On 21 June, 12:55, "David WE Roberts"
wrote:
"David WE Roberts" wrote in ...



I set off to fit the window cill to the frame and became unsure of the
correct fitting.

Pictures a
http://i817.photobucket.com/albums/z.../Mother%20of%2...
http://i817.photobucket.com/albums/z.../Mother%20of%2...
http://i817.photobucket.com/albums/z.../Mother%20of%2...

As far as I can see there should be a gap at the front for concealed
drainage - so that looks O.K.
However there is a gap at the back of the cill where the ridge on the
window does not quite fit into the groove on the cill.
This means that if fitted together as shown in the third picture all
contact between the window frame and the cill is resting on the two
central ridges which is not a particularly stable arrangement.

I was expecting the cill and frame to fit together snugly in an obvious
way but this is the best that I can achieve.
If the cill had been flat all the way to the back ridge then it would have
fitted much more securely and also had much less chance of moving out of a
90 degree angle between the cill and the frame.

Swift and helpful response from Duraflex:

"I have attached a cross section of the casement window positioned on a
150mm cill, the centre legs are the "support " legs, the front has to slope
away on the cill to facilitate the concealed drainage path. The back leg
would be bedded on a continuous bead of silicone to provide a weather tight
seal.

I have not shown the screw position because fitters will either screw from
the bottom directly into the frame or from the top behind the bead channel
before glazing, if the later method is used then silicone should be applied
to the pre drilled hole before the screw is inserted.
"

Or you fix the sill to the opening first, using frame fixings and
pack / level up.
Silicone to seal the fixings. Then self-tappers though the window
frame into the sill, but not all the way through to the brick. I've
found this to be the best solution.
Simon.