Leaking picture windows

Sunbeam lodge · 08-11-2015, 12:24 PM

I have a huge glass front wall broken up into diagonal sections composed of wood and glass. The bottom section is made up of sliding glass doors.
Whenever we get wind driven rain water leaks somewhere around the windows and ends up in the sliding glass door sills. We need someone that can determine where the leaks are coming from and seal the windows to prevent future leaks. Can someone suggest a company that does this type of work?

DickR · 08-12-2015, 12:20 PM

I have no suggestions as to who can do a good job of diagnosis and repair. But you can figure that unless there is one place of leakage that is obvious by external examination, then a proper job may well involve removal of siding, trim, and Tyvek or equivalent WRB (water-resistive barrier, or "housewrap") from the whole wall, reflashing (properly), and reinstallation/replacement of everything removed. This probably isn't a morning's job for someone, so it likely will be expensive.

Locating leaks often is not an easy job, as water can migrate some distance from the point of entry. Conceivably there is a leak at the roof, and the water is finding its way down. But my first suspicion is improper window flashing.

Historically, proper window installation has been more the exception than the rule. In many cases, leakage doesn't occur only because the wall has adequate protection from wind-driven rain, due to a generous roof overhang or a close row of trees. In other cases, leaks occur but either the water dries out rapidly enough or the damage occurs so slowly that years pass before discovery. In the case of one house not far from me, one perhaps ten years old at the time and built by a "known" builder, the water damage was discovered when a whole patio door assembly fell out onto the deck. When I saw the demolition debris pile, I saw that the rot was halfway across the width of the 2x6 framing members; there was nothing left for the nails to grab. The presence of carpenter ants sometimes is a clue to hidden water damage in a wall.

The major window vendors now publish installation instructions, to cover themselves against warranty claims. You can review these instructions on any of their websites; the procedures don't vary too much. What you see is careful attention paid to having all the layers "shingle-lapped," so that any water that gets onto any layer behind the siding is directed over the layer below that and can't get behind any of the layers.

Despite all the available information on how to do it right and common sense, I still see window installation done in new construction with at least something wrong. One common mistake is to have the top window flange outside of the WRB, with a strip of self-adhering flashing tape applied over the joint. Any pucker in the tape or separation from the WRB can lead to water getting behind the flange. Wind-driven rain can and will get behind almost any kind of siding; that's why a WRB is required. Proper installation technique calls for the WRB to be lapped over the top flange before any tape is applied. Another mistake is taping over the bottom flange. If any water should get behind the window assembly, it must be diverted out over the WRB over which the window was installed; if that joint is taped, the water can't get out.

Assuming you will be having a contractor come in to do the work, you at least can read up on how things should look behind the exterior, so that you can have an intelligent discussion with the contractor on what he will be doing, as part of contractor selection. Not all of them know as much as they ought to. You will be in a position to follow the work as it is done, pointing out any flaws before they are covered up. They may not like that, but it's your house and you are paying the bill.

Later, after things are fixed, post something here on what was found and what was done to fix things.

ApS · 10-06-2015, 07:12 AM

Quote:

Originally Posted by Sunbeam lodge

I have a huge glass front wall broken up into diagonal sections composed of wood and glass. The bottom section is made up of sliding glass doors. Whenever we get wind driven rain water leaks somewhere around the windows and ends up in the sliding glass door sills. We need someone that can determine where the leaks are coming from and seal the windows to prevent future leaks. Can someone suggest a company that does this type of work?

Maybe you don't have a wall/window leak...?

Sliding glass door sills are designed to release any wind-driven rainwater. Water collecting there should go out multiple "scuppers"—unless they are clogged by Hemlock debris. It could help to enlarge them or even add more.

One side of our lot is heavily rooted with big trees. They do a good job of knocking down wind-driven rain; however, the front of the cottage faces open water, so we can get a drenching all the way up the exposed wall!

Even with our ten-foot roof overhang, wind-driven rain gets blown under our front door, in spite of seals at the screen door, and heavily-redundant front door seals. It's the price we pay for a wide view of the lake.

noreast · 10-06-2015, 05:26 PM

I bet it's the flashing. It's amazing how often it's done improperly.

08-11-2015, 12:24 PM	#1
Sunbeam lodge Senior Member Join Date: Apr 2004 Location: Meredith/Naples Florida Posts: 367 Thanks: 135 Thanked 50 Times in 26 Posts	Leaking picture windows I have a huge glass front wall broken up into diagonal sections composed of wood and glass. The bottom section is made up of sliding glass doors. Whenever we get wind driven rain water leaks somewhere around the windows and ends up in the sliding glass door sills. We need someone that can determine where the leaks are coming from and seal the windows to prevent future leaks. Can someone suggest a company that does this type of work?

08-12-2015, 12:20 PM	#2
DickR Senior Member Join Date: Apr 2008 Location: Moultonborough Posts: 757 Thanks: 4 Thanked 259 Times in 171 Posts	I have no suggestions as to who can do a good job of diagnosis and repair. But you can figure that unless there is one place of leakage that is obvious by external examination, then a proper job may well involve removal of siding, trim, and Tyvek or equivalent WRB (water-resistive barrier, or "housewrap") from the whole wall, reflashing (properly), and reinstallation/replacement of everything removed. This probably isn't a morning's job for someone, so it likely will be expensive. Locating leaks often is not an easy job, as water can migrate some distance from the point of entry. Conceivably there is a leak at the roof, and the water is finding its way down. But my first suspicion is improper window flashing. Historically, proper window installation has been more the exception than the rule. In many cases, leakage doesn't occur only because the wall has adequate protection from wind-driven rain, due to a generous roof overhang or a close row of trees. In other cases, leaks occur but either the water dries out rapidly enough or the damage occurs so slowly that years pass before discovery. In the case of one house not far from me, one perhaps ten years old at the time and built by a "known" builder, the water damage was discovered when a whole patio door assembly fell out onto the deck. When I saw the demolition debris pile, I saw that the rot was halfway across the width of the 2x6 framing members; there was nothing left for the nails to grab. The presence of carpenter ants sometimes is a clue to hidden water damage in a wall. The major window vendors now publish installation instructions, to cover themselves against warranty claims. You can review these instructions on any of their websites; the procedures don't vary too much. What you see is careful attention paid to having all the layers "shingle-lapped," so that any water that gets onto any layer behind the siding is directed over the layer below that and can't get behind any of the layers. Despite all the available information on how to do it right and common sense, I still see window installation done in new construction with at least something wrong. One common mistake is to have the top window flange outside of the WRB, with a strip of self-adhering flashing tape applied over the joint. Any pucker in the tape or separation from the WRB can lead to water getting behind the flange. Wind-driven rain can and will get behind almost any kind of siding; that's why a WRB is required. Proper installation technique calls for the WRB to be lapped over the top flange before any tape is applied. Another mistake is taping over the bottom flange. If any water should get behind the window assembly, it must be diverted out over the WRB over which the window was installed; if that joint is taped, the water can't get out. Assuming you will be having a contractor come in to do the work, you at least can read up on how things should look behind the exterior, so that you can have an intelligent discussion with the contractor on what he will be doing, as part of contractor selection. Not all of them know as much as they ought to. You will be in a position to follow the work as it is done, pointing out any flaws before they are covered up. They may not like that, but it's your house and you are paying the bill. Later, after things are fixed, post something here on what was found and what was done to fix things.

The Following 3 Users Say Thank You to DickR For This Useful Post:
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10-06-2015, 05:26 PM	#4
noreast Senior Member Join Date: Mar 2015 Posts: 648 Thanks: 316 Thanked 120 Times in 93 Posts	I bet it's the flashing. It's amazing how often it's done improperly.

The Following User Says Thank You to noreast For This Useful Post:
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