Sealing draughty uPVC windows - Tesamoll fits the bill (gap)

The next best thing to new windows

A uPVC window repairer (‘no job too small’) swapped out the hinges on our upstairs uPVC windows for ‘fire escape’ ones just like we requested. Trouble is, some of them didn’t fit too well afterwards and the seal isn’t that good. We’re left with draughts in some places and stormforce rainwater sometimes gets driven through the gap. The fitter blamed the seals ‘drying out and shrinking’ just before he rode out of town on his horse.

Various replacement uPVC window seals are sold online or on ebay, all made of black rubber but there are many different profiles and sizes, so matching and swapping the right uPVC window seals looks to be an onerous and very time-consuming job. There’s also no guarantee that new seals would be much better than the old ones.

Tesamoll is supplied in triple extrusions. Split them apart to use.As the next best thing, I decided to tackle my draughty windows with good old draught excluder – but I needed a high quality weatherproof one that will last for years, preferably in white which won’t stand out like black rubber does. It needed to fill a gap starting at 2mm or so.

After much searching around the answer came in the form of German-made Tesamoll weatherproof draught excluder. The ‘Large’ size suits gaps of 2-5mm and it’s claimed to last 8 years. The shapes are described as D, E, I or P-profile, depending on the cross section. I could have used ‘D’ profile but P-profile was available and seemed just the ticket. It’s made in white or brown rubber, and is also weatherproof, UV and ozone resistant so you know it will last.

Tesa specialises in making adhesives and is a well-known manufacturer in industry and consumer goods. Their P-profile tape comes in lengths of three extrusions side by side, to make 10 metres in total (6m and 25m rolls may also be available.) Simply tear off one strip as needed, and I found they easily stuck along the edges of windows and would meet the existing black seals to form an excellent seal. As the windows are closed far longer than they’re open, sticking draught excluder on the window frame this way wasn’t a problem as the ‘open’ appearance did not really matter much, and the white stick-on rubber seal would look OK when viewed indoors; nor would the repair show from outside.

Tesamoll P-Profile, Rubbing Alcohol and lint-free cloths are neededPreparation is key to success, so for maximum adhesion the windows and seals must be clean and grease-free. It’s best to wipe them down with some eg Rubbing Alcohol (Isopropanol and 30% distilled water) on a lint free cloth. Then try a small piece of draught excluder to judge how it ‘mates’ with the existing window seal once the window is closed.  The aim is to get a good fit between the two surfaces and fill any gaps.

Then simply apply the excluder along the edges, peeling away the backing paper as you go. Don’t press it down hard until it’s in place and you’re happy with it. You can lift and re-position it so it doesn’t squash out too much when closed. Then firm it down with the palm of your hand. It will stick better in warmer weather.

Tesamoll sticks strongly to clean uPVC windowframesAfterwards I found that the windows closed easily and the seal was now perfect, rainproof and draughtproof too. Being white, it is also barely noticeable.  Tesamoll has given these windows a new lease of life at next to no cost. Note that the adhesive will get stronger as time goes by, and the profile will squash down as a matter of course. 

The white seal is barely visible indoorsTesamoll weatherproof draught excluder is available on Amazon in white and brown. You can learn more about their products on Tesa’s web site.  Rubbing Alcohol is cheap and readily available online and is a useful general purpose solvent cleaner and also a medical aid.

You can purchase various Tesamoll P-profile draught excluders direct from Amazon via these links:

White - 6 m x 9 mm x 5.5 mm - https://amzn.to/3VikXJT

White - 25 m x 9 mm x 5.5 mm - https://amzn.to/3VledLe

White - 10 m x 9 mm x 5.5 mm -  https://amzn.to/3PtZhH4

Brown - 25 m x 9 mm x 5.5 mm - https://amzn.to/3x0li9U

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