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Susan
Posted on Friday, January 12, 2001 - 04:31 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

My old slate roof develops the most incredible icicles and ice dams, particularly in the valleys. The eaves overhang about 2 feet so it is difficult (also called "stupid") to lean out the 2nd story window and try to break them loose. A few questions:
1) Does leaving the ice dams in place damage the slates?
2) Does knocking the ice down damage the slates?
3) Do you have any ideas what I can do to reduce the melting? It's probably an old house thing, but I'm not sure where to put insulation.

Thanks!
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Philip V. Hoad
Posted on Saturday, January 13, 2001 - 09:24 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Susan,

The reason you have ice dams is because there is too much heat loss from your house. The snow is melting and then re-freezing as it reaches the cold eaves overhang. You need to check your insulation and vapour barrier in your roof attic space.

Aggressively removing this ice can damage the slates.

Leaving the ice dams in place should not damage the slates but will damage the wood deck underneath if the underlayment is inadequate.

Philip.
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Eric
Posted on Tuesday, March 06, 2001 - 06:43 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

My wife and I recently moved into a home with a slate roof. This winter has seen alot of heavy, wet snow. As the snow accumulates on the roof, it eventually comes crashing down in large sheets.

Is this usual for slate rooves? I have not noticed excessive icicles or any ice dams (it all falls off before it dams).

Any suggestions appreciated.
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Joe Jenkins
Posted on Wednesday, March 07, 2001 - 12:11 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

This has been a bad snow year and ice and snow have been problems for all roofs. You can stop the snow avalanches by installing "snow guards" on your slate roof. You can locate them on the internet via a search engine, or look in the Slate Roof Bible. Also, make sure your roof is properly insulated to avoid excessive ice build-up along the drip edges.
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Susan
Posted on Sunday, March 25, 2001 - 02:26 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Joe, how do you insulate the roof? The previous owner put some in part of the attic floor, but mutilated the tongue-and-groove flooring in the process. I suspect most the heat is coming up the walls. Is there a "best way" to insulate?
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Joe Jenkins
Posted on Monday, March 26, 2001 - 12:44 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

It depends on whether you want to use your attic space as a living space or not. If not, you can insulate your attic floor, otherwise you have to insulate the rafters. If the floor is insulated, the attic must be ventilated (out gable end windows or louvered shutters). If the rafters are insulated, there should be an air space (1/2" or 1") between the insulation and the roof sheathing, and maybe some soffit vents and gable end vents or roof vents to allow for some air flow or breathing. Also, if the rafters are insulated, there should be a vapor barrier (sheet of plastic) interior to the insulation (under the wall board or paneling).
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Jim Bennette
Posted on Thursday, November 29, 2001 - 01:18 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Here in Massachusetts the new code requires Ice&Water Shield. on some of our restorstion jobs we removed slates at eaves and applied ice shield to roof decking and then reinstalled the same slate uselly with a new copper gutter or dripedge.
good insulation on the attic floor with no voids such as those notorious pull down attic stairs etc
is also very important.
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Walter Musson
Posted on Friday, January 04, 2002 - 09:23 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Here in Maine we also have lots of ice damming.One house I maintain has wide overhangs with exposed rafter tails just two boards thick.There is no soffitt to ventilate this area. It just stays cold so if the sun melts any snow on any given day and it runs down the roof ,it just refreezes when it gets down to the eaves.I've had to physically remove the snow and ice last winter.In the spring we're going to pull the last three feet of Monson slate and relay over Grace Ice and Water Shield.Its also a hip roof so venting the finished attic is not easy even though the insulation is adequate.
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Kevinsky
Posted on Tuesday, August 19, 2003 - 04:22 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I am in the process of hiring a slate contractor to repair / replace several broken roof slate for my garage roof. My question is:
which one is better method in covering the nails after the replacement: using aluminum / copper flashings (bib?) or silicon rubber. The reason I asked is because if we use the flashings we are uplifting the slates so there will be a space in- between slates and this is not good. Slates are supposed to be really "flat" or directly on top on each other. And some people said that the flashings will slide down after a while. What do you think?
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Kevinsky
Posted on Tuesday, August 19, 2003 - 04:27 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Are the snow guards important? one of my slate contractor said that he will not and cannot put the snow guards back as originally located:
1. it is impossible or maybe too difficult
2. they are not very functioning

Are they true? Should I keep the snow gurads? If I should, how can the contractor put them back or can they work without taking out the guards?
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Joe Jenkins
Posted on Tuesday, August 19, 2003 - 10:17 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Do not use silicon rubber in place of bibs. The bibs should not lift the slates in any detectable manner.

Snow guards should be used where there is the threat of ice and snow avalanches falling on and damaging such things as pedestrians, cars, or lower roofs. If these threats do not exist, then you can leave the snow guards off.
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Anonymous
Posted on Wednesday, August 20, 2003 - 10:56 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I have a slate roof, about 60 years old in need of some repairs. There was a leak behind the chimney (flashing pulling away) that I had repaired last year by a guy who wasn't exactly professional. He applied tar and a membrane, instead of removing and replacing the flashing. It looks pretty bad from the street. So I've had some estimates from others, and I'm getting conflicting stories.

Should I forget about the flashing behind the chimney as long as it doesn't leak? Or should I have it re-flashed with copper like the original?

There are some loose slates. One roofer wants to just slide new slates in under the existing, nail them (copper nails), and caulk over the exposed nail heads. Another has a galvanized bracket that slides under the existing slate and is pointed so that it pounds into the roof. It has a hook on the bottom to hold the new slate. Which method do recommend?

Should I consider ridge rolls? This is a flashing that would cover the seams in the roof. I don't have a problem with leakage now, and I think this shiny flashing will detract from the roof's appearance. But some of these guys insist that this is what I need.

What about flashing around vent pipes? The original is still up there and not giving me any problems. Is this likely to corrode and cause problems in the future?

Sorry this list is so long, but I think there is a lot of bad advice out there. I will appreciate any advice you can give me.
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slateworks
Posted on Wednesday, August 20, 2003 - 08:39 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Hi, Yes your flashing should be replaced for protection from leakage in the future..Copper would be a good choice for durability and looks..The slate hooks are a good choice for repairing the slates that need replaced,You really should avoid face nailing the slate if possible..Your roofer shuold use a slate ripper to remove the nails and damaged slate,install the slate hook,then install the replacement slate,size and color to try to match your existing slate as close as possible..Ridge iron on your peaks is okay,(once ridge irons are installed unless they are aluminum(they are to light a gauge to use ,do not recommend)they must be painted every 8-10 years ect.)but it sounds like you prefer the way your roof looks without it,If the peaks of your roof are not leaking then I would leave them be,If your roofer is up there they can inspect them to see if they are any voids that might cause a problem..--Or if you wanted to you could have your roofer point or caulk your hips with a good quality roof cement or urethane caulk,this does take a little bit of time and patience to do a nice neat job,you do not want the bead to wide or wavy.
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Joe Jenkins
Posted on Thursday, August 21, 2003 - 06:53 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

If you're going to use slate hooks, use stainless steel ones, not galvanized. Galv. hooks will rust and stain your roof.

The copper ridge roll will be shiny only for a couple weeks. Then it turns dull brown.

Never face nail replacement slates.

Read the Slate Roof Bible.
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peter v.
Posted on Tuesday, February 03, 2004 - 03:59 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

my sixty year old house has a slate roof. This has been a horrible winter, and we have a lot of ice on the north side of our house, and the gutters are filled with ice. There is staining on the outside of my house walls, indicating that the roof is leaking about a foot up from the gutters. When my roofer comes to fix this, will he have to replace the wood under the shingles? one roofer has proposed replacing the whole roof with synthetic slate over plywood, but after reading this website, i am very leery of same. Help!
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peter v.
Posted on Tuesday, February 03, 2004 - 03:59 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

my sixty year old house has a slate roof. This has been a horrible winter, and we have a lot of ice on the north side of our house, and the gutters are filled with ice. There is staining on the outside of my house walls, indicating that the roof is leaking about a foot up from the gutters. When my roofer comes to fix this, will he have to replace the wood under the shingles? one roofer has proposed replacing the whole roof with synthetic slate over plywood, but after reading this website, i am very leery of same. Help!
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Walter Musson
Posted on Tuesday, February 03, 2004 - 04:07 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Peter,
Do you have built in gutters or detached half round gutters?You can have the roof repaired without changing the whole thing over to an imitation slate.It sounds like they might want to "plus sell" you on something that really isn't required.
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admin
Posted on Tuesday, February 03, 2004 - 08:03 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Better check your roof insulation as well. It probably needs improved.
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peter
Posted on Tuesday, February 03, 2004 - 09:26 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Walter, I have detached, half round gutters which are a year old. I agree, the more I look into this subject, the more I realize that I should have the roof repaired, nor replaced. I may have the south half completely re-done, and then use the good salvage to repair the north side. I will have to see. This website has been a tremendous help. and thanks, admin for the advice about the roof insulation. peter
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Donald J. Ouimet
Posted on Wednesday, October 06, 2004 - 11:39 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I have a slate roof on an old Victorian house with about 6 valleys and I get ice dams that loosen and damage the slate around the lower valleys. I was going to have a slate guy redo the lower valleys with a snow belt of aluminum .025 4FT on each side of the valley. Will that solve my problem.
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admin
Posted on Wednesday, October 06, 2004 - 12:31 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Why aluminum? We recently replaced valleys with 20 ounce copper and installed a standing seam 20 ounce copper snow apron on a Victorian house - on all eaves. You can see the photos at http://www.jenkinsslate.com/install_snow_aprons.htm. Copper can be soldered in complicated areas, aluminum can't. Standing seam doesn't need to be soldered, but if you have a difficult area, you may have to solder some pieces together.

Joe Jenkins
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Dom
Posted on Friday, July 29, 2005 - 04:41 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

This winter I had ice daming on my 2 year old slate roof. A new contractor came, looked at the roof and because the leaks were near valleys, believes that the valleys were installed improperly. They are closed valleys with a continuous sheet of copper underneath as opposed to sererate sheets under each row of slate. What do you think?
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Spencer P.
Posted on Friday, July 29, 2005 - 09:37 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Installed wrong. The ONLY way to do a closed valley on a slate roof is to step flash each row of slate, as you would around a chimney. water/snow/ice will get between the slates where they meet together at center point of valley and run on copper, with a continuous sheet of copper the water will find a nail to leak thru, with step flashed method it will (water) drain at each slate NOT finding a nail hole to leak thru. It looks like you will have to replace the valley's. That is way this site is SO valuable to future slate roof owners so hopefully they can educate themselves and avoid these problems from happening. Thanks Joe for this site. Spencer P.

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