12-13 degree tiled roof with Velux flat roof windows

[desig]

Hi all,
I queried this with Velux, and they said it would be fine. However, I'm just wondering if anyone has any example pictures of this type of work done before.
I tried looking online and couldn't find anything for this sort of scenario.

We are going to start our new rear extension at the end of the month.
The work will be done by a local builder, who is recommended by other people who have used him.

The extension will have a 12-13 degree pitch roof, which will have roof tiles - tiles chosen are Monier Regent, which we know are suitable for low pitch roofs.

We also want to have rooflights. Two of them will be over the kitchen and don't need to open, however we would like one of them (which will be over the utility room) to be openable.
Building control have approved the plans, so we are ok from that side to start work.

I had a look at the following Velux flat roof windows, and they seem like they will be suitable to use in a low pitch scenario, though they don't necessarily mention using them on a tiled roof.
VELUX CFP 090120 S00M
VELUX CFP 100150 S00M
VELUX CVP 090090 S06Q
VELUX CVP 100100 S06Q

I asked Velux if they would be suitable in a 12-13 degree pitch roof with roof tiles, and they say it would be.
Has anyone done this/seen this before? do you have any pictures you can share of how it would look when complete?
Are there any things i need to be mindful of? I'm guessing we would need to be careful to make sure water can pass around/under it without penetrating the roof.

Image i sent to Velux:

View media item 97333

Thanks in advance

 

[freddiemercurystwin]

Hmm, those windows are all as ugly as sin and personally I would not want them in my extension from an aesthetic viewpoint both from inside and out.

Anyway as they are really a fat roof window you would normally dress your roof membrane eg felt or grp up the rooflight upstand or use a preformed flashing in a metal roof.

However on a pitched roof you would just have a roof underlay so I’m not sure how you’d go about waterproofing them. I guess you could bond a grp or similar finish to them but that would need a board like plywood immediately under the battens to bond to and then the roof underlay would lap over that. But then how could you nail the ends of the battens down through the membrane. All a bit messy to say the least. I would be asking Velux how they would propose waterproofing it if they are saying it’s so easy. Maybe a lead flashing made up by a good leadworker is the way to go – that could tuck under the roof underlay.

That said personally I would be using an alternative from say Fakro who also supply a special flashing kit http://www.fakro.co.uk/products/all...ecial/for-changing-window-installation-angle/ to enable a conventional rooflight to be fitted in a low pitch roof though you would have to check they were compatible with your tiles. There may be other suppliers offering similar products though I know Velux don’t.

Get a roof window installation wrong and it will leak forever.

 

[DIYedboy]

If I was you I would look at Forticrete low pitch roof windows, they can go down to 10 degrees I think

 

[desig]

Thanks for the details.
It certainly looks like the Fakro kit is just what we need.
The Monier Regent tiles have a profile of 63mm, so I would be right in saying that we would need the "EHA" flashing kit? (supports tiles up to 90mm profile, while the EZA kit only covers to 45mm)

I take it that would also mean purchasing Fakro windows instead?
Fakro seem to do the same dimensions as the Velux windows I was originally looking at before I saw the flat roof windows, so that should be ok.
Found this, which would be the size we would use for the kitchen windows: http://www.sterlingbuild.co.uk/prod...iple-glazed-centre-pivot-roof-window-134x98cm

 

[desig]

If I was you I would look at Forticrete low pitch roof windows, they can go down to 10 degrees I think

Thanks for the suggestion. Admittedly I've only done a quick search from work, but it seems Forticrete is more about the system (and using their tiles), rather than the window specifically?

 

[freddiemercurystwin]

The Forticrete system uses a Fakro window I believe.

Yes you need to use a Fakro window with the Fakro flashing kit. But I would ring them and check the flashing/rooflight/tile compatibility to make sure you get the right combination.

 

[jontop]

Hi desig, this might not help and probably too late but, is it possible to raise the pitch of the roof? This will eliminate your immediate problem and make sure you don't have future ones!

 

[desig]

Hi jontop
A timely response, as the building work starts next week! (got delayed by a few weeks).
Unfortunately, i don't think it's possible to raise the pitch of the roof. The house has already been extended to the side, and the window on the side extension part is larger than the original house so comes a bit lower. I think the pitch is the best it can be, or could only be raised by another 0.5 degree max.

However, after freddymercurytwin's advice, I looked into Fakro windows and contacted them.
Fakro confirmed that their low pitch kit would work with the Monier Regent tiles on a 12-13 degree pitch. So this is what I am looking to get:

Fakro Flashing kit to raise angle: EHA-P (http://www.fakro.co.uk/products/all...ecial/for-changing-window-installation-angle/)
2x FAKRO EHA 12 low pitch deep tile flashing 134x98cm
1x FAKRO EHA 03 low pitch deep tile flashing 66x98cm

Windows:
Fakro Centre Pivot Window with U5 triple glazed pane
2x FAKRO FTP-V U5 12 pine triple glazed centre pivot roof window 134x98cm
1x FAKRO FTP-V U503 pine triple glazed centre pivot roof window 66x98cm

 

[hardmetalking]

Not too late to change your
Mind....

 

[freddiemercurystwin]

Sweet! Do you ever work in Devon hardmetalking ?

 

[hardmetalking]

I work everywhere!

 

[freddiemercurystwin]

I'll bear that in mind!