Hi all:
I want to have some new Simonton 9800 windows installed in my 1990 home. Since I am having siding and trim also done, the installer will remove the trim and have full access to the sheathing. Here is the question: Should a replacement window with or without nail fin be used?? I am getting conflicting advice. It would seem to me that a window with a nailing fin would be the best. This way, the installer can nail the fin to the siding and use screws through the window jambs as well. They will also be able to use ice and water shield over the nail fin and sheathing. Then the siders can come, do the housewrap over the ice and water, put on the trim and button things up. One installer who claims to be the best in the business and “it would be a mistake to have anyone else do this work” says a nail fin would problematic. He says that he would not be able to get injected foam into the cavity behind the nailing fin. Because he will size the window such that it goes in from the outside and fits against the drywall return without a gap, he says there is no way to get the foam injected from inside. He will not use fiberglass insulation stuffed in from the outside since he says fiberglass is never meant to be stuffed (I agree on that) and that fiberglass will allow leaks. He wants to use windows without the nail fin and says he will put ice and water shield against the sheathing and window frame. Then he says the siders will drape the tyvek over that ice and water shield.
I hope a real window expert can tell me which is the better approach. I had thought that the nail fin would be the best option since you have that nice “flange” around the window that could be sealed with caulk and ice and water, BUT I also see his point that if you want to use injected foam, having a nail fin and finished drywall inside the home, how do you get that foam injected? I asked him about partially driving in the nail fin screws so he could insert the gun into the gap but he said he could not insert the nozzle in like that and it would just not be practical to try and do that.
I asked him what AAMA standards would say and he basically laughed at that suggestion – and said that with so many different installation situation, how could they possibly have guidelines. I thought that was what their whole organization was about.
Please help. My head is spinning here and I need to make some decisions.
Replies
I gather that you have drywall "returned" to the window frame instead of having conventional window trim on the inside. That does make things more complicated.
Hi DanH:
Yes, no wood trim at all inside the house. Drywall on walls turns at 90 degree angles partially into window frame and then window frame butts up directly to backside of the drywall return. This particular installer wants to order windows such that they will actually be wider than the inside dimension of the return so the frame will be behind the drywall return without having to fill in any gaps with caulk. He was VERY proud to say the least about this and says may window installers will put in windows with huge gaps just so they can have the wiggle room to insert the window. I had explored other options such a full frame width windows but that would involve removing my drywall return and having to install wood trim. I felt that the drywall return would retain a more contemporary look to the home - plus one less worry about someone goofing up the job. Now, I see there could be some advantages to a full frame window since drywall would be removed, you could use a nailing fin, and have plenty of room to inject the foam from the inside before putting up the new wood trim. However, I think I will go with keeping the return, so any advice would be appreciated.
Edited 9/25/2008 4:00 pm ET by Will92
I see the contractor's point. It might be possible to retain the fins and drill holes in them for foaming, but it would be iffy.But lots of windows are installed without fins, and if you trust his work otherwise and he does a good job of flashing and sealing then to me (a non-pro) it makes sense to go with him.There are an appalling number of window installers who wouldn't bother to foam the cracks.
There is no absurdity that human beings will not resort to in order to defend another absurdity. -- Cicero
It would be wise to check your installer's references and see if you can contact a previous client that has had his windows for a long period. I am not familiar with Simonton windows, but they should have their own installation instructions available to you. Their instructions would supercede the AAMA guidlelines. AAMA calls for cavity insulation when you can access the cavity, but obviously, that won't work for you. Drilling holes in the flanges for expanding foam would be pointless, as it would be impossible to run a continuous bead. If the installer orders his windows so tight, then foam wouldn't be any more beneficial than caulking. (assuming 1/8" gap or so on top and sides, tight at sill).
Does your installer have a written no leak warranty? Have past clients used it successfully?
It is true that for years, windows have been installed with no flanges/fins, with great success. A lot of that is due the siding details, and nowadays, the building wrap installers.
It sounds as if you would be more comfortable using windows with nail fins, and leaving the sheetrock undisturbed. Find an installer that fits your mindset.
One last resort, that I have done on request, is install backer rod to perimeter of window (Or opening) and install window with the proper amount of compression on the backer rod. backer rod should be 1/3 larger than joint, and confirming that in window replacements is usually a hassle. Backer rod also should not contact the sealant, as sealant must expand with window frame.
Finally, it is important to ensure compatability of all sealants used, with adhesive flashings, building papers, window frames, spray foams, backer rods, ext foam sheathing... ad nauseam.
Hope this helped
David Franklin
AAMA certified, but there are plenty of long time carps/builders out there that I learn from everyday
I would like to thank everyone here for their very helpful and lengthy replies. I appreciate the time you have all taken to try and help educate me and provide input.
Since I posted this question, I have been trying to further educate myself by reading some of the articles on this site. Of course, I have further questions...
In one of the articles, it discusses installation of windows when the housewrap is already in place. They discuss cutting the opening in the housewrap and creating a flap at the top of the opening. Another article also discusses creating a sill at the bottom of the opening using Vycor that is also wrapped up the sides of the jambs. The window is then apparently fastened to the sheathing (on top of the housewrap) except for the top flap of the housewrap. Here, the nailing fin attaches directly to the sheathing - rather than to the house wrap covered sheathing on the other three sides (sides and bottom). Once the screws or nails are installed, the tops and sides are then covered with ice and water shield - like Vycor. Sooo, no I'm wondering if I should have the siding stripped first, then have the housewrap installed, and THEN have the windows installed. This way, the nailing flange can be placed on top of the housewrap in the designated areas. But then is the caulk simply adhered between the nailing fin and the housewrap? Otherwise, the windows will go in and then the housewrap will not be able to be inserted under the nail fin. Am I on track here? Getting very confused now. Does it matter? Can someone provide the proper order of installation of windows and housewrap now for me? Geez, do I need to buy a Taunton book now?
Lettusbee, your suggestion of backer rod around the perimeter is interesting. Is it stapled in place? What you said about ordering the windows tight also makes sense. Would a generous amount of caulk applied to the back of the nailing fin seal the gap against water AND provide insulation value?? This way, it sounds as if my drywall could be left alone.
It also occurs to me that maybe having the ultimate insulation achieved by foam insulation isn't that important to me. It is more important to me that they are sealed against water intrusion - so I don't get mold, etc. Is this reasonable?
Would molding look crummy if I go with the one suggestion to slightly cut back the drywall to allow insertion of the foam nozzle and then have the gap covered with molding. This guy actually might like that suggestion. Would it make more sense if I have the drywall removed to completely remove the drywall return and then have it restored by a drywall finisher? The reason I was interested in vinyl in the first place is because wood windows required the drywall return to be removed and then trimmed out with wood.
This has been a very frustrating experience for me. All I want is for the job to be done correctly. Although this last contractor has an ego the size of a planet, I do appreciate he brought up the problems with properly insulating a window (with nail fin) with injected foam when the drywall return is left intact. Other contractors I have requested to use nailing fins never mentioned this would be a problem - and I even did ask if they use foam - so how were they going to do it I now ask myself??
Edited 9/26/2008 1:57 am ET by Will92
I have been installing windows for the past 10 years.
Since you are having your siding replaced you have the perfect opportunity to have your windows installed correctly.
You have the right idea. The proper way to install windows is to leave the nail fin intact. (although there are some instances where that is not possible) This offers you a way to flash the window and attach it to the house correctly.
After the old window is taken out install flexible flashing at the bottom in a way that the siders can tuck their building paper underneath it. Caulk around the perimeter of the rough opening so that the nail fin is set in a bed of caulking. Use 9" flexible flashing on the sides and last flexible flashing on the top.
Typically what I do with sheet rock surrounds is to cut the sheet rock back enough so that I can get some type of insulation, I use fiberglass, between the window and framing. Then I trim the window out with screen moulding to cover the gap.
I can see why he doesn't want to use fiberglass insulation without the nail fin. With the window properly installed there should be no leaks.
The concerns that I have with a no nail fin installation are how the windows are attached to the house and what keeps the weather out.
Hope this helps. If you need any clarification let me know
2LarryM:
By flashing, do you mean peel and stick ice and water shield or aluminum or galvanized material (like drip edging)? It would seem one would want to put caulking on the nail fin facing the sheathing, push it to the wall and fasten with nails or screws and then apply ice and water around the perimeter of the window - over both the nail fin and sheathing.
Can you elaborate about cutting the sheathing to insert insulation? My hope is that the drywall return can be left alone (less chance to damage something) and simply have the window butt up clean against it. BTW, he said he didn't like fiberglass because he would not even be able to get it behind the nail fin and in the cavity unless he tried something goofy like taping it to the back of the nail fin. He also doesn't think fiberglass should be compressed into window cavities since fiberglass is meant to be loosely filled for insulation properties.
Yes, the peel and stick kind. I usually use vycor. It has a rip cord so that you can split the backing in half. That way at the bottom of the window you can use the sticky half under the fin (before the window goes in) and the other half (with the backing still on) will allow the siders to tuck their paper underneath and then pull the backing off and stick it to the paper.Sorry I wasn't clear on the insulating part of it. I didn't say anything about cutting the sheathing. I realize you would rather not disturb the sheetrock returns, but I know of no other way to get insulation between the window and the framing other than to cut the sheet rock back.If you go with a nail fin installation you may need to cut the sheet rock back anyway. unless the new window and the old window are the same depth from the fin to the inside of the window.As far as the caulking goes you can either put it on the back of the fin or on the sheathing it accomplishes the same thing.
I thought the ice and water shield would go on after the window goes in and placed over the nail fin flange and adjacent sheathing. No?
If I don't want them to cut the sheetrock to create the gap to inject the non-expansive foam, is there an acceptable way of installing a window without a nail fin? Could ice and water still be used and if so, how?
I'd keep the flanges, use Vycor, and do whatever I needed to do on the inside to insulate and make it look right..View Image
You are right the ice and water shield is applied over the top of the fin, but just on the sides and top of the window. On the bottom of the window the ice and water shield should be underneath the fin.There are companies installing windows without nail fins all the time. So some people are accepting it. It is a choice you will have to make. I don't think it is a good way to install windows because the only thing keeping the elements out is caulking and possibly the foam. There is also the way the windows are attached to the house. The ones I have seen installed that way are screwed through the frames of the windows and are readily visible, not to mention effecting the windows weep system.I have never used ice and water shield to replace the fins so I don't know how good and how long that seal would last. If it fails one is again just relying on the caulking to keep the weather out.I believe there is a greater chance for a window to leak if the nail fins are not intact. If they do leak, depending on the severity, the sheet rock returns may have to be replaced.This all based on my experience. Others may have different experiences. Ultimately the decision is yours.I know it can be tough to wade through all the info and opinions. I hope I have been helpful
Of course, they did make windows before nailing flanges, and managed to do OK somehow.
There is no absurdity that human beings will not resort to in order to defend another absurdity. -- Cicero
True, but the window frames didn't typically stick out past the siding.
Of course, they did make windows before nailing flanges, and managed to do OK somehow
Yes they were nailed in with the brick mold, had sash weights and single pane glass.
Very cutting edge.... 100 years ago.
Brick mold -- the original nailing flange.
There is no absurdity that human beings will not resort to in order to defend another absurdity. -- Cicero
I'm with Larry on this one. Those drywall returns are mainly mud and tape. Cut them back, use windows with flanges, insulate from the interior.
Flangeless is the easiest install but IMHO not the "best".
I'm pretty sure the drywall return is not mud - but rather actual sheetrock strips. It is the one of few decent jobs the builder did on the house. Is there any other way to get that foam in without cutting my drywall return? The contractor mentioned drilling holes in the window frame and them covering with caps, but that doesn't sound too good.
Edited 9/25/2008 6:07 pm ET by Will92
Screen molding is like door stop or lattice strips.
If your returns are like most, it's an outside corner bead with drywall returned to the frame, then liberally mudded, taped and caulked. I doubt you'll get the old windows out without damage
how about buying windows with preapplied foam? They are made.
Will92
Aren't there windows with removable fins? Can you not tack the window in place, remove one fin, add foam, replace fin and so on all around the window?
Personally, I would remove the drywall. Even with fins, windows should be shimmed in place and you can't do that with that drywall there. You could then add a channel on the window to return the new drywall to. Easy, but a little time consuming.
Will92,
What happened to the old windows? 18 years seems like a short life. Is this how long windows are supposed to last?
Harold