & also against the roof sheathing
Ideally you want a small rafter vent in there to allow moisture to evaporate
But you may not have room for that, & with that small a roof section maybe not needed
You only want to insulate without a rafter vent under that dormer

That vent on the right side of the dormer does not look correct either by todays code

AllanJ 01-30-2010 10:53 AM

There must be insulation between the pipe and the outside wall but not between the pipe and heated/semiheated interior space. Leave a V shaped channel empty, as wide at the inside wall as it is deep to expose the pipe.

You will need to reach in and remove some of the insulation between the first story ceiling and the second story floor so the pipe is "exposed" to the ceiling below.

You may also need to cut open the bathroom wall (from the inside) to adjust the insulation there.

plumber red 01-30-2010 11:12 AM


so the issue also seems to be shoddy insulatio nthe entire length of the area above the patio door - which was a remodel done in the last 10 years.

can i use a can of great stuff expaning foam around the pipes? its drafty there. i figured if i could put some hardboard insulation between the pipes and the outside, then sprayfoam the snot out of everything all along the span above the door, also getting the foam in all the cracks around the top of the patio door to seal things off. do i not need some sort of vapour barrier between the soffit and the insulation above it? the wood they ha was cheap 1/4" pressboard, should i install plywood?\

thanks for the help, BTW

daveb1 01-30-2010 12:13 PM

Spray foaming your pipes will prevent the warm air away from the pipes so with nithing to keep them warm they will just freeze again and then your heater won't be able to thaw them either.As Allen said you need to reach in and pull the insulation out from between the pipes and the inside of the house and put it between the pipes and the outside.Vapour barrier goes between the warm side of the house and the insulation.

plumber red 01-30-2010 02:54 PM

here is what i did

removed insulation above copper pipes, and removed all the rammed in pink and old stuff (clearly recycled) found out the dormer is open to itself, but not to the rest of the house.

using an isomeric sealant, put a thick vapour barrier on essentially sealing off the holes leading to the floor of the bathroom across the entire span of the dormer

installed R32 batt insulation in the holes left over

-----here is where i am currently at-----------

plan to put plywood over insulation (bottom of soffit)

plan to reinstall soffit


oh'mike 01-30-2010 03:34 PM

That sounds pretty good as long as you keep the cold drafts from reaching the pipes.

Just something to keep in mind for the future.
Copper stretches when it gets frozen--Next time it freezes it may burst.

If you end up having to re-pipe that section in the future think seriously about PEX tubing--It has the best tolerance to freezing of all the commonly available piping systems.(no soldering -easy to fish into existing spaces)--MIKE--

plumber red 01-30-2010 04:40 PM

should i have wrapped the pipes in insulating foam as well?

concretemasonry 01-30-2010 05:46 PM

Just turn the taps open for a small trickle of water. I lived in northern Michigan and because of the water table and geology, the main supply was subject to freezing. Fortunately, it was known and just like a snow emergency, there was a notificiation when to do that to do and there was a percentage deduction on the water bill. I kept track of the water usage and it made little difference in the total usage. Since you have a unique situation, there will be no credit, the cost is not as much as people think for a short term situation.

I would stuff in the fiberglass junk between the pipes and the exterior walls and wherever it makes sense and then cover to prevent the wind from getting in. This wall allow you to look at it when it is better and make a better decision on the repairs or corrections and do them when the weather is better and you can do them right.

Just toss the temporary fiberglass since it may have moisture in it and will be relatively worthless. The insulate properly and consider foam. It is not really necessary to insulate between the hot and cold line, since the exterior cold draws out the heat. there is nothing wrong with foam wraps on the supply since it does decrease the condensation on some lines. Just make sure you are not insulating between the pipes, that were installed in the wrong places, since the interior keeps them warm enough avoid isolating them from the interior that is a controlled environment.


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