Wood Replacement: Too Much Glass Lost

iflyvfrMarch 20, 2012

Last week we looked at Jeld Wen & Kolbe replacement DH windows. From searching the forums, it appears JW is junk or slightly above, and Kolbe better.

When they showed us the amount of glass we would lose by installing a replacement Jeld Wen -vs- the Kolbe sash pack, it looked to be at least 2" on each side! That to us results in a LOT of lost glass and we are left with a narrow window sitting inside our old frame. To us, it looks unnatural and unattractive.

We want wood, and we want to be able to tilt and clean them. Our sashes & frames appear to be in good shape. Any other suggestions, makers, or ideas? I just checked Marvin and they have a sash pack for example.

Is tear out our only other option to preserve the glass space? We might have priced ourselves out of windows if so and we dont' want to sacrifice the historic character of our home, that is very important to my wife.

Thank you for reporting this comment. Undo

Marvin offers both a sash pack and a pocket replacement option. For installation, performance, etc, I always prefer to install a full frame. If glass loss is a major concern, the only other option (besides a sash pack) is indeed a full-tear out. The price difference and intrusive nature of the install is typically enough motivation for most to disregard the small amount of glass loss, but each home and homeowner has different circumstances and priorities.

    Bookmark   March 20, 2012 at 10:39PM
Thank you for reporting this comment. Undo


When you say you want wood, do you want to have a clear finish on it or are you going to stain it? I am asking b/c someone who sells Kolbe told us that Kolbe wouldn't look right in our windows either. They said that if we were going to paint then cellular PVC sash replacements will look just as good. I have seen some and couldn't tell the difference from 2-3 feet away. Perhaps, I should have put my glasses on, LOL.

Just wondering...

    Bookmark   March 21, 2012 at 12:12AM
Thank you for reporting this comment. Undo

It isn't a small amount of glass loss. It's a lot. And depending on your window style and size, it can be very noticeable. A full frame tear out and rebuild doesn't have to be overly expensive, and you should check out that option, along with checking out fiberglass frame options. The frames will be much more narrow than vinyl.

    Bookmark   March 21, 2012 at 12:36AM
Thank you for reporting this comment. Undo
Windows on Washington Ltd

Window dog,

Most original window buck frames are 3/4" on either side. This 1.5" total width recovery is not worth the added investment in all the interior trim and carpentry for many consumers. I also take issue with several of the applications where folks are ripping out full frames and disturbing what was a functional nailing flange head lap for water management.

If you are replacing siding or similar exterior modifications, a full tear out and replacement with complete new construction window (nailing flange, flashing, drip cap, j-channel, etc) is an absolute preferred methodology.

Fiberglass frames are not "much" more narrow that vinyl. We have had this discussion on the other forums and I told you the same thing over there that I will here...1/4" of and inch on either side is not what most would consider "much".

VT rating on narrow profile vinyl insert with two coat low-e and no grids is 0.55

Same VT rating on a similar insert Infinity window with a two coat low-e and no grids is 0.56

Hardly seems like "much more" light.

Before you attempt to say that I am trying to just kill fiberglass because we sell vinyl, we sell Infinity and have done quite a few jobs in it. It absolutely is a beautiful window and for those clients that want it, it meets all of their needs and aesthetic requirements.

That being said, I would never sell it as "much more" narrow than comparable vinyl.

The only real "much more" descriptor when referring to the Infinity that I can think of would be air leakage which is the unfortunate drawback to that window.

    Bookmark   March 21, 2012 at 9:22AM
Thank you for reporting this comment. Undo

^Ditto.^ :D

    Bookmark   March 21, 2012 at 10:21AM
Thank you for reporting this comment. Undo

I just did a job replacing a vinyl patio by Simonton that had over 5" of vinyl before the glass started. I'll admit I'm not familiar with any low profile vinyl products.

I'll agree with you on the installation fin issues, because the fin acts as a drip cap, and most installers do not do a drip cap installation, or flash anything. California has outlawed removal of aluminum frames for this reason, as you know. Although I don't think leaving the old frame in is so great either.

The loss of glass space is not a major issue with larger windows. Say what you want - I installed thousands of vinyl windows, and more times than not the first thing out of a customer's mouth is "I didn't realize I would be losing so much glass".

Concerning air infiltration/leakage, to use the phrases "bulk" or "much more" is not so honest. Laboratory testing is one thing, real life is another. Vinyl windows with great numbers can be put in incorrectly or change shape in the sun and that .19 window can leak air. If you are in the vinyl business then you know that happens. I agree that top of the line vinyl will have better longevity, but you know that most people cannot differentiate between these products.

Please keep in mind that I'm with you in most respects. In many situations, a top quality vinyl product is entirely the appropriate solution for someone's home. I agree with that. Also, keep in mine that Renewal is the highest priced window out there, not Infinity. My opinion of Renewal and fibrex is lower than mid-grade vinyl. It's a genius PR campaign with "industry experts" that have no hands on experience and don't know anything buy laboratory numbers. Talk about massive air leakage.

I'm trying to avoid getting on a fiberglass features jag and leave that up to people to learn for themselves. I certainly can do that, though, if you guys want to keep throwing out "air leakage" at me. I don't know if you're familiar with I-80 through Wyoming, but it's an air tunnel. 50mph winds are normal. It can be brutal. You guys back east would go into national emergency, and I know that because I live on the east coast for 20 yrs. I was in Rawlins WY a couple days ago to photograph and inspect an Infinity job we did for a customer who got taken for $5000 by a "top of the line" vinyl company that then went bankrupt. No windows and no money back. Anyway, my point is, they are dead center of the windiest part of the country and they have no air leakage through the windows or the patio door. They also have the beauty of the home looking like the windows were never replaced, while all their neighbors have fat bulky vinyl frames. I'm just saying.

Now, between you and me, in that neighborhood, was fiberglass worth it? It depends. We were less than Champion, who is gouging people out here left and right. We try very hard to keep our costs down and stay competitive. We were a lot more than the company they originally went with, but that was a 5k loss.

All factors must be weighed. I'm glad you carry Infinity as an option in your line, because it is a great option.

    Bookmark   March 21, 2012 at 10:21AM
Thank you for reporting this comment. Undo
Windows on Washington Ltd


It is not my intent to get into an argument with you. That being said, millions of viewers read this forum so I think it is worthwhile to make sure that we deal in facts so that future readers can make decisions based on that rather than opinion.

For the sake of future discussions into the comparison of fiberglass vs. vinyl, lets assume that we are comparing the premium versions of vinyl. Comparing some cheap, builders grade junk vinyl to fiberglass is not a level comparison from the outset.

The fact that you have installed thousands of vinyl windows in which the customers have commented about glass loss is great, however, if done as a comparable insert installation, the Infinity provides very little advantage when compared to narrow line vinyl. If you were installing a vinyl insert with a edge of frame to glass dimension of nearly 4", then yes...customers are going to note a difference.

Using that as the benchmark and therefore basis of the statement that you loose much more glass with vinyl is accurate in that application but false as a whole.

As I noted above, the Infinity only provides you with 1/4" more glass per side as compared to narrow line vinyl and a whopping 1% more visible light.

Sunrise is one of the more well regarded windows out there and nearly all of its product lines will have very similar reveal and dimensions to the Infinity. Couple this with the fact that it is much more airtight and achieves much better thermal numbers and I think that a customer would likely choose the more performance yielding windows at the expense of 1/4" and 1% light.

Much more is certainly an apt description for the Infinity's air leakage number. Most of the premium vinyl windows out there on the market have air leakage numbers that are 0.05 and below. An air leakage number of 0.19 does not even approach the performance of the better units out there.

The Infinity, by comparison, has and air leakage rate of 0.27 based on the AAMA test report that I have in my hand of their insert window. It also has a DP30 rating. Interesting performance out of a window that is supposedly 8X as strong as vinyl (an often quoted data point on their site although it is referring to tensile strength and that is a completely unrepresentative force that is ever placed on a window installed in an operational capacity).

It the material for the Infinity is so superior to vinyl, why the low DP rating and the high air leakage. The best explanation that I can come up with for the lower DP is that it begins to leak water at what is and equivalent rating of DP30 and is therefore assigned that rating.

Looking at the Sunrise again, it has an air leakage rate of 0.04. The Infinity's leakage rate of 0.27 is absolutely "much more" than 0.04 (a nearly 7 fold increase).

You mention that the degradation of vinyl window performance in the sun. This has been a well debated subject but without any real data. Heat of deformation on vinyl is over 160 degrees (far from normal conditions or even possible in about 99% of the country) and I don't see windows reaching those temps.

Until someone can provide me with a data report to indicate the degradation of vinyl performance as a result of normal exposure, I don't see it and it purely conjecture at that point. All windows will loose a measure of performance tightness over time because the weatherstripping seals will loose some of their pressure but that is window universal.

Again, I appreciate your personal experience and the conditions that you are exposed to, however, data and facts are just that and are laboratory generated. By comparison to the higher end vinyls out there, the Infinity leaks more air. It is enough to create and issue for the customer, probably not but, it does have a higher than average rate and I doubt you will ever see it being installed in a net zero energy home.

I would agree with you wholeheartedly that the RBA is a less than average window.

    Bookmark   March 21, 2012 at 11:28AM
Thank you for reporting this comment. Undo

My ditto was to WoW's comments btw ,lol

    Bookmark   March 21, 2012 at 11:32AM
Thank you for reporting this comment. Undo

I knew that, HS. haha.

WOW, I appreciate your detailed comments. I'm going to look into some of these numbers because they are different than mine.

I've only been in sales for a few years. The rest of my life was hands on. I've often been at odds with establishment/industry claims because of hands on installation, operation and performance "feel". I realize that's not a technical method. It is, however, very valuable. I've seen great product ideas and performance that craps out in the field.

To me, the numbers are only so important. I want to feel it in a house. I want to feel it's operation. I want to stand in front of it in the sun. I want to stand in front of it in a 60mph wind.

Correct me if I'm wrong, but design pressure ratings are determined by blowing 8 inches of rain per hour with 150 mph winds directly on a unit. While it sounds impressive, this may not reflect real world performance in daily 60 mph winds and 10 degrees F in Wyoming :) I will check into the numbers tho.

Again, appreciate the comments.

    Bookmark   March 22, 2012 at 12:16PM
Thank you for reporting this comment. Undo

WD, I have a similar background as you having started as an installer. I get what you're saying about the "feel" as well, and I'd also say that even the best window is only as good as its installation. Certainly, lab #'s are probably going to change in a window that is installed in a home due to multiple variables. That said, consumers need a way to take that variable out of the equation to determine differences on product alone (assuming equal installation), and that is where the performance ratings are very important IMO. Appearance, options, functionality are all considerations as well, and different consumers will give more weight to some areas than others based on their priorities and project goals. Just my $.02.

    Bookmark   March 22, 2012 at 2:21PM
Thank you for reporting this comment. Undo

The rep was out tonight. Very low key, which we like. He brought out two sample windows, a Kolbe & a Jeld Wen. To be honest I didn't love either one of them. However, both are available in a sash pack. He is going to quote us both ways. I am leaning toward the sash pack because of the preservation of our window width. So unless he can do me a great price on the tear outs, we'll likely go that approach regardless of mfg.

At the end the installer guy taking measurements handed me a brochure about lead abatement and told me we tested positive for it. :-(

Eleena, to answer your question, we have all white painted trim, but are thinking about highlighting the wood by staining from the factory.

    Bookmark   March 22, 2012 at 7:28PM
Thank you for reporting this comment. Undo
Windows on Washington Ltd


Your DP assessment is not quite right.

The DP rating of a window or door is based on laboratory pressure testing in pounds per square foot or psf.

Air, water, structural is a three part test that determines much about a window's overall performance. Air infiltration is the first phase, water penetration is next, and structural is the third part of the test.

Windows are tested for air infiltration simulating a 25mph wind or a 1.56PSF pressure load - air infiltration is treated separately from both water infiltration and structural and it is independent of the design pressure of the unit. Said again - the air infiltration rate in a window is not based on the design pressure rating of the unit.

Both water penetration and structural testing, on the other hand, are based on the window DP rating. Water infiltration is tested at 15% of the design pressure and structural is tested at 150% of DP rating.

What this means is that a window with a DP30 is tested for water infiltration at 4.5psf (15% of 30psf) while a window with a DP40 is tested at 6psf (15% of 40).

A window with a DP30 rating should be able to keep out rain when its driven by 42mph winds and a window with a DP40 should be able to keep out rain when driven by 49mph winds...so while water infiltration is DP related - and air infiltration is not - the nature of air and water infiltration is different.

The structural rating of a window is as much about the glass as it is about the frame and sash system. In order to get a higher DP rating the window manufacturer has to consider the thickness and possible heat-strengthening (or tempering) of the glass as well as the use of higher-end hardware and good quality sealants in the frame and sash system. But, interestingly, there is nothing in the structural rating that specifically requires that the unit be air-tight.

A window can leak air like a sieve and still achieve an excellent DP rating. Likewise a window that is sealed tightly can have a lower DP rating but excellent air infiltration numbers. Obviously there are also many units that have both excellent air infiltration numbers and a satisfactory DP rating (relating to both structural strength and water infiltration).

Simply stated, the relationship between DP and windspeed is -- "the ratios of the design pressures in psf are the square of the ratios of the wind-speeds in mph".

A window with a DP30 is rated to a pressure level equivalent to a 110mph windspeed, but it is tested (for structural) at a pressure equivalent to 164mph.

A window with a DP40 is rated to a pressure level equivalent to a 127mph windspeed, but it is tested (for structural) at a pressure equivalent to 190mph.

If you are curious about calculating the numbers yourself, a while back (at the request of a specific window company as a matter of fact) I wrote a couple of simple formulas that will allow you to do so...

If wind-speed is known, then:
W/25 * 0.0624 * W = psf
Where W = wind-speed

Or, if Design Pressure is known, then:
SQRT(psf) * 20.01 = wind-speed

    Bookmark   March 23, 2012 at 12:54PM
Thank you for reporting this comment. Undo

Its official. WoW is a nerd. LOL! Good info.

    Bookmark   March 23, 2012 at 6:22PM
Thank you for reporting this comment. Undo
Windows on Washington Ltd

Don't quote me on that but I think that was an old copied note I had from Oberon.

    Bookmark   March 23, 2012 at 11:47PM
Sign Up to comment
More Discussions
Window won't stay up
This is the rail next to the top sash: This is the...
Plantation Shutters Pros/Cons, need advice
Hi, I'm new to this website and owning a home so forgive...
Remove window film immediately?
My contractor has been installing my new Anderson Woodwright...
Dual pane window retrofit, for sound blocking, question on thickness.
Been looking at options on vinyl windows with better...
Scherer Bros Windows Rotting
We have just learned our bottom window sashes are badly...
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™