Flat roof window on a flat roof - what angle?

[pikey]

I have three newly fitted flat roof windows on my flat roof.

The roof is at an angle where the water neatly runs off, but the windows appear to be near flat so any rain water stays on them. Whilst they are 100% weatherproof (at the moment), I don't think they're quite right, particularly as the general muck in rainwater leaves rings as it dries.

The builder tells me they're fitted properly and I can't find any reference to indicate this isn't so. Can anyone point me in the right direction?

The windows are bespoke (strange sized) so there's no central manufacturer to read instructions from.

Thanks

[SS HSV]

That's going to be a real pane to clean.

[Flintstone]

SS HSV said:

That's going to be a real pane to clean.

Clearly.

[bimsb6]

rainex them

[elster]

So you have flat windows on a flat roof, and you are questioning why the rain isn't running off.

Isn't this one obvious?

[Sgt Bilko]

(if Velux-type windows) they should be fitted with a min 20deg slope, perhaps down to 15deg if not much rain. Definitely not flat. If flat, roof domes would be better.

See here: http://www.velux.co.uk/Products/Flat_roof_system/T...

and/or this http://www.velux.co.uk/Products/Flat_roof_system/I...

Edited by Sgt Bilko on Tuesday 14th October 21:15

Edited by Sgt Bilko on Tuesday 14th October 21:17

[Autonotiv]

Hard to say without seeing it, are they dead flat? if so seems a little odd.

[Big Al.]

The normal is usually between 5 and 15 degrees on a flat roof IIRC.

[pikey]

I think the roof is about 5 degrees and the window about 1 degree.

In my layman's opinion if the window was also 5 degrees there'd be no stagnation.

[Sgt Bilko]

pikey said:

I think the roof is about 5 degrees and the window about 1 degree.

In my layman's opinion if the window was also 5 degrees there'd be no stagnation.

Definitely dodgy mate. Nip over to here to check

http://www.diynot.com/forums/

[mybrainhurts]

pikey said:

I have three newly fitted flat roof windows on my flat roof... The roof is at an angle where the water neatly runs off, but the windows appear to be near flat so any rain water stays on them.

Can't you just park the caravan on a hill...?

[SS HSV]

Oi dont upset the dawgs

[groucho]

pikey said:

I think the roof is about 5 degrees and the window about 1 degree.

In my layman's opinion if the window was also 5 degrees there'd be no stagnation.

Why is the window less than the roof? They need a slope.

[pikey]

groucho said:

pikey said:

I think the roof is about 5 degrees and the window about 1 degree.

In my layman's opinion if the window was also 5 degrees there'd be no stagnation.

Why is the window less than the roof? They need a slope.

That's my question!

[trumpet600]

If the flat roof runs to a fall (you mention 5 degrees) then surely it's obvious the the window should be fixed to an upstand that is parallel to the roof

[911motorsport]

pikey said:

groucho said:

pikey said:

I think the roof is about 5 degrees and the window about 1 degree.

In my layman's opinion if the window was also 5 degrees there'd be no stagnation.

Why is the window less than the roof? They need a slope.

That's my question!

They have been fitted back to front! Some Velux type windows incorporate a 5 degree pitch in the frame so as to exagerate the pitch of the roof they are fitted in to, and thereby shed rain water quite easily.

Edited by 911motorsport on Wednesday 15th October 09:04

[pikey]

these are custom made. Builder constructed an opening and glazier made window to go on top.

I don't mind custom made over something like a Velux but because the specifics of the roof window isn't on the architect's drawing it's unclear whether it should be angled or not (and I have asked him, he didn't know. Said to ask the builder!).

[pikey]

Pic:

[tvrtim]

These will give you grief. If they are double glazed the units will soon fail due to no means of drainage. As previously stated you should have used Domes.

[thehawk]

Could you fit a set of wipers?