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Velux onto sarked Roof


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Morning

 

another stupid question

 

I'm looking to install two velux windows onto a roof with 22mm sarking boards over 25mm battens.

 

the velux windows have a gutter at the top, run at a slope.

 

The instructions show the cutting out of batten/counterbatten so there is none, with the gutter sitting directly on roof screwed into rafters.

My roof makeup is sips panel, 25mm batten at 600 centres and then 150mm wide sarking boards.

 

so without being up there and trying it out I'm struggling to see what to do here. do I put the gutter just on top of the sarking board, which means its higher up the window than shown below,

 

do I remove the sarking board/part of it to attached to the batten below which would be at the same depth on the window as picture below,

or removed sarking board and batten and have it at a lower depth.?

 

confused. help appreciated.

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The diagram shows the roof as being batton  but your roof is sarking ? I would double check with velux that your starting with the right kit. Its really straight forward as everything should be self explanatory...... I have done 3 into sarking a few months ago, will see if I can find the info. 

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I am curious as to why your spec has the sarking over the battens. Our TF warm roof is sarked with the roofing fabric directly on the sarking and the counter battened and battened on top of that and then slated.

 

We have Fakro room lights and you need to choose the frame model and mounting kit depending on the covering profile, so you need to choose the correct combination for a top sarked profile.  I assume that the same is the case for Velux.  Your figures are for a batten over sarking profile.

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4 hours ago, bassanclan said:

Without battens to fix the slates to, how will you know you are not running out of true/parallel?

I presume you have to ping lines on the sarking and hope they line up with the battens underneath.

 

That's what sorts the men from the boys??

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On 24/05/2018 at 09:25, Tin Soldier said:

Roof Panel Makeup from top to bottom.

 

Slates

Membrane

Sarking

Battens

Fabric

SIPS Panel

Intrested to know what the fabric is as on a standed Scottish roof the breather membrane goes on top of the sarking, that way if you get a leak then the roofing membrane is there as the emergency layer. My roof is 

slates

membrane

22mm x 150mm sarking boards  

‘main roof timbers  

 

i dont have battens as the slate is reclaimed and vary   in size (a traditional style) from the biggest / longest slates at the bottom of the roof and the smallest slates at the top. 

There is then a 50mm ventilated gap below the sarking before the insulation. 

 

But as usual there is a dozen ways to skin a cat and I am just interested in your build up and the solution to the velux installation. 

 

 

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so, the SIPS panels company threw up the panels and wrapped the house in nilvent on walls and daltex roofshield on Roof

 

I didn't expect membrane to be put on at all so when questions the manager said

 

Yes membrane is on, but you'll have to batten at 600 centres to leave a ventilation gap, then sarking board on top.

I've put a second layer of membrane on the sarking (or I will once finished) as the roofshield has plenty holes it in where the lifting straps etc for the roof panels were cut off.

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  • 2 years later...

@Tin Soldier I'm undertaking this very task of planning at the moment to get the rooflights right. I have the same build up planned as you, I'd be interested to hear how you got on in the end? and also what you done with the rooflights if you have an update? 

 

I have combination L profiles in my design (Rooflights that link up with walls on the window, but planning the structural openings is a complete PITA.  

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  • 11 months later...
On 09/02/2021 at 22:36, SuperJohnG said:

@Tin Soldier I'm undertaking this very task of planning at the moment to get the rooflights right. I have the same build up planned as you, I'd be interested to hear how you got on in the end? and also what you done with the rooflights if you have an update? 

 

I have combination L profiles in my design (Rooflights that link up with walls on the window, but planning the structural openings is a complete PITA.  

How did you do it John?

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On 10/01/2022 at 01:29, eandg said:

How did you do it John?

Hi 

 

I threw those gutter bits in the bin. Lol. 

Now looking at it, they could have went at the SIPS panel level under the membrane as per above to get water that runs down the inner membrane. 

 

The rooflights are fitted to the sarking, which is on battens, I have membrane in the SIPS panel and on sarking so in reality hard to fathom water getting in and being an issue also having no metal gutters like that at the level below would be just like having a normal trussed roof in Scotland with sarking. 

 

 

 

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1 minute ago, SuperJohnG said:

Hi 

 

I threw those gutter bits in the bin. Lol. 

Now looking at it, they could have went at the SIPS panel level under the membrane as per above to get water that runs down the inner membrane. 

 

The rooflights are fitted to the sarking, which is on battens, I have membrane in the SIPS panel and on sarking so in reality hard to fathom water getting in and being an issue also having no metal gutters like that at the level below would be just like having a normal trussed roof in Scotland with sarking. 

 

 

 

Was it straightforward for your joiners to fit? I'm looking at roof openings just now and advice on another thread is not to go with the Velux standard as 10mm either side works - what did you do (and how did you make it as airtight etc. as the rest of your windows)?

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47 minutes ago, eandg said:

 

Was it straightforward for your joiners to fit? I'm looking at roof openings just now and advice on another thread is not to go with the Velux standard as 10mm either side works - what did you do (and how did you make it as airtight etc. as the rest of your windows)?

Aye piss easy for the joiners. I would say 10mm will ne fine thats what we jad, do they state more? 

 

Airtightness was so far just expanding foam to fit them as they sit inside the kit panel just. I'll tape them later when doing the membrane inside with tescon vana airtightness tape. Bit no compribamd or that. 

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1 minute ago, SuperJohnG said:

Aye piss easy for the joiners. I would say 10mm will ne fine thats what we jad, do they state more? 

 

Airtightness was so far just expanding foam to fit them as they sit inside the kit panel just. I'll tape them later when doing the membrane inside with tescon vana airtightness tape. Bit no compribamd or that. 

They say 40-60mm across the width and 45mm top to bottom. I'll just go with the 10mm either side then, cheers.

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