Anyone use plastic window/door pans?
jimblodgett
| Posted in Construction Techniques on
I have seen manufactured window and door pans at various trade shows over the past few years and often thought “that’s a good idea, especially under a door”.
So I go to www.astroplastics.com just now to see what they cost and they seem reasonable enough – less than 10 bones an opening, cheap enough insurance, but I just can’t pull the trigger and order them.
I’ve taken plenty of doors out over the years that could have benefitted from a pan under the sill, but very rarely have I see the framing around windows deteriorate in the same way.
How about you? Any of you professionals use these pans in every window opening?
Replies
i tried some of them...they seemed like a good idea
they took up too much room and gave us some problems because of it
we went back to Grace
I once trimmed out windows that someone installed over Jamsill pans. The bottoms of the windows were all kicked out a hair while the tops were in tight, because of the thickness of the plastic. On my own installs I either use Flexwrap or a 24ga galv pan.
I've had the same problems with Jamsill, it kicks out the bottom and makes trimming out difficult. We usually use Grace now, or copper or lead for high-exposure areas.
Some of the manufacturers are carrying their own lines that are lower profile than Jamsill.
Pans under windows are cheap insurance. My favorite detail is to put a clapboard on the rough sill to create a slope, then Grace over that.
Tyvek's Flexwrap makes a good sill pan because you can just stretch it around the opening.
I've used jamsills. They are fine for a full depth door (4 9/16" jamb or 6 6/16) but dont work with a vinyl slider since the jamb is shallower and you get a gap betweeen the rear lip of the pan and the door itself.
You still see the plastic lip on the back side of the door which is not preferred.
Re. windows, I build pan with Grace or equivilent on a sloped sill (horsefeathers or tilt the bottom framed sill out to ensure water will drain out when it hits the sill)
I have not seen a lot of rot around windows with vinyl or aluminum siding but have seen nightmares around stucco.
Granted there were lots of issues that cause the leaking with stucco but I watch every part of the system now that I have been to construction hell and back. (stucco issues in the Northeast specifically the philly suburban areas)
I have seen expensive new construction windows leak immediately. The aluminum clad/wood windows that we install most of the time are made with miters at the corners of the frames, and if those don't leak now they will later. I figure if I don't install a sloped pan under every one of these things I'll be seeing the magistrate.
What are horsefeathers?
I guess I just don't see how water gets to the sill in the first place. Granted, once it gets there, a sloped sill, or some type of pan, seems logical. But that's too late, isn't it? Hasn't the building envelope already failed?
And what about the nailing fin? Doesn't that restrict water from draining out onto the housewrap or felt?
I go to these seminars, and watch produst demonstration after demonstration and they confuse the ship out of me. I think I know how to stop the initial water intrusion, but it certainly isn't what I keep seeing demonstrated.
I like flexible self adhesive wrap under door sills, but I just don't get it under a window.
Never have delt with stucco - before or after construction.
David - "horsefeathers!" is what Elmer Fudd says, isn't it?
Jim
Think of windows as a big gaping hole. They do 1 thing. LEAK!!
If they dont leak when installed, they will leak after a few years.
Do a dam test and you will see. put a piece of tape across the sill of the window and fill the sill up with water.
Almost every window you test will allow water to leak thru the edges if it is a wood window.
Vinyls might not leak in the beginning.
Manufacturer will tell you that is not a valid test of the window, but shucks, if it leaks it leaks.
My method of installation is silicone sides and top to the sheathing, and dont silicon the bottom flange. (so water can drain)
Top and sides behind the tyvek or wrap and bottom is on top of the wrap and pan.
Real important to make sure the wrap is up under the pan under the window. I've seen a lot of people put the pan in and then tyvek over the pan so the water that gets on the pan just dumps out and onto the sheating behind the wrap. (brilliant!!)
I don't but sticky tape #### on the top and sides of the window. I will tape the head but tend not to tape the sides of the window unless manufacturer requires it to be taped.
Problem is manufacturers dont tell you that this is the way to put the window in so since you are not abiding by their recommendations, you mght void warranty.
It is a sticky wicket this water intrusion issue!
"My method of installation is silicone sides and top to the sheathing, and dont silicon the bottom flange. (so water can drain)Top and sides behind the tyvek or wrap and bottom is on top of the wrap and pan."I think the paper (or housewrap) should go behind the nailing flange (ecept on top). And I like taping the side and top flange to the wrap after that. Redundancy. And drainage.As for these joints in aluminum cladding that leak, I think that is a poor cladding detail. In fact, that is one of the things I never liked about Pella windows and doors. Now you guys are saying Marvin, Anderson and other are using that detail? I don't think I'd warranty windows made that way, so I guess I couldn't sell them.
The clad/wood windows I have handled all have joints at all four corners. They are not magic, waterproof joints, so I just plan for the eventual leak and put in pans. I'm surprised your clients are not asking for these windows. What are you installing?
Mostly vinyl. Fiberglass when I can convince them.Current customers took a hard look at Marvin AL clad wood, but decided against them.Personally, I'm no fan of the pine interiors most wood windows use. Never have been. I DO like the vg fir (have to bow my head when I say that) Lowen, Milguard and probably others use, but would still only recommend something with vinyl, fiberglass or other exterior cladding like the one Kolbe&Kolbe has..."K Kor" or "KKron" or something like that. I have no practical experience with K&K but they look great in the showroom.
Nothing wrong wiht your method.
I am not partial to if the window is silconed to the sheathing or the tyvek, but I have seen some manufacturers require it be siliconed to the sheathing for wind requirements. (crazy but whatever)
I like the idea of taping, but dont do it consistently. (certainly a belts and suspenders approach but that is not a bad thing)
Re. windows, I'd suggest you just pan em all and figure they all will leak.
Jim, I guess it depends on what type of windows you are installing. The higher end AL clad/wood windows--Marvin, Anderson, Loewen, Pella, etc.--are made with joints at the corners, and sealant. How long do you expect the sealant to last? What if they didn't put enough on in the first place? I can tell you with 100% certainty that leaks thru the frame with those types of windows are going to happen, whether it's today or in 20 years. It's only a failure of the building envelope if the leak gets the wood wet. If you install a pan that drains out over the felt, or even out over the siding, you are doing the right thing.
Vinyl windows have welded corners. They actually seem to me less likely to leak in the short term than a more expensive window. I still pan them anyway. Thermal expansion/contraction could break the weld over time.
Old fashioned double hungs with the big 8/4 sloped sills might be the least leak prone. I have made and installed those but it's rare.
If you get a roll of Flexwrap and some 1/2 x 6 cedar bevel siding you are ready for whatever.
Edited 10/19/2008 12:20 pm by davidmeiland
Edited 10/19/2008 12:20 pm by davidmeiland
One of the weak points in windows is the joint between the siding and the window sill. Most windows have a rabbet to slide the siding up into, but with shingle siding especially that area is vulnerable in a driving rain. I don't know if you guys get hurricanes out there, we don't very often here but at least once a year on the coast there is a storm that's close to hurricane force. Regular top-down rain may not be a problem, but horizontal and upside-down rain will find holes if they are there. A house I designed that is just about done, right on the ocean, leaked through the windows in one of those storms.
Yeah, wind driven rain is a whole other issue. I don't envy you folks who build for those conditions.Of course, the job site scenery is nice!
Jim,I do a piece of bevel siding on the rough sill, a run of Vicor flashing tape along the bottom, about a 16" piece of flexwrap around the corners only, because it's so expensive, then up the sides with Vicor. I almost never used flanged windows. Mostly wood double-hung with 5/4 x 4" casings on the greek revival and victorians around here.Often I'm dealing with a house with no sheathing, just claps on studs. I that instance, I lap the bottom and side pieces of Vicor over the top edge of the closest piece of siding to the bottom, then cover that with the next piece of siding.The double layer of wrap at the corner does kick the bottom of the window out a tad, though.Steve
"Jim,
We do Vycor head and sides to galvanized pans on our doors and Vycor on the windows, double layered. 9" on the sill and 6" on head and sides before window goes in, then 6' on the head and sides again before siding paper, never housewrap and always plywood. The bottom of the 9" has the paper left on so the sider can slide his paper underneath. I tried those adjustable plastic pans before and didnt like how stuck up above the finished flooring and trimming them is a real pain.
So except for at the bottom of the window, you install your paper over your top layer of Vycor?
That's correct. If the exterior finish is stucco, that contractor papers over the Vycor and then applies his flexible flashing. It's a lot of built up material, but it's the best way we've found to seal the envelope. I see David's point with the sealing of the clad corners when the window is assembled at the factory. The only thought that I can add is that the caulking/sealant is usually filled solid from the back of the cladding to the wood window frame.
Seems to me it would shed water better if the top layer of Vycor was outside the paper. Seems like water could get behind the paper the way you describe.
Am I missing something?
Sorry, I wasn't clear. I omitted that the siding/stucco contractor then seals his paper to the vycor that was installed previously.
Okay, I'm going to play the devil's advocate here. Let's say you install the house wrap or felt and the pan perfectly. Where does the water that passes through the window go? It goes down the pan and ends up between the house wrap or felt and the siding beneath the window. Where does it go from there? I'd say it would most likely seep into the dozens of perforations in the wrap created by the nails holding the siding in place.
In my experience, window and door leaks are usually caused by poor or missing flashing above the window. Assuming that these are installed correctly and that the vertical siding/window joint is properly caulked, the second most important factor is having a rake or eave overhang above the window or door.
On one of my jobs, I gutted a kitchen on a 75-yr.-old house that had been through Hurricane Hazel (1954) and Huricane Fran (1996) as well as countless severe thunder storms. The house had no sheathing. The siding, southern yellow pine boards, had been nailed directly to the studs. These provided rack resistance. The windows and doors were also nailed to the frame.
The room had a window, which I eliminated. There was no sign of a leak and no rot. The reason there was no damage was because the window was just under a 2-ft. wide eave.
There's nothing wrong with the details that are so often discussed here. But the emphasis should be on keeping as much water away from the opening as possible (with eaves, rakes or porch roofs) and by diverting any water which runs down walls towards the tops of windows or doors with carefully detailed flashing.
mud..... <<<It goes down the pan and ends up between the house wrap or felt and the siding beneath the window.>>>>
if your pan flash doesn't dump the water back onto the top of one of the siding courses ......and then back out to the surface... then you have an incorrect flashing detailMike Hussein Smith Rhode Island : Design / Build / Repair / Restore
"If your pan flash doesn't dump the water back onto the top of one of the siding courses ......and then back out to the surface... then you have an incorrect flashing detail"Mike, suppose there were a rainscreen gap between siding and wrap. In that case, should the pan still dump water onto a siding course, or is that occasional bit of water ok to dump into the gap, since it can flow down and out freely?
i've never done a rainscreen ... how do they detail it ?
just take a window sill for example....
a traditional sill is an integral part of the window
the sill has a rabbet that the siding goes into
the water runs down the sill.. cappillary action pulls some of the water around the sill
to the rabbet
it flows onto the siding tucked into the rabbet and flows down and out
in the corners of the rough opening are two pieces of metal usually let into saw cuts in the jacks and sheathing
this metal sheds onto the top of an underlying course
if you are doing a modern nail-fin , then at the bottom you have to have the integral flash that is part of the window lap onto a siding course... or extend the integral flash with say... Grace I&W.... leave the release paper on the flap portion so you can tuck a course of siding under it
with a rain screen these details have to be extended out to the drain plane
so how is the window casing applied ? does it interrupt the rain screen ?
is it thicker to allow for the depth of the rain screen ?..... how does the window sill detail integrate with the rain screen ?
hmmmm...... maybe rain screens are not all they're cracked up to be
Mike Hussein Smith Rhode Island : Design / Build / Repair / Restore
if your pan flash doesn't dump the water back onto the top of one of the siding courses ......and then back out to the surface... then you have an incorrect flashing detail
Mike, One would think. But that's not the way it is generally shown. Check this site out, for instance:
http://www.jamsill.com/pilot.asp
mud... two examples of incorrect flashing details
the pan flash has to carry the water out to the surface
it usually means integrating those mfr'd systems with some kind of flap that siding can tuck under
how flashings terminate at their lower end is one of the details i see get screwed up most often
for example... step flash ending at a siding extension.... most just stop... and bury the flash behind the siding
it requires a kick-out flashing to make it work... same thing with a pan flash
what do you do on a deck with say , a sliding door ?
a good detail is the door is above the deck about 5 " - 6 "....... there is a pan flash
and a kick board...... how do you protect the kick board ? we usually make the kick board out of Trex or something similar... because it is at risk from water getting behind it
or you can extend the pan onto the top of the kick board... either way is awkward....
this is one reason copper is often used.. because it works AND it looks goodMike Hussein Smith Rhode Island : Design / Build / Repair / Restore
Here's another one. Google sill pan. The instructions for all the products I've seen have the pan ending behind the siding. This would be fine if there's a rain screen.
http://www.building.dow.com/na/weather/prod/wm_sill.htm
"horsefeathers!" is what Elmer Fudd says, isn't it?
http://www.youtube.com/watch?v=M8Q4IxITJZ4View Image
Yep David.
I am on the same page as you re. windows. I have experienced those leaks and with stucco it is just way too much risk.
I have ripped apart homes with vinyl siding for renovations that have been leaking for years but the wind blows and the wood dries out. 20-30 year old homes with little or no damage. No mold growth, maybe a little staining. I've ripped apart stucco homes that were 2 years old and the OSB is shot.
Anyway, horsefeathers are about 3' long shims. The taper is across the shim not longitudinal and they are about 3" wide.
I dont know why they are called horsefeathers but that is what the old timers around here call them. I am sure there is a story behind it.
It's just so easy to make them up out of galvanized flashing that I don't see the benefit to waiting to order the right number of plastic ones. Just show up on the site with a roll of flashing and knock out as many as you need in what ever size the RO's are. Don't use aluminum for this though, it's not stiff enough to slide a door around on.
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"You cannot work hard enough to make up for a sloppy estimate."
Grace is hard to beat, but I know of many high quality finish carps who insist on a pan of some sort.
Beer was created so carpenters wouldn't rule the world.