Sealant for PVC window frames (external)?

paperclap

Hi all,

First and foremost, happy Easter! 

I’ll keep this short and sweet. Externally, I’m taking off all the sealant around my window frames, where it meets the brick. Coming away in a lot of places, and in two areas, has resulted in minor water ingress.

Been looking around, and weirdly struggling to find the right product. It needs to be low modulus, neutral curing, UV resistant. Preferably clear too. Think it gives a better finish and sharper line. Plus, find white is hard to get a good finish on, with brickwork - I’m no pro 

No acetoxy, as it’ll eat the uPVC frames.

A lot of “external frame” and “glazing” sealants tick the above criteria. But what is the difference between the two products?

Has my eyes on Dow 796 and Dow 799. A few quid more expensive than the “cheaper” No Nonsense stuff, but people seem to rate it, it’s 100% silicone, etc… all that good stuff.

https://www.screwfix.com/p/dow-796-upvc-silicone-sealant-brilliant-white-310ml/40004?ref=SFAppShare
But only comes in white! Can’t find it anywhere in clear.

https://www.screwfix.com/p/dow-799-glazing-silicone-clear-310ml/66307?ref=SFAppShare

Not sure if this is right? Seems like the stuff to seal behind skylights, etc?

Thanks!

grumbler

paperclap said:

Preferably clear too. Think it gives a better finish and sharper line. Plus, find white is hard to get a good finish on, with brickwork - I’m no pro 

Any cavity/gap filled with clear silicone will look almost black. Is this what you really want?

My personal choice would be grey  silicone, e.g.

Grey matches mortar. You can match bricks, e.g. with brown.

mi-key

Are the windows white ? It is normal to match the sealant to the frame colour as this gives a better finished look. using another colour will never match the brickwork properly and be more obvious

paperclap

The frames are white, yeah.

We’ve currently got white sealant on the house frames. Then on the conservatory, we’ve got clear.

Don’t you think the clear looks far better?

grumbler

Yes, clear is better, but because it fills mainly the corner, not the gap.

IMO, a better way of doing this is when when silicon fills the gap and is slightly recessed against the frame front serface, 0.5-1mm. Builders don't like doing this as it's more neat job taking more time.

There is clear builders silicone in the same range at SF. Not sure about low modulus.

https://www.screwfix.com/c/sealants-adhesives/brick-sealants/cat850068

plumb1_2

Just use a sanitary sealant 

paperclap

Why a sanitary sealant?

greenface2

Pop into euroell and ask advice . I use eurocell silversil LMN . LOW Modulaus Neautral . Antifugisidal .  

paperclap

Ended up using the Timco stuff. Really nice to work with!

greenface2

paperclap said:

Ended up using the Timco stuff. Really nice to work with!

thanks for the update . Timco have a good name . I knew Tim from way  back so far I care to remember , Mid to late  80s I was  charge-hand of a large solaglass branch . We used to make up orders even if we didn't need them at the time because I used to get my stuff for next to free off them . 

peewhyeff

paperclap said:

Ended up using the Timco stuff. Really nice to work with!

Can I ask which product in particular?  Timco is not a brand I've heard of, and our sealant is getting tired.