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Old_school (Old_school)
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Username: Old_school

Post Number: 1151
Registered: 01-2009
Posted on Monday, November 23, 2015 - 09:09 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Damnuke, If you get the right coatings, it will seal all of the slate and the capillary action will be taken right out of the picture. It is like putting a liquid tarp over the roof. I just hope it doesn't cause other problems. As you say though, you have o=nothing to lose.
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Damnuke2002 (Damnuke2002)
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Post Number: 8
Registered: 11-2015
Posted on Monday, November 23, 2015 - 11:18 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Hi Victor I was planning on next dry patch of weather to seal roof with acyrlic polymer, hence this will make the tile even smoother I assume? Although they are very smooth tiles. I thought nothing to lose as other alternatives very expensive. Thanks once again Dave
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Vcardenes (Vcardenes)
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Username: Vcardenes

Post Number: 14
Registered: 03-2015


Posted on Monday, November 23, 2015 - 07:55 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Capillarity largely depends also on the surface of the tile. For regular, smooth surfaces, capilarity is higher, while for rough surfaces is lower. This is because the water needs to close surfaces to climb, if the surfaces perfectly match the capilarity is higher than if the surfaces do not perfectly match.
Victor Cardenes
roofingslate.wordpress.com
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Damnuke2002 (Damnuke2002)
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Post Number: 7
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Posted on Friday, November 20, 2015 - 10:45 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Cheers Victor,
I will have an experiment with the capillary test. will be interesting to see what results 15 degrees display?
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Old_school (Old_school)
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Username: Old_school

Post Number: 1150
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Posted on Thursday, November 19, 2015 - 05:37 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Victor. that is a brilliant visual of the problem. John crookston
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Vcardenes (Vcardenes)
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Post Number: 13
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Posted on Thursday, November 19, 2015 - 08:25 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Here is a sketch on how to measure the capilarity

Victor Cardenes
roofingslate.wordpress.com
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Damnuke2002 (Damnuke2002)
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Posted on Thursday, November 19, 2015 - 03:19 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Thanks Old school your knowledge is much appreciated, If not anything i have learnt quite a bit about how not to slate a roof. I think for now due to limited funds I will have to look at a temporary fix of some sort of sealant coating I just hope I can get a sealant which will seal the overlap gap. re you aware of any translucent acrylic polymer products out there I could try? I appreciate you in the US and me in the UK. Thanks Again
Dave
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Old_school (Old_school)
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Username: Old_school

Post Number: 1149
Registered: 01-2009
Posted on Wednesday, November 18, 2015 - 07:37 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Damnuke, FYI, "Standing seam" is a metal roof with the vertical seams locked together so that the water runs in the channels between the ribs. It is very efficient for this type of roof, but the problems like all roofs occur at the walls or around penetrations, (skylights, pipes etc.).

The slate is designed for a bit steeper pitch as you know and the only way to make it work on something like what you are dealing with is to lay it so that the vertical overlap of the slates (the headlap) is almost excessive. The water wants to wick back beneath the slates, and it will, but the steeper the pitch is the more gravity holds it back. On a vertical wall for instance you could get away with almost no overlap of the slates. On a flatter roof like this, you need more overlap, and since they are already installed that is impossible.

As Kwhord said, if you had really big slates and a big overlap you could get away with it. To explain, suppose you had a large piece of slate that covered your whole roof; No joints, no leaks. Outside of taking everything off and redoing it, you only other option would be to coat it with something to seal it all up. There will be consequences in the short and long term, but from the sound of it, you are not going to be hurting anything more than it is already. Perhaps you could spray on a acrylic polymer coating over the slates. It will definitely work, but not indefinitely. good luck with this one. If you want to email me I could talk you through it.
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Damnuke2002 (Damnuke2002)
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Post Number: 5
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Posted on Wednesday, November 18, 2015 - 03:49 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Hi Fellas, this in in UK, Wales (lots of rain this time of year!) The slates are nailed in and the damp patches are in lower corner of room (side attached to building) and in various spots some below skylight. just to give you an insight the roof has slate, felt sarking board and then selotex, so hard to track where water actually originating from? sorry Kwhord not quite sure what you mean by a 'standing seam'? I know its far from ideal but unless i suddenly find a lump of dosh looking for any type of fix, so do you think i could get away with a sealant painted all over tiles especially under overhang of tiles. thanks again for your tile all
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Old_school (Old_school)
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Post Number: 1148
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Posted on Tuesday, November 17, 2015 - 10:15 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Where is this building located? Are the slates nailed or are they clipped into place? Does it just leak along the bottom, or around one or both of the skylights? They look like pretty thin slates. Is this in France? Just curious. More info please.
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Kwhord (Kwhord)
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Posted on Tuesday, November 17, 2015 - 11:54 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

super-big slates with giant headlap and side you can get away with it depending on conditions. generally frowned upon at that pitch..

traditional standing seam is a great application to low pitch
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Damnuke2002 (Damnuke2002)
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Posted on Tuesday, November 17, 2015 - 07:52 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Hi Guys, gere are few pics of the aforementioned roof. Generally the build is good, its just the pitch is far to low aghhh!pic1 pic 2
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Old_school (Old_school)
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Post Number: 1147
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Posted on Monday, November 16, 2015 - 09:03 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Victor, Thanks! How neat and old it is. It looks like it could use some repairs now. Any good slate guys over there? Just kidding!
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Vcardenes (Vcardenes)
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Post Number: 12
Registered: 03-2015


Posted on Monday, November 16, 2015 - 09:47 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Here are the pictures, taken in Montefurado, Galicia, Spain.



Victor Cardenes
roofingslate.wordpress.com
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Damnuke2002 (Damnuke2002)
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Posted on Monday, November 16, 2015 - 04:23 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Thank you guys for your knowledge and thoughts on this, yes it is a problem which has really been worrying me. I will get the pictures up by end of today. I will also capilary test. There seem to be lots of clear sealant products out there from what you say not an ideal solution but better than nothing unless i replace all the tiles with the interlocking type of roofing. thanks really appreciate some proper advice at last!
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Old_school (Old_school)
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Username: Old_school

Post Number: 1145
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Posted on Friday, November 13, 2015 - 10:21 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Hey Victor, Could you enlarge your picture of the cone spire slate roof below your name on the post. I am trying to figure out what that is and how bit it is. Old School
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Vcardenes (Vcardenes)
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Username: Vcardenes

Post Number: 11
Registered: 03-2015


Posted on Friday, November 13, 2015 - 10:05 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

An old method to measure capilarity is to put two slates together in a bucket with two inches of water. After one day (or so), take the slates and just look how high the water climbed up the slate. Then you can see exactly the potential danger by capilarity you have. You can do this at different angles, reproducing the geometry of your roof.
Also, I agree with Old_school, using sealants in a slate roof is not a solution.
Victor Cardenes
roofingslate.wordpress.com
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Old_school (Old_school)
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Username: Old_school

Post Number: 1144
Registered: 01-2009
Posted on Thursday, November 12, 2015 - 06:45 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Does it need to breathe No, but then again it depends on how long you are talking about. 3 weeks, 3 months, 3 years, 3 decades? Everything and action has it's consequence. As a last resort, a sealing product over the top of the slates may work for while, but you have to remember that the slate is supposed to be the "sealer" People put a lot of things beneath the slates and all different types of roofing to try and "seal" the roofs, when the roofing product is supposed to do that job. For years we used to install asphalt shingles directly to the deck without felt, and since the houses were not all that tight and insulated, it worked just fine.

As an example, you could stretch a tarp over your roof and that would "stop" the leakage too, for a while. You have a real problem, not of your making, and like I said before, we will have to wait for your pictures to see if there are any other ideas. Cheers!
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Damnuke2002 (Damnuke2002)
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Posted on Wednesday, November 11, 2015 - 03:32 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Thanks Old School, I will sort some pics out this week and post up. The invisible gutter is basically a piece of fibre glass shaped liked a shallow gutter running on one side of the roof where I had the main damp patch. I have found some sealant paint which is clear (Adseal) I know its not ideal solution but hoping it may prevent the capillary action which seems to be the problem? I dont know much about roofs but learning everyday now thanks to you guys, does the roof need to breathe? apprceiate your time thanks Dave - UK
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Old_school (Old_school)
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Username: Old_school

Post Number: 1143
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Posted on Tuesday, November 10, 2015 - 10:38 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I am having a hard time "getting" the picture. Could you take a few and post them for us to see?

There is nothing you can do about the pitch of the roof. 15 degrees is about 4/12 pitch and that is really too flat for slates. You could lay them with more headlap, but the are already on the roof. I don't know what you mean by and "invisible gutter" Do you mean a built in one? A few pictures would be of great help. Cheers!
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Damnuke2002 (Damnuke2002)
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Username: Damnuke2002

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Posted on Tuesday, November 10, 2015 - 09:13 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Any advice would really be appreciated. We purchased a house which was only a few years old. all looked good until the rain visited. Patches of damp appearing in several places. particularly one corner, anyways to cut a long story short we found the pitch was far to small about 15 degrees where it should be at least in its mid 20's we were told (not sure how it passed regs and a different roof was constructed) we now stuck with this roof. We were told there are particular interlocking tiles available but expensive to replace whole roof. We had an invisible gutter installed under slate which has improved but still small patches when heavy rain. My question being is there a sealant solution which could be sprayed on the slate tiles or another suggestion which would prevent the capillary action which seems to be the problem? Thank you would be grateful for any advice - cheers Dave P-P

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