- 5 hours ago
Icicles hanging from your roof may be more than a sign of winter—they can point to heat escaping through your attic and an ice dam forming at the eaves. Elias Yoder explains how warm air melts snow from below, how trapped water can leak beneath shingles, and why recurring winter ceiling stains, damaged gutters, and wet insulation may share the same cause.
This practical home-maintenance guide covers safer ways to identify heat loss, seal attic air leaks, check insulation and ventilation, and understand when a temporary ice-dam measure may help. Learn how roof snow patterns reveal problem areas without climbing onto an icy roof. A useful guide to ice dams, roof icicles, attic insulation, winter roof leaks, home energy efficiency, and cold-weather house maintenance for homeowners troubleshooting seasonal damage.
This practical home-maintenance guide covers safer ways to identify heat loss, seal attic air leaks, check insulation and ventilation, and understand when a temporary ice-dam measure may help. Learn how roof snow patterns reveal problem areas without climbing onto an icy roof. A useful guide to ice dams, roof icicles, attic insulation, winter roof leaks, home energy efficiency, and cold-weather house maintenance for homeowners troubleshooting seasonal damage.
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LifestyleTranscript
00:00There is a row of icicles along the edge of your roof this morning, and you think it means it
00:05is
00:05cold out. It does not. It means your house is leaking. Every one of those was snow on your
00:12roof an hour ago, and something melted it, and it was not the sun, because it is 20 degrees out
00:18there. It was your house. That water ran down, reached the edge where there is no warm room
00:24underneath, froze again, and hung there where you can see it. So that pretty row along your gutter
00:31is a receipt. It is showing you, in a form you can count, the heat you paid for and did
00:37not keep.
00:39I am Elias Yoder, and almost everything people buy to deal with this is bought for the wrong part of
00:46the building. Behind those icicles there is usually a ridge of ice on the edge of the roof. That is
00:52the problem, and it has a name. An ice dam, and it works exactly as the word suggests.
00:59Your attic is warmer than it should be. It warms the underside of the roof, so snow melts from below,
01:06even on a freezing day. The water runs down under the snow until it reaches the last few feet of
01:13roof,
01:13the part that sticks out past the wall with nothing but outside air underneath. That part is cold. The
01:21water stops being water, and over a few days it builds into a ridge of solid ice. And now you
01:28have
01:28a dam, and behind a dam there is standing water. My grandmother read all of this off a roof from
01:36the
01:36road, and never once used the word attic. After a snow she would look at the houses as we went
01:42past and
01:43say, that one is heating the sky. The snow had gone patchy on it, or there were bare stripes melted
01:50through, and the house next door was still white all over. Icicles are not a sign of cold. They are
01:57a sign
01:58of heat. I gathered the whole of it into a book at EliasYoder.com. The book is the long version.
02:06If you want
02:07it, it is there. I will not mention it again. And here is why the standing water matters, which is
02:14the
02:14part that costs people real money. A shingle roof is built to shed water that is running downhill.
02:21That is the whole of what it does. Each one laps over the one below it, so water runs down
02:27over the top
02:28of them and off the edge. What it is not built to do is hold back water that is sitting
02:34still,
02:34and it certainly cannot hold back water that is being pushed uphill by the weight of more water
02:40behind it. So the water behind that dam works its way back up under the shingles, through the boards,
02:47and into your house. And it does not announce itself at the edge of the roof where the ice is.
02:53It turns up as a brown stain on a bedroom ceiling in February, or peeling paint at the top of
02:59a wall,
03:00or a wet patch in the corner that comes back every winter and dries out every spring and nobody ever
03:06gets to the bottom of. It soaks the insulation up there as well. And wet insulation does not insulate,
03:13which means more heat gets to the roof, which melts more snow, which makes a bigger dam.
03:19That is the part that catches people. Once it starts, it feeds itself.
03:24Two other things it does that people do not connect to it. A dam that builds up properly
03:30is a great weight of ice hanging off the very edge of a roof, and it will pull a gutter
03:36away from the
03:36fascia, or bend it out of shape. And every spring, people replace a gutter thinking the gutter failed.
03:43And the water that gets in sits against the top of the wall and the ends of the rafters,
03:48which is timber in the dark that nobody ever looks at. And it does there exactly what it does at
03:54the bottom of a wall.
03:55And here is how you know this is your problem, rather than a one-off leak. It comes back.
04:02Every winter, the same patch, the same corner, and in April it dries out, and the stain fades, and you
04:09forget.
04:10A leak that is seasonal and repeating, and always in the same place during thaw weather is this, nearly every
04:17time.
04:18Now, before I tell you what to do, I want to tell you what not to do,
04:22because this is a subject where nearly everything on sale is aimed at the ice.
04:28Do not get up on that roof. I want to say that once, plainly, and then not soften it.
04:34A snow-covered roof, over a layer of ice, in boots, in winter, is how people end up in hospital,
04:41or worse.
04:42And there is nothing up there worth it.
04:45Nothing in this video requires you to climb.
04:48Do not chip at the ice with a hammer, or an axe, or a spade.
04:52I understand the urge entirely.
04:55What you will do is break the shingles underneath it, which turns a winter problem into a roof repair.
05:01And you will be doing it standing on a ladder, footed in ice.
05:05Do not throw rock salt up there.
05:08It melts a little, and it corrodes gutters, and flashings, and fixings, and it kills whatever is planted underneath.
05:16And do not buy a new roof, hoping to cure this.
05:19And here I want to be exact, rather than dramatic, because there is a real distinction.
05:25A new roof will not stop a dam forming.
05:28The dam is made by heat from inside, and a cold overhang.
05:33And a new covering changes neither.
05:36What a properly built new roof does have, is a waterproof membrane across the bottom few feet.
05:43And that stops the water getting in when the dam forms.
05:47So if you are replacing a worn out roof anyway, insist on that membrane, and ask him to show you
05:54where it goes.
05:55Just do not tear off a sound roof, expecting the icicles to stop, because they will be back next winter,
06:02and you will have paid for the privilege.
06:04Right. The actual fix, and all of it, is inside the house.
06:091. Air leaks first, before insulation, before anything.
06:15This is the one people get in the wrong order, and it is the one that matters most.
06:21Warm air carries heat far faster than it seeps through insulation, so every hole between your ceiling and your attic
06:29is a chimney pouring heat up there.
06:311. The loft hatch, which on most houses is a thin board in a hole with no seal round it.
06:382. Recessed ceiling lights, especially the older, open ones, which are holes in your ceiling with a lamp in them.
06:463. The plastic housing of a bathroom or kitchen fan.
06:504. Everywhere a pipe or a cable goes up.
06:535. The gap at the top of interior walls.
06:566. The gap round a chimney.
06:587. Seal those, and you have cut most of the heat going up there, and you have not bought a
07:04single bag of anything yet.
07:068. What to seal them with? Roughly.
07:089. Small gaps round pipes and cables take ordinary expanding foam or a good sealant.
07:1510. Larger openings, like the top of a wall cavity or a space round ducting, take a piece of rigid
07:22board cut to fit and then sealed round the edges.
07:2511. The hatch takes weather strip round the frame and a piece of insulation fixed to the top of the
07:32board itself, which costs very little and is probably the single best hour you will spend up there.
07:3811. And one firm exception.
07:4112. Where a chimney or a metal flue pipe passes through, do not put foam or ordinary sealant against it.
07:4813. Those run hot, and they need non-combustible material and a proper clearance held round them, which means sheet
07:56metal and a high temperature sealant made for the job.
08:0014. If that is what you have, that is the one to ask somebody about rather than guess at.
08:0614. Then insulation, and the thing to check is not only how thick it is, but whether it goes all
08:13the way to the edges.
08:1415. The spot directly over the outside wall is the hardest place to get right and the most important, because
08:21that is the dividing line between the warm roof and the cold overhang.
08:2715. On depth, I will tell you to go and look up what is recommended where you actually live, rather
08:33than take a number from me, because it varies a great deal by climate, and the figures have gone up
08:39over the years.
08:3916. What I will say is that current guidance for cold parts of this country is a good deal more
08:46than most older houses have got, usually well over a foot of loose material, and that if you can stand
08:53in your loft and see the tops of the joists sticking up out of the insulation, you are a long
08:59way short of anything modern.
09:0016. And here is the mistake that gets made every single time somebody adds insulation themselves. They push it right
09:09out to the eave and block the vents.
09:1217. You need air coming in at the eaves and out at the ridge, moving through that attic and carrying
09:18heat away.
09:1917. There are little channels called baffles that hold the insulation back off the vent so the air path stays
09:25open.
09:2618. If you have put insulation in and your dams got worse, go and look at your soffits from outside
09:32and then from inside with a light.
09:3518. Blocked soffit vents are extremely common and almost nobody knows to look.
09:4219. Make sure nothing is deliberately blowing heat or moisture into that space.
09:4720. A bathroom fan ducted up into the loft rather than out through the wall or roof is doing exactly
09:55that and I went through what that does to a house in the video on windows running with water.
10:0120. Leaky heating ducts running through an attic are the same problem.
10:0521. So is a recessed light that is not rated to be covered.
10:1121. Understand the target because it is the opposite of what people assume.
10:1622. You are not trying to warm the attic.
10:1923. You are trying to make it as cold as the outside.
10:2224. A cold attic is a healthy attic because a roof that is the same temperature all the way down
10:28from ridge to eave has nothing to melt and nothing to refreeze.
10:3325. Everything on this list is in service of that one sentence.
10:3926. And do the easy diagnostic that costs you nothing, which is my grandmother's.
10:4526. The next morning after a snowfall, before the sun has been on it, go out and look at your
10:52own roof and then look at the others on your street.
10:5526. An even blanket of snow means a tight house.
10:5927. Patches, bare stripes, a clear line melted along the ridge, snow gone over one particular room, all of those
11:08are heat coming through and they tell you roughly where.
11:1227. Snow gone in a line over the ceiling of one bedroom is telling you about the insulation over that
11:19bedroom.
11:2028. That is a survey of your own house for the price of standing in the road in a coat.
11:2529. And the pattern tells you roughly where to go looking.
11:2929. Melted along the ridge and nowhere else usually means warm air collecting at the peak and not enough coming
11:37through to carry it away.
11:3830. Bare stripes running straight up the slope, evenly spaced, are following the rafters, which means thin or settled insulation
11:47between them.
11:4831. A round bare patch on its own is almost always a penetration, a pipe or a vent or a
11:56light fitting below it.
11:5831. A whole section gone while the rest holds its snow means something specific under that section and that is
12:06where I would start.
12:0732. None of that is a diagnosis you should bet money on, but it turns a vague worry into a
12:14place to put the ladder, which is most of the job.
12:1732. Now, if water is coming in right now and you need it to stop this week, there is one
12:23thing worth knowing.
12:2533. Fill a leg of an old stocking with calcium chloride, the ice melter sold for paths and steps.
12:3233. Tie the end and lay it across the dam so it runs up and down the slope rather than
12:38along it.
12:3934. You can push it into place from a ladder or from a window or with a long pole, and
12:45you do not climb onto the roof to do it.
12:4835. It will melt a channel straight through the dam and give the water behind it somewhere to go.
12:5435. Calcium chloride, not rock salt. That is a bucket under a leak. It is not a repair, and the
13:02repair is in your attic and you should do it in the spring when you can see what you are
13:07doing.
13:0836. And a word about being up there at all. Step only on the joists because the ceiling between them
13:16will not hold you and people do come through.
13:1836. Take a light and wear a mask because attics are filthy, and if there is old loose insulation up
13:26there that you cannot identify, especially a grey or brown pebbly material, do not disturb it and do not start
13:34pulling it about.
13:3537. Get somebody to tell you what it is first. I talked about that one in the video about home
13:42features you cannot build anymore.
13:4538. Now, who gains from this? Look at what is for sale against ice dams.
13:5139. Roof rakes. Heat cables that you screw along the edge of the roof and run every winter for the
13:58rest of the building's life.
14:0039. Gutter guards, which do nothing for this whatever. A removal service with a steamer, which does work and costs
14:08a good deal and will be needed again next year.
14:1239. And roofers, some of whom will quote you for a whole new roof.
14:1640. I am not telling you those people are crooked. A steamer crew genuinely gets ice off a roof.
14:2141. Heat cables genuinely melt a channel. And on a complicated roof with a valley or a dormer, where you
14:28cannot fix the cause, they are a reasonable answer, and I would not argue with anybody who fitted them.
14:3441. But notice where every one of those things is. They are all outside, on the roof, where the ice
14:40is.
14:4041. And the cause is inside, on the attic floor, in a few holes round a light fitting and a
14:46hatch that nobody ever sealed.
14:4742. There is no company coming to your door to sell you a tube of sealant and an afternoon in
14:52your own loft.
14:5342. There is no advertisement for that.
14:5542. So the entire visible industry sits on the side of the building where the symptom is, and the side
15:01where the cause is stays quiet,
15:0342. And a homeowner reasonably concludes that this is a roof problem because every single person who has ever spoken
15:09to them about it was standing on the roof.
15:1242. And notice the shape of the money. The things on the roof are bought again.
15:1642. Cables run every winter. A steaming crew comes every year. A rate comes out after every snowfall.
15:2243. The thing in the attic is bought once, and then it is done, and the icicles do not come
15:27back.
15:2843. One of those is a business, and the other is an afternoon, and you can see which one has
15:33the advertising budget.
15:3444. That is worse than a conspiracy, because a conspiracy can be exposed.
15:3944. Everybody involved is just selling the thing they know how to sell.
15:4244. And here is the thing I keep coming back to on this channel.
15:4545. That roof is telling you the truth every winter morning, and it has been telling you for years.
15:5145. The snow pattern is a picture of where your house is losing heat, drawn for you, free, by the
15:56weather.
15:5645. The icicles are a measurement. The dam is the bill.
16:0145. My grandmother was not clever for reading it.
16:0346. She was simply looking, in a time when everybody looked, because there was no furnace to take up the
16:08slack,
16:0946. And a house that lost heat was a house that was cold, and you found out about it the
16:14hard way the same night.
16:1546. We have spent 70 years building houses that hide their own faults.
16:1946. The furnace covers the heat loss, the paint covers the stain until February,
16:2347. And the roof looks exactly the same from the road, whether it is doing its job or not.
16:2847. And so a thing that used to be obvious to a woman in a buggy now has to be
16:32explained in a video.
16:3448. But the snow still works.
16:3648. That is what I find hopeful about this one, and there is not much on this channel I would
16:40call hopeful.
16:4149. Every other fault in a modern house has to be hunted for, with a meter or a screwdriver or
16:46a man you have to pay.
16:4849. This one puts itself on display, once or twice a winter, on the outside of the building, in daylight,
16:54where anybody can see it from the road without so much as opening a door.
16:5749. You have simply never been told that the picture means anything.
17:0149. Icicles are not a sign of cold. They are a sign of heat.
17:0449. So tomorrow morning, or the first morning after the next snow, go out and stand in the road and
17:10look at your own roof.
17:1150. Even white or patchy.
17:1350. Then look at the three nearest houses and see how yours compares.
17:1650. That is the whole job, and it takes four minutes, and it will tell you more about your house
17:21than anybody has told you in years.
17:2350. Then come down to the comments and tell me what you saw, yours against your neighbors,
17:27because I would like to know how many of you find out you are the patchy one.
17:3151. And tell me whether you have ever actually been up into your own attic, not peered through the hatch,
17:37been up.
17:3851. I suspect the answer for a great many people is no, and if that is you, you are not
17:42unusual, and you are in exactly the right place.
17:4551. Next time I want to go through the first hour of a power cut in order, because there are
17:49two or three things worth doing in the first 60 minutes that almost nobody thinks of until it is far
17:55too late to do them.
17:5651. Thank you for sitting with me. Go and look at your roof.
17:5951. The people who built this country with their hands knew that, and we are only just starting to remember
18:05it.
18:0552.
18:0552.