window sill extensions external insulation

[hunggaur]

hi folks i hope some one can help as i am banging my head against the wall on this one.

we are buying a bungalow that we want to extend, part of the process will be to re insulate the house on the outside by applying 100mm external insulation then rendering the whole house.

one of the problems i see is that the current windows the sill will be to short to allow water to clear the insulation so they will nee extending.

the windows are all new upvc and to complicate matter even more one of them in a bay

ideas and options welcomed.

cheers

jon

 

[Mw Roofline]

The only way is to move all the windows outwards and create bigger internal reveals/cills. You may have to create a strong fixing frame 1st.

 

[hunggaur]

hi thanks for coming back to me

it is physically impossible to move the windows forwards as there would be nothing to fix into adding 100 to 150 mm insulation means the windows would then have to fix into the insulation and would not be secure.

i have read a lot about this and you can get extensions for your original sill just trying to find out where from have found one place in Ireland but is £50.00 a meter. looking for cheaper options.

cheers anyway

jon

 

[Mw Roofline]

hi thanks for coming back to me

it is physically impossible to move the windows forwards as there would be nothing to fix into adding 100 to 150 mm insulation means the windows would then have to fix into the insulation and would not be secure.

i have read a lot about this and you can get extensions for your original sill just trying to find out where from have found one place in Ireland but is £50.00 a meter. looking for cheaper options.

cheers anyway

jon

Was the place in Ireland called Freefoam?

 

[^woody^]

You should be able to design a a new cill/drip feature below the cill with tiles or lead.

 

[hunggaur]

You should be able to design a a new cill/drip feature below the cill with tiles or lead.

no it was these people http://www.externalinsulation.ie/profiles.php nice idea about the tiles may look into that a little more. also thought about speaking to my local window man to see if he could make something for me.

cheers jon

 

[crank39]

How about using a standard 180mm cill and ripping a portion off the back of it and placing it under the overhang on your existing cill, the over hang of the existing cill would/should cover the flat part (where the window sits on top of) of the new cill, a bead of silicone between them and screwing upwards should hold them together

 

[hunggaur]

How about using a standard 180mm cill and ripping a portion off the back of it and place it under your existing cill, the over hang of the existing cill would/should cover the flat part (where the window sits on top of) of the new cill, a bead of silicone between them and screwing upwards should hold them together

sorry being a little thick not sure what you mean. if i place it under the current sill wont i end up with a double step at the front. current cill drip edge+ the new sill drip edge???

would it be better to consider placing something like a facia board on top of the sill ?????

if you have a sketch of what you mean that would be great.

cheers

jon

 

[freddiemercurystwin]

Just get some powdercoated aluminium ones made up and stick 'em to the existing like this: http://www.truelineproducts.co.uk/over-sills.htm

 

[crank39]

How about using a standard 180mm cill and ripping a portion off the back of it and place it under your existing cill, the over hang of the existing cill would/should cover the flat part (where the window sits on top of) of the new cill, a bead of silicone between them and screwing upwards should hold them together

sorry being a little thick not sure what you mean. if i place it under the current sill wont i end up with a double step at the front. current cill drip edge+ the new sill drip edge???

would it be better to consider placing something like a facia board on top of the sill ?????

if you have a sketch of what you mean that would be great.

cheers

jon

Yes you would have a double step, could you live with it.......hmmm i think i could.

As for the facsia board, if only life were that simple , this solution would most certainly cover the concealed drainage between the cill and window (assuming it is concealed drainage and not face drained), do this at your perril, do not obstruct the drainage

 

[crank39]

Just get some powdercoated aluminium ones made up and stick 'em to the existing like this: http://www.truelineproducts.co.uk/over-sills.htm[/QUOTE]

Top link, well done that man

 

[Zebra579]

hi thanks for coming back to me

it is physically impossible to move the windows forwards as there would be nothing to fix into adding 100 to 150 mm insulation means the windows would then have to fix into the insulation and would not be secure.

My understanding is that if you were either building from scratch or having new windows made, you build a ply box which extends out into the insulation, so that the window sits out in the insulation, but its weight is held by the ply, which is fixed into the wall.

I understand this may not work if you are using the same window in the same hole, just thought I'd mention it in case.

 

[oystercacher]

hunggaur,

I wonder if you could tell me which solution you went for in the end please? and are you happy with it? We are doing the same job shortly.

Its my preference to modify the existing sills with something like the trueline aluminium sill extension since I think that'll look best, and it seems to be a standard solution, but my wife is keener to leave the existing sills alone and add something below the existing sills to shed water.

Thanks