Keylite frame material

[cwr]

Hi all

I am considering fitting Keylite roof windows, but am wondering if I should go for uPVC or wood frames. The uPCV are more expensive and can (if you pay for it) have a longer warranty. So are they a better frame? 

[dpmiller]

We've got the PVC frames and they're very good. Obviously they're near-enough maintenance-free, and are clean and bright. You'd need to go digging to confirm, but they're probably a bit better thermally?

[Conor]

We've the PVC as well. Don't see why you would want wood, unless for the look or you wanted a different colour.

[cwr]

Thanks for the replies.

 

I've just found out that the top hung Keylites are only class 3 for airtightness. Don't know how good or bad that is? I got 0.92 for the whole house so don't want comprise on that.

Apparently Velux are class 4 for the equivalent product, but are more expensive. 

[dpmiller]

are they like-for-like, both with top vents?

[cwr]

And just found out that keylite centre pivot ones are class 2.

[cwr]

Does anyone have the exact definitions of these classes? 

[dpmiller]

No idea how the numbers work but our PVC centrepivots have pretty complex seals, one wiping, one compressive .