How to finish cladding around window

18 Nov 2005
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United Kingdom
I have successfully fitted a replacement dormer window
I have also clad the sides to match the window
But am having a problem trying to sort out the trim from the window over the wooden frame to meet the side cladding

I have used hollow sofit boards and edge trim to clad the sides now on the front I have the plastic window and timber frame to plastic over the problem being the bottom of the dormer on the sides with the cladding fans out so it is not straight the gap at the top is around 80mm but fans out at the bottom to about 120mm so a straight piece of plastic trim will look stupid

The dormer itself was constructed that way for whatever reason so it leaves me with a problem of trimming the front to catch the sides and make it water right

Any ideas?
If I can get onto the lappy I will sketch I diagram to illustrate what I mean better

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added image to illustrate what i mean

as you can see the side of the dormer is feathered out at the bottom
i need to trim from the window frame across the timber to make it water tight but because it is feathered out at the bottom i cant figure out the best way to do it

my suggestion would be make up an "L" shape trim around 10mm bigger than the cladding thickness so 12mm cladding +10mm will be 22mm internal and assuming you have a 10mm wall this would be 32 x 32mm section
or if the cladding is butting up rather than at right angles then a "T" section with again a10mm overlap so the top off the "T" will be 10mm/10mm/10mm so 30mm x[10mm/10mm] 20mm
you could run it out from 2x1"[21x44mm] and just adjust the size accordingly
thanks for the reply big all

im not sure i understand/follow what you mean though.

i dont suppose you could break it down to idiot proof could you please

i sort of caught your drift in the begining but then lost the plot i think

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you need to avoid wood butting up together so you need something that will overlap both the frame and the cladding sufficiently to allow for both expansion and contraction and cover the end grain

basically i missed your drawing but if you draw a line around 10-15mm in from the side off the frame then the same round the corner covering the cladding this is the size you "L" shaped molding should be to keep the weather out

if your cladding is plastic then you could use facia board as they are a "L" shape and around 9mm thick

still confused please ask again :D :D ;)
Thanks again for taking the time to reply

The cladding is plastic and I used the hollow soffit board

I get what you mean about using facia board as the trim

The only bit I don't understand is to allow for where the cladding kicks out at the bottom

You don't mean to cut the trim to follow the cladding do you?

Sorry for being a pain
I'm sure it is simple I just need to get my head round it

If there was just say for example 10mm gap evenly all the way down a L shape trim would fit and job done

I just can't get my head around allowing for the feathering out at the bottom
how much does it actually kick out where it feathers ?? i assume about 20mm

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