Ever seen this ventilated ridge

[SuperJohnG]

Has anyone ever seen this ventialted ridge system?

 

Roofing merchants dropped this off to see how it fitted. I am looking for a dry ridge ventilated system. So this cocrete ridge tile sits on these plastic bits which will rest on the slates and a seperate, but all be screwed together with a strap over the top between each ridge tile. I think it's sandtoft but have never seen it before. He reckons using this you don't need to roll out membrane bit.

Has anyone used this or seen this?

 

Keen to see if its any good or a load of rubbish. 

Slates obviously still to go on.

 

Edited August 12, 2021 by SuperJohnG

[PeterW]

Looks like Weinerberger Profile Dry ridge - you still need the membrane lapped up and over the ridge. 

[SuperJohnG]

9 hours ago, PeterW said:

Looks like Weinerberger Profile Dry ridge - you still need the membrane lapped up and over the ridge. 

I thought that, air should still flow well through through the membrane I assume, I do have two membranes as on one SIPS panel, then on one top of sarking.  

[DragsterDriver]

Looks good- I really don’t like the adhesive ones  

[makie]

Marley used to have one like this, works well but as someone else said it needs the membrane

[Ferdinand]

Quite like the idea of a "ventilated ridge".

 

Suggest Striding Edge, or the Black Cuilin.  Very well ventilalted, those two ?.

 

[Redoctober]

@SuperJohnG the set up in your photos appear to be just like the set up we have on our roof / dormers. Ours is a Scottish build and have had no issues with it at all.

[SuperJohnG]

10 hours ago, Redoctober said:

@SuperJohnG the set up in your photos appear to be just like the set up we have on our roof / dormers. Ours is a Scottish build and have had no issues with it at all.

Thats good news . Interestingly what soffitaterial.is that @Redoctober thats something I need toneort also

[SuperJohnG]

14 hours ago, Ferdinand said:

Quite like the idea of a "ventilated ridge".

 

Suggest Striding Edge, or the Black Cuilin.  Very well ventilalted, those two ?.

 

The are just hills.....wee tiny things! 

[Redoctober]

Sorry @SuperJohnG, I have no idea. I have checked my paperwork relating to the roofer but his quote just stated supply and fit "dry ridge system with bockends".  Beyond that I have no idea!! ?

[SuperJohnG]

2 hours ago, Redoctober said:

Sorry @SuperJohnG, I have no idea. I have checked my paperwork relating to the roofer but his quote just stated supply and fit "dry ridge system with bockends".  Beyond that I have no idea!! ?

Ah no that was my bad typing. What wood was that you used for the soffit? Looks nice and similar to what I am trying to achieve. 

Edited August 14, 2021 by SuperJohnG

[Redoctober]

@SuperJohnG having looked at my paperwork from the TF cit appears company it appears they supplied and fitted the following -

 

195 x 25mm redwood fascias.

145 x 25mm redwood barge boards

9.5mm OSB eaves tilt boards

9.5mm exterior grade [plywood soffit boards

45 x 45mm soffit bearing timbers

T&G lining boards to exposed soffit areas 

 

I hope all this helps and makes sense! ?

 

[SuperJohnG]

2 hours ago, Redoctober said:

@SuperJohnG having looked at my paperwork from the TF cit appears company it appears they supplied and fitted the following -

 

195 x 25mm redwood fascias.

145 x 25mm redwood barge boards

9.5mm OSB eaves tilt boards

9.5mm exterior grade [plywood soffit boards

45 x 45mm soffit bearing timbers

T&G lining boards to exposed soffit areas 

 

I hope all this helps and makes sense! ?

 

Thanks @Redoctober much appreciated 

[SuperJohnG]

I still seem to be mega struggling with this weinerberger bit, I quite fancy getting it. However the supplier has just advised the price is £85 plus vat for 2.7m, so in the end it is around £1360 for the 40m I need plus, ridge tile at around £3.5 a pop, makes it horrendously expensive for a ridge. 

 

The reason he was offering this was they cant get an angled ridge tile to suit my 90 degree apex, which seems a little crazy, but he says it is quite a steep pitch but this helped use a tile for s lesser pitch but allow it to clear the apex.

 

Now I had reverted back into my shell and started to go back to a zinc ridge (ventilated( - which i don't want but at 400 quid it is much better priced. He is looking for the right ridge tile but its a bloody struggle to get these in under 18 weeks it seems. 

 

 

However I have now stared to question how the air gets out up here, at the ridge, and what's required in terms of air flow. 

 

The over fascia vents are 25mm and will allow lots of air in under the membrane and in between the sarking and SIPS panel (which also has a membrane) but at the top the the membrane is still lapped over the sarking, now as per @PeterW mentioned above that should be the case.

 

But in the event I use the weinberger profile should I put a cut in the membrane to let the air out? everything will be covered with just air allowed in at the side vent as per the first picture. I know the membrane is vapour permeable, but it is windproof so wont allow a nice flow of air so do I need that really good flow or will the vapour permeable but do it? 

 

Also - there is a possibility he can get the right ridge tile to suit my pitch and in that case - it seems i can revert to a roll out dry ridge. Now If i do that - shoudl a cut the membrane allow air through then roll out the dry ridge roll, or is it just like a bit of membrane? or does it allow a lot more airflow while keeping the beasties out? 

 

help please - end of my wits with no solid advice. 

[dpmiller]

Uni ridge  plus rollout dry ridge?

 

https://www.sigroofing.ie/products/clay-tiles/siga-clay-tiles/dura-ridge-tile-overview/

 

we got ours from LBS but it's the same product.

[markocosic]

You should not have lots of warm moist air coming through your sip. (if you do then you have a problem - sip needs to be airtight internally to not transport a bucket load of moisture into three OSB)

 

Your structure should be less vapour permeable inside (vcl) than it is outside (membrane). So that it dries out much much faster than it gets wet.

 

If moisture did get through the OSB then it should be allowed to escape more easily through the membrane than it is to get through the OSB (it will be, unless you're using plastic sheet as a membrane)

 

If water comes through the roof covering it shouldn't get to the sip. (Which it won't as the membrane is breathable but waterproof)

 

So I'd say:

 

Don't worry about ventilation between sip and membrane. (so no cuts where I think you're asking about cuts - membrane is continuous from eave to eave and any moisture under it...breathes through it...non issue)

 

Do worry about ventilation between roof covering and membrane. (so vented ridge)

 

Answers world be different if the membrane wasn't breathable. Then I'd say good need to vent it with cuts at the to.

 

 

Be thankful that you're not in ice damming areas:

 

https://www.buildingscience.com/documents/insights/bsi-046-dam-ice-dam

[markocosic]

Just looked at photos and see that my advice might be unhelpful.

 

I imagined a membrane on the sip for water shedding purposes - draped between vertical battens so that water doesn't pool on your battens - then vertical battens on top of that plus horizontal counterbattens and a roof cover.

 

You wouldn't vent under the membrane. (So no cut at the top)

 

I think you *would* vent on top of the membrane (and out through ridge) though.

 

Are you imagining a second membrane here? I can't see why you would be asking about cuts otherwise.

 

 

 

[markocosic]

sketch of what I had imagined the layup to be

[markocosic]

This useful?

 

https://www.wienerberger.co.uk/content/dam/wienerberger/united-kingdom/marketing/documents-magazines/technical/UK_MKT_DOC_TEC_ROF_SAN_Dr_John_notes_roof_space_vent_001.pdf

 

You're a sip structure?

 

Therefore it MUST be well sealed warm roof so that the SIP doesn't turn into wet Weetabix

 

Therefore the breather membrane that you have already that's lapped over the top is sufficient.

 

And in theory no ventilation whatsoever if the roof can breathe (e.g slates with gaps not a standing seam metal roof) unless you're trying to keep the roof cool enough to avoid ice dams (in which case steep roof and lots of breathing above membrane and out of the ridge, and try to avoid breathing in warm air from walls that are heated by the sun etc)

 

 

If you propose having another membrane above sarking, then battens, the roof finish, with all ventilation above the second membrane, then it's fine to lap this second membrane over the ridge just above sarking.

 

When we were looking at SIPs the detail requested was a breathable membrane over the sip (one suitable for direct contact) right over the ridge; then vertical battens; then either counterbattens and standing seam or counterbattens and tiles or OSB and asphalt shingles etc; with ventilation between membrane and the roof finish at eaves and ridge levels. No additional membrane above this. The SIP folks would provide said membrane held in place with the vertical battens.

 

I don't see why you'd have a second membrane of this is effectively what you have. Tiles and ridge just go on. Sarking kinda overkill given that there's already OSB there for shear strength in the roof unless I'm missing something?

 

 

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