How to fix cracks around UPVC windows

[username132]

About seven or eight years ago my mother's house was renovated and the windows were changed. The single downstairs window was changed into two smaller windows with some bricks in between. My mother says that she has noticed the curtains moving when it's windy outside and I see cracks all the way around the window which appears to be a conduit for air. How should I try to seal these cracks in a reasonably attractive (or at least not wholly unattractive) way? Thanks!

 

[foxhole]

colour matched sealant all round, probably need the outside doing as well if you get draught thru it.

 

[username132]

colour matched sealant all round, probably need the outside doing as well if you get draught thru it.

Thanks! Is that silicone sealant? Are there different kinds or can you use the same one inside and outside?

 

[foxhole]

http://www.screwfix.com/p/sika-sikaflex-ebt-all-weather-sealant-white-300ml/87344?kpid=87344&cm_mmc=Google-_-Product Listing Ads-_-Sales Tracking-_-sales tracking url&gclid=CLfWzvDPiNECFVAQ0wodNLkEjg

Inside and out.

 

[username132]

Thanks!

 

[Gazman16]

I would use caulk inside (preferably Wurth acrylic sealant) Masking tape straight edges around the window, Pump in as much caulk as you can, Run your finger over it both ways a couple of times, Paint it and then remove the tape. = Straight neat edges.

Silicone will get mucky and discolor over time.

 

[username132]

I'm in the process of removing the old sealant outside the house. In most places, the sealant looked like it had shrunk and the layer that was attached to the uPVC was extremely thin. Is it possible that the sealant was not rated for outdoor use and shrank in the rain? Almost the whole way around, the thin strip of sealant on the uPVC was separated from that attached to the brickwork.

I've removed what I can with a scraper but I couldn't get it all off. I have bought a silicone caulk remover but I'm not sure whether the original stuff is silicone or acrylic or something else. Is there some way to tell? In this case, it's white.

 

[ronniecabers]

I would say you are looking at the silicone moving as the other materials shrink/expand in varying weather conditions. Its unlikely to be a decorators caulk as that doesn't like the weather at all and wouldn't have lasted nearly as long. Getting it off has always been tricky, remove as much as you can , then use a rag to create friction to remove most stubborn areas ...or even a single edged razor blade ( but don't dig into the pvc! )

 

[Doggit]

That's way too much gap outside for sealant, and possibly inside as well. I can't cut and paste on this computer, so look for 12mm upvc quadrant beading, then use silicone sealant between the beading and the wall.

 

[username132]

The gap varies quite a bit and reaches a maximum of 8 mm. Is this definitely too large for only sealant? To install beading am I meant to put sealant between the beading and the wall and again between the beading and the window frame. Should I tape the beading into place while the sealant dries? Thanks!

 

[Doggit]

You stick the beading to the window using superglue, and then spray the joint between the beading and the window with activator. The really good installers put superglue on the beading, spray the window with the activator, and then put the two together, but I haven't mastered that trick yet. Then you'll silicone the joint between the beading, and the wall. If the maximum gap is 8mm, then you may want to go for a 20mm beading instead.