I've just had new double glazed units installed as part of an extension build. There is a noticeable draught at the base of the windows, and the internal windowsill is very cold. Looking at the outside, I can see a clear gap between the upstand on the sill, and the base of the window unit (in fact you can actually see light from the room coming through small gaps around the internal windowsill if you look into the gap from outside). It appears that cold air is just blowing straight through here and into the house. I have attached a photo, below, which I hope shows the problem.
I discussed this with the builder, who advised me that the work is not finished, and he will be adding sealant to fill the gap. I want to make sure this is fitted correctly, so can someone advise what the correct installation method is for a double glazed unit like this? Am I correct to assume that the unit should butt up against the sill, rather than having such a large gap? Is it correct to just be filling the gap with sealant? The double glazing manufacturer has not been very helpful with installation advice, and says it is up to the builder!
Thanks in advance for any advice.
I discussed this with the builder, who advised me that the work is not finished, and he will be adding sealant to fill the gap. I want to make sure this is fitted correctly, so can someone advise what the correct installation method is for a double glazed unit like this? Am I correct to assume that the unit should butt up against the sill, rather than having such a large gap? Is it correct to just be filling the gap with sealant? The double glazing manufacturer has not been very helpful with installation advice, and says it is up to the builder!
Thanks in advance for any advice.