Leaking 15 degree roof with Velux windows and Sandtoft 20/20

[noseall]

Santoff 20/20 get a 15 degree rating due to the interlocking design, so surly if you are stacking them on top of one and other i.e. between sky lights then they must revert back to plain tiles needing a much greater pitch.

Yeah but sandtoft 20/20 are interlocking.

I'm of the opinion that if you are going to design a tiled roof with a very low pitch then the roof needs to be very simple with no complex interferences at all.

I.E. a lean-to pitch slab of a roof with no valleys, no dormers, no velux, no nuffink. Interrupting the flow of water on these bonkers pitches is asking for trouble.

Designers need to understand that either they go with a flatty or make the customer aware that the roofer needs to be top notch-super conscientious.

 

[catlad]

I agree with you but if you look at the picture, they are just stacking them on top of each other between the sky lights and there is no interlocking going on there.

 

[hardmetalking]

Tiles aren't made for that pitch, there are several options but tiles aren't one of them!
I've heard so many bodges over the years, doubling the felt isn't a solution it's a bodge.........
Why oh why oh why oh why are people happy to spend money on every other part of their house but when it comes to the roof they want to skimp as much as possible??
Rant over sorry if I have offended anyone.
Zinc would last forever and NEVER leak
We are currently installing zinc soffit, fascia and gutters to 3 new properties selling for £1.6m each and they have sandtoft 20/20 at 15 degrees and yes.........they LEAK!
I'm sure they work well on a straight forward roof with no hips, valleys roof lights etc but on a complicated roof you need a specialist product.

 

[datarebal]

interesting, I stripped out a couple of zinc vallies last week in Carshalton..they were leaking and had been for years,,

 

[hardmetalking]

Don't suppose you have any pictures? It should have been a real pain to take out, was it? Can't really understand how a zinc valley leaks?? If installed correctly

 

[freddiemercurystwin]

If installed correctly

And therein applies to every kind of roofing material available, they al work if installed correctly and within the limits they are designed for.

 

[hardmetalking]

My point exactly Freddy! I can't understand why people are constantly pushing the limits of materials, wonder why they fail and then look for a cheap fix??
You pay your money and you take your chances.............

 

[datarebal]

Actually it was a little fiddly with clips and the like. they were fitted in lengths of approx 2 mtr and a remainder at the top of around 900mm. nail fixed at the top under the lap the top sections at ridge board., sides had turn up with clipping both sides. no exposed fixings.

No pics i'm afraid.. this time!! There are many in the same street that have all been smarmed up with ****.. maybe get another or two.

In the past i have replaced holed zinc flats, hundreds of zinc soakers..
A good product but not without its limitations it seems.

 

[hardmetalking]

Very interesting.....
Sounds like a proper job but can't understand how it failed?
Maybe should of had a soldered ridge saddle.
The jobs that fail are usually down to installation or design, I've only seen the product fail once and the zinc was 124 years old!

Has the zinc actually failed or is it the junction with the tiled roof?

 

[sskryten]

Sandtoft 20/20 tiles have a min pitch of 15 deg

Now read the info on Velux flashings!!!!

You have two options for flashings for the 20/20 tiles....the standard EDZ but the min pitch for these are 20 deg if you need a lower pitch use the EDW flashing kit, these can be used at 15 deg.

When I fit velux windows I always try and dress up the Tyvek or whats ever there up the sides of the window frame. Seal/Stick the Tyvek joints with a good quality tape to the frame, and butt up tile battens as close to the velux as possible.
When tiling, try to avoid narrow cut tiles and use Left and Right hand Verge tiles. Yes they are three times the price but being wider they are easier to fix. It is possible to re-drill them so that you don't nail through the channels in the velux flashings.

Steve

 

[aveatry]

So the pitch is 15 but the tiles at the top of the velux are siting on a batten and kicking up meaning that these tiles are much lower than the 15 of the rest are they not ?.And because they are very smooth the wind is blowing the water up under. This should not be a problem because you also have the tyvek ---but do I see a rip right inbetween the windows.
Also when the tiles are cut to fit inbetween the windows they do look very open to the sides--wouldnt you be better with lead inbetween the windows.
Not an expert not a roofer, I have a pitched roof -bigger pitch with different tiles and remember when looking into the velux flashing kit - you have to get the right one for your tiles also

 

[Regencyroofingipswich]

I would be looking at the lead flashings joining the wall at the top personally.

I suspect water getting in through crap flashings or pointing, hitting the felt underneath and running in at the top of the windows where the felt has been cut.

 

[noseall]

I would be looking at the lead flashings joining the wall at the top personally.

I suspect water getting in through crap flashings or pointing, hitting the felt underneath and running in at the top of the windows where the felt has been cut.

Yeah, i had similar thoughts....

My guess is that the problem is occurring elsewhere and that the Velux opening is the first weak point on the way down.

I would use a garden hose with an accurate nozzle and spray water locally to positions on the roof, starting from low to high.

 

[radekski67]

Hi just wondered if you did ever resolve this problem with your velux windows and sandtoft tiles?? Cheers

 

[Number1mum]

Hi....just wondered if you have solved this problem. We too have sandtoft 20/20 and velux windows....im no expert but i cant see the "transverse drainage channel" above the velux. This is a piece of metal that comes with the velux that is fitted above the window in the membrane at an angle so that any water that comes in above the window drains down the membrane at the side. Did you have any problems with getting the tiles to sit flat next to the velux? We are having problems with aformentioned so any tips would be great.