Velux below minimum pitch

Discussion in 'Builders' Talk' started by Sam Dingle, Dec 1, 2004.

  1. Sam Dingle

    Sam Dingle New Member

    Hi,
    I want to install a Velux M06 in a roof that has a pitch of 11 degrees.
    The window is spec'd at 15 degrees.
    Has anyone ever done this or has any advice as to what to do?
    I could build up a kerb to increase the slope but flashing becomes tricky.
    I'm an engineer and when we design stuff we make it so that it can cope with the worst case and still have some headroom. The window is going to be install in Hampshire (not near the coast or in a exposed position). I imagine Velux have designed thair windows so that they could be used in the shetland isles etc..
    Anyone think I can get away with installing it at 11 degrees? (I know it would invalidate any guarentee.
  2. TwoSheds

    TwoSheds New Member

    Sam, I'm no expert but when I fitted a Velux (a bit bigger than M06) to my 15 deg tiled roof my feeling was that this was the limit, in fact I would have liked to have had a greater pitch - some of the flashing was almost horizontal. It may depend on the profile of the particular tiles used. Have you considered the Velux FRS?
  3. Sam Dingle

    Sam Dingle New Member

    Yeah, I looked at the FRS but could couldn't see if the kerb was trimable or not.
    Does anyone know if the FRS is just a standard M06 bit with a pre fab kerb and dedicated flashing kit?
  4. bris

    bris New Member

    i'm looking at a picture of frs it's up to 15 deg it shows flat roofing felt but i could'nt see any problems with lead
    flashing over tiles
  5. jenros

    jenros New Member

    hi sam, a couple i have been doing renovations for off and on for a few years had a poor quality roof light installed every few years they had to have it repaired (botched),being told that the seals had broken down,etc,one excuse after another,the top of the range botcher advised them to silicon it closed,so they agreed .this went on for a few years,every year or so they would come and reseal the window,saying that the silicon was breaking down to the cold weather etc. when they asked me to have alook at it,about five minutes problem found,the pitch was to shallow,they to had built up the rear of the window to try to compensate for this,the problem being in the autumn the leaves were gathering behind the window,getting wet,and lodging around the tiles etc,then when it rained heavy the leaves was causing a dam at the rear ,the water would then back flow up under the felt,hence the water leaks inside the house.to solve this i ripped the lot off,green mineral roor with osb decking,its been fine for two winters,you could also form a roof light in timber and use some polycarb sheets and some self supportingbars (same as used in conservatories). hope this has helped!!!!!!!!!!!!!!!!!!!
  6. Sam Dingle

    Sam Dingle New Member

    Hi Jenros,

    Thanks for that.
    I'm already installing ondutile sheeting underneath the slates to act as a secondary layer so that should get around the backing up problem.
    I'll see how I get on.

    I've tried to find some diagrams on how to do all this but could only find a little bit on the onduline website.

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