Consumer reports "buying guide" for replacement windows recommends fiberglass or wood windows over vinyl. I've also heard from various sources that some vinyl windows can warp with expansion and contraction over time.

I'm wondering if I should avoid vinyl replacement windows in general? Do people's bad experiences with vinyl stem from the cheaper end of the spectrum? Do quality brands of vinyl windows exist?

There seems to be a lot of potential propaganda/fear-mongering/crazyness about vinyl windows on the Interwebs. For example here. These websites make my bs detector go off... It seems hard to find a non biased opinion on the subject.

3 Answers 3


There's an issue to be concerned about in high-crime areas -- they're plastic, so they can melt. Someone interested in breaking into your place can take a torch, heat up the frame of the window, and push the window or the whole sash in. Some vinyl windows aren't all vinyl, and have an aluminum or steel core, that might reduce this from being able to happen.

Also, vinyl isn't good for high-heat areas. A south or west facing window in a hot climate might heat up enough through the day that it'll warp. This is even worse in dry areas with large high/low shifts each day.

In colder climates, vinyl becomes brittle, which means if you're in a windy area with gets a lot of blowing wind, you could get debris thrown into the window which can crack the whole frame; and unlike other construction, you can't just replace the glass, you have to replace the whole sash.

Vinyl on its own isn't all that strong -- so there's a lot of vinyl involved -- if you're trying to get a lot of light into a room, you'll be able to get more glass into the area with just about any other material.

You also can't paint them easily. Whatever color they are, that's what they're going to be unless you replace 'em. This isn't typically a concern for most people, though, as most vinyl windows are white -- but they'll slowly yellow over the years, depending on the exact mix of vinyl. This is more pronounced in areas with higher UV indexes. (eg, high elevations with no shade trees)

Vinyl also outgasses. If you've got someone in the family who's sensitive to chemicals, this could be an issue.


That's not to say that there aren't different qualities of vinyl windows, but don't just buy on price -- look at internal metal stiffening, if it's welded or screwed together (you want welded), if it's fully encased in the vinyl (so it won't oxidize), and there's certifications now for vinyl windows ... but I think it's an industry effort, so I don't know for sure how reliable it is.

  • 3
    If someone wants to break in, can't they just break the glass anyway?
    – Doug T.
    Sep 7, 2010 at 15:14
  • Also Joe, are you familiar with sliding glass doors with fiberglass structural support? How would that compare with aluminum/steel. Specifically we are looking at Sunrise windows.
    – Doug T.
    Sep 7, 2010 at 16:01
  • 2
    @Doug : unlike breaking glass, it's quiet, and burglers have a lower risk of injuring themselves. As for fiberglass windows, sorry, I have no experience with them. (Although, I have done fiberglass lay-up in the past, so I know it's plenty strong if done right; stronger than aluminum by volume and steel by weight ... and weak if done wrong)
    – Joe
    Sep 7, 2010 at 16:41
  • @Joe well the window itself is not fiberglass, it is fiberglass reinforced PVC. See the question I just posted here: diy.stackexchange.com/questions/1665/…
    – Doug T.
    Sep 7, 2010 at 17:31
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    Security: I don't think heating the window and pushing it in is going to be any criminal's choice of entry - a bump key (see en.wikipedia.org/wiki/Lock_bumping) is going to be MUCH easier and less suspicious than carrying around a torch. Security isn't a real concern here. Sep 8, 2010 at 19:52

As with anything, quality counts.

The benefits of vinyl (or uPVC as they're called in the UK) is that they require less maintenance than wooden windows.

However, a properly maintained wooden window will outlast a uPVC window - it's just harder and more time consuming (sanding, painting etc.) to to.

I have heard stories of uPVC frames that were made without a metal (usually aluminium) core - which would warp badly - but I've no evidence to hand.


Buy quality, name brand windows.

The previous owners of my house installed vinyl windows in 2002. They are all breaking in one form or another. Either from warping, broken tilt-in latches leaking seals, or any of about a half dozen other issues.

An extra $50 a window would have gotten Andersen, Pella or Marvin windows with 10-15 year warranties that would still be working great.

  • 1
    We had newly installed vinyl windows in our house we werer renting about 3 years ago. One latch broke (it won't stay unlocked, so you have to fiddle with it every time you open the window) almost immediately, and two other ones also now exhibit this behavior.
    – r00fus
    Oct 1, 2010 at 19:44

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