Leaking uPVC window

Discussion in 'Builders' Talk' started by spider06, Feb 1, 2008.

  1. spider06

    spider06 New Member

    The double glazed window on the first floor of the gable end of my house leaks on the inside if the rain is blowing from the right direction.

    The water comes in from the join of the top of the window frame and the underside of the reveal where the lintel is.

    I have applied loads of mastic outside around the frame. which has made no difference. The bricks and pointing of the wall are in good condition i.e. no cracks, holes or the like.

    Can anyone suggest a way to cure this please.

    Thanks for suggestions in advance.
  2. Doink

    Doink New Member

    Is there a lintel (catnic or concrete) or just plain bricks sitting on the frame?
  3. spider06

    spider06 New Member

    Hi,

    Its plain bricks on the frame.

    Cavity wall construction.
  4. kaintheo

    kaintheo New Member

    You said you have no lintel but the original post said you did have a lintel.

    In any case it could be a lack of a cavity tray causing this problem, hence whay the mastic is having no effect.
  5. spider06

    spider06 New Member

    Thanks for the replies.

    Sorry that I'm being a bit unclear but I'm not 100% sure about the construction around the window.
    I'm pretty sure there is a concrete lintel on the inner wall, but the outer wall is just brick work. The house was built in the early 70s if that helps.

    If I were to install a cavity tray would it go in on the second course of bricks above the window?

    Thanks.
  6. kaintheo

    kaintheo New Member

    A cavity tray will come down to the lintel with weep vents installed to dischardge any water to the outside.

    Is the brickwork on the outside at a slight arch or a soldier course?
  7. Doink

    Doink New Member

    Right,im not saying this is your problem but its one i've come across in 15 years of fitting windows.

    Is there a piece of trim siliconed to the underside of the bricks that are sitting on the window? If there isnt then without looking its difficult but if there is does the front edge of the trim stick out further than the bricks,forming a ledge,sometimes thw window is short in height allowing a trim to be slid in making the sealing up easier,IF this is the case virtually certain that water is running down the bricks sitting on this ledge(if its there) silicone seal on top is worn out,water is running along this trim to the back which by this time is on top of the frame,water sits in between the ribs on the frame head and either runs to the sides OR fills up enough to pour in in between the frame and plaster.

    Again,if you have no trim above then this is unlikely.

    Good luck
  8. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    It's possible that some mortar joints are failing further up,or even the water is running over the edge of the roof, along the undercloak, up and under the topmost bricks, and into the cavity. Then running down inside the cavity and out at the top of your window.

    Builder/roofer needs to have a butchers.



    Mr. Handyandy - really
  9. kaintheo

    kaintheo New Member

    Thats right, it could be that and thats why a cavity tray is needed if you don't already have one.

    The window trim idea is a sound possibility also as I,ve seen this happen once or twice before myself.
  10. sammy toaster

    sammy toaster New Member

    "undercloak" handy andy has been reading his "spons" guide again.
  11. J.T. Builders Ltd

    J.T. Builders Ltd New Member

    Handyandy, tut tut tut

    It's possible that some mortar joints are failing
    further up,or even the water is running over the edge
    of the roof, along the undercloak, up and under the
    topmost bricks, and into the cavity. Then running
    down inside the cavity and out at the top of your
    window.

    Builder/roofer needs to have a butchers.



    Mr. Handyandy - really

    water does not run up hill!

    I would say it needs a cavity tray if all the external brickwork is getting a very good soaking.

    i would advise you to get a local builder in, he can also have a look may be something else that will be obvious to a trade but not to a DIYer.
  12. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Handyandy, tut tut tut

    It's possible that some mortar joints are failing
    further up,or even the water is running over the
    edge
    of the roof, along the undercloak, up and
    under the
    topmost bricks, and into the cavity. Then running
    down inside the cavity and out at the top of your
    window.

    Builder/roofer needs to have a butchers.



    Mr. Handyandy - really

    water does not run up hill!

    I would say it needs a cavity tray if all the
    external brickwork is getting a very good soaking.

    i would advise you to get a local builder in, he can
    also have a look may be something else that will be
    obvious to a trade but not to a DIYer.




    Sorry to disappoint, but water can indeed run uphill.

    Ever syphoned water ? Or petrol ?

    Or seen water run off the bottom edge of tiles, and pour up and backwards ?

    It certainly CAN run upwards.

    However, in this case I am referring to the water running from edge of tiles, over the mortar filling, running BACK under the undercloaking to the brickwork and OVER the top of the bricks, into the cavity.

    Hence 'up and over the bricks'.

    Hope that clears it up.



    Mr. Handyandy - really
  13. sammy toaster

    sammy toaster New Member

    fraid not andy, it don,t make it any clearer, are you talking wind driven rain or capillary attraction?
  14. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    fraid not andy, it don,t make it any clearer, are you
    talking wind driven rain or capillary attraction?




    neither of those.

    The undercloak is essentially 'level', from the outside edge to brickwork directional perspective.


    Therefore the water can run along it under it, straight to the top of the brickwork(and over and above the brickwork.

    Same reason why a windowsill has a 'drip' or groove cut on the under-side/outer edge.

    But the undercloak is flat.


    The top of the fascia/barge-board should be sealed against the undercloak(might even be upturned tiles) to stop this water running back.



    Mr. Handyandy - really
  15. spider06

    spider06 New Member

    Thanks for the replies everyone much appreciated.

    Sorry I haven't answered sooner, been away from my PC.

    1doink, I checked on your suggestion and luckily there isn't anything like that. The window goes straight up to the bricks. Looks like a good proper fit.

    Kaintheo, I looked and there is neither an arch or soldiers.

    I think my best bet will do as a couple of you suggested and get a builder/roofer in.

    As you said I am just a DIY'er and my experience certainly doesn't lie in this area. I could end up putting a cavity tray in, stopping this small problem and leaving something a little more sinister undone.

    Thanks for the advice everyone every helpful as always.

    Cheers.
  16. sammy toaster

    sammy toaster New Member

    "directional perspective" andy you have excelled yourself. go on tell us ,where did you get that from?must have been from a building college booksale.
  17. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    "directional perspective" andy you have excelled
    yourself. go on tell us ,where did you get that
    from?must have been from a building college booksale.




    It was just the first words that came to mind. I did wonder about the validity of the phrase myself, but I was convinced that to explain it in any other way would have taken a great many more words. :)


    Mr. Handyandy - really

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