Draughty windows

mikefromcork

I can feel a draught from almost all the windows in my house. There are gaps of up to 10 mm between window and interior sill. I thought about filling these gaps but they are around 25 mm deep so I'm not sure if there is any point. Any advice is appreciated.

I have a photo but can't figure out how to add it.

MicktheMan

Not unusual.
What's the make-up of the wall do you know?
Filling such gaps with sealant, if done well, will last a few years but will need to be redone over and over.
Longterm, removal of window board and doing a proper job with airtight tape, mastic & membrane is the only way to permanently address this.

mikefromcork

MicktheMan wrote: »

Not unusual.
What's the make-up of the wall do you know?
Filling such gaps with sealant, if done well, will last a few years but will need to be redone over and over.
Longterm, removal of window board and doing a proper job with airtight tape, mastic & membrane is the only way to permanently address this.

Left and right are rock solid so presumably plastered blocks. Top feels like plasterboard.

i57dwun4yb1pt8

i had this problem gaps about 4 to 5 mil wide and about 15 deep between sil and window frame in all frames ,
filled them all with clear tech 7 . house instantly warmed up .

mikefromcork

Enoch Worried Bat wrote: »

i had this problem gaps about 4 to 5 mil wide and about 15 deep between sil and window frame in all frames ,
filled them all with clear tech 7 . house instantly warmed up .

This one? https://tec7.ie/product/trans7-clear-sealant/

i57dwun4yb1pt8

yes thats it , its stays a little flexible so doesnt shrink, so far so good after 3 years .
expensive enough , i needed two tubes approx 30 euro the lot

possibly fil the holes with normal crack filler first to bring the level up , then top of to seal with this stuff.

carefull if you think it will stand out too much cos its not great to take paint ,
if not find a slicone sealer that suits the color you need.

it made a huge difference to my heating and bills , there was some amount of leakage / cold air ingress before this , mainly cos the the place i bought has 2 gigantic 3.5 meter by 2 meter windows in one room

mikefromcork

I will go with sealing for now and the permanent solution at a later date. Thanks to both of you, much appreciated.

mikefromcork

So I went with the sealant and have someone lined up to do the membrane later in the year. The draughts from those gaps is much improved. My problem now is that with the easterly winds the house is still very cold. Looking at the windows from outside there appear to be gaps around all 4 sides of the windows and under the sill. Can I seal those? If so, anyone able to advise me on what to use? Thanks.