Replies

1. 
   G.LaLonde | Mar 26, 1999 07:17pm | #1

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   Frank, I think you've got the right idea! I'd flash around the windows first with your product of choice and then weave into it with the paper as you go up. I personally always use 30# felt under brick. It doesn't add much to the overall cost and it takes the abuse of brick laying much better than the 15#.

2. 
   Guest_ | Mar 26, 1999 08:01pm | #2

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   Frank:

   Not sure I'm qualified to answer your questions, I'm pretty much a similar situation as you, only about 2 months behind. I've done a fair amount of research on the topic though.

   You did not say what type of windows you are using. You said "nailing flange" which tells me they are not wood windows, so probably either clad windows or vinyl windows. I have been having a hard time making up my mind on what type of windows to use on the custom house I'm building. I want maintenance free, but still want the look of brick mold, to go with the traditional style and the brick home.

   At a minimum, you may want to think about installing drip-cap flashing on top of the windows and doors. This drip-cap flashing should extend up underneath the builders felt. On the other hand, you did not say if it was a tract home or custom, the former of which might limit your options.

   Most windows come with installation instructions - which it would seem reasonable to follow. Either way, I think your framer is at least quality minded considering his intention to seal the windows with caulk.

   I have read the installation instructions for 3 different brands of vinyl windows that we have installed on our Habitat for Humanity houses and they all specified some type of flashing. One called for caulking. The others did not. It would seem to me that vinyl windows need some room to expand & contract. If I were going to caulk, I'd use silicone, since it is 2 or 3 times as flexible as most other types of caulk.

   In a FHB article http://www.taunton.com/fh/features/materials/17caulkvinyl.htm they address some of your questions.

   One window option that I am investigating is high performance vinyl windows with vinyl brick mold that snaps on over the nailing flange. If I go with these, I was thinking about installing a strip of mud sill seal (it comes in rolls) around the window before the window is set, pretty much like a weather strip. This would allow the window to move, act as a air infiltration seal, and offer some water resistance since the poly foam sill seal is not effected by water. On the other hand, I don't see how the mitered vinyl brick mold corners could look good when cold and contracted - read gaps! Whatever route I go, there will be some kind of flashing around the top and sides of the windows.

   There was another FHB article about a year ago called "Common Flashing Errors" (or something similar) that detailed one method for weather sealing around windows.

   Another thought is that most builders in my area wrap the window/door openings with 12" side poly prior to window installation. In a previous thread on this board, the effectiveness of this poly wrap was questioned, but it I think it has obvious advantages, although, once again, the poly needs to extend up under the house-wrap or builders felt at the top of the openings.

   I've gota go now to meet with a prospective framer…

1. 
   Guest_ | Mar 27, 1999 04:41am | #3

   *This ground has been well trodden by heads wiser than mine. Searching the archives will bring up the debates. For my own 1¢ (when I have more experience I'll go for 2¢) avoid poly and use bituminous membrane in 9" strips to wrap the openings. It is self-healing and flexible, plus will enjoy a longer lifespan than poly. When wrapping the opening, "think like water" -- imagine every possible assault (the rain will) and think about where that water will go. Don't rely on caulk and it won't let you down! I also fill with low-expansion foam bewteen the splines and window, another water barrier.Thallon's book Graphic Guide to Frame Construction has a long and thoughtful treatment of window sealing worth considering. An example (per the reviewer's fair use exception to the Copyright Act, so there nitpickers!).

1. 
   Guest_ | Mar 27, 1999 05:53pm | #4

   *Frank, here in MI, we don't do anything special when installing the windows in a brick veneer wall. We do cover the osb, but cut the paper flush around the opening. The use of flashing is not needed because of the brick. The header provides a 3" soffit that acts as a roof. It provides a very good furface to caulk to. Leave the recommended 1/4" gap, and the sealant will work fine. Remember to paint first, thus providing the waterproof seal that you desire.The sides of the window will also provide a good angle for caulking.The bottom should have a sloped sill, and will shed the wate nicely.Water does not penetrate past a window properly set into brick, and caulked properly.Blue

3. 
   G.LaLonde | Mar 27, 1999 07:29pm | #5

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   Blue, One of us is not reading Frank's post right...It sound to me like they are planning to set the window in caulk on bare OSB and then tarpaper around the window as they go up with the brick. Surely you're not suggesting he do that??? There are lots of opportunities down the road for water to leak between brick and the edge of a window and you must be certain that if it does leak, there is a drain membrane of some type under the window to channel the water away from the OSB.

4. 
   Guest_ | Mar 27, 1999 07:38pm | #6

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   I'm suggesting that the water will not enter the wall and all the methods to channel the water are silly, faulty, and unnecessary!

   45,000,000 windows in MI are proof!

   Use a quality sealant, and maintain the waterproof skin, and you won't need 55 layers of waterproofing "just in case"!

   When the water breaks the seal and penetrates the exterior skin, it will ruin the window first!, no matter how hard you try to "channel" it safely!

   I can't believe how redundant the mentality of the "fine homme building crowd is"!

   Put your house in a water proof bubble if you really want to be safe!

   And NO, we don't set the window in caulking either. We JUst nail it to the 15# felted osb!

   Where will your supposedldy better flashing empty the water, out past the brick ?

   If not, it will freeze up, and pop the base of the brick in cold climates!

   I repeat, well maintained waterproof exterior is all you need!

   Siding is different, and will require a head flashing only!

   Blue

1. 
   Guest_ | Mar 27, 1999 07:43pm | #7

   *Frank, put the felt first, and weave, but if your exterior seal fails, the water will penetrate the backside of the window, and ruin it.Take the 10 minutes each year, and recaulk, with a compatible caulk, all the weak areas the might need a touch up.After 50 years, you will be so old, that you won't care if the windows rot out and fall!Blue

5. 
   G.LaLonde | Mar 27, 1999 10:17pm | #8

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   Blue, All I was saying is that he should make sure that there is some type of water shedding barrier UNDER the window BEFORE he puts it in. Then he can weave into that as he goes up with the brick and tarpaper. Sounds to me like you agree by your other post right???? My other point is that you should never depend on caulking as your last line of defense against water penetration. Sooner or later because of poor installation, normal deterioration or no maintenance it will fail!

6. 
   Guest_ | Mar 28, 1999 08:58am | #9

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   Thank you all for the responses.

   Blue, I was wondering about the 10 min. caulking time and carrying/climbing the ladder. Then it hit me, the sashes come out, so you caulk while standing inside the house. (except for the picture window).

   Thanks again,
   Frank

1. 
   Guest_ | Mar 28, 1999 03:16pm | #11

   *G. Lalonde, I'm trying to tell you that the caulking is the only line of defense.The reason that the paper should be put on first, is that the masons will not cut the paper close enough to the window, thus exposing a few inches of bare osb to possible condensation rot.Blue

7. 
   Guest_ | Mar 28, 1999 03:16pm | #10

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   My house is sheated with OSB and will be brick veneer on the outside. The framer will set the windows and exterior doors, and the brick mason will cover the OSB with 15# felt as he installs the brick. My framer's method is to caulk the window flanges (sides & top, not bottom) and install the windows.
   Do I need to add additional flashing to the window jambs? Should I install some 15# felt around the openings before the windows for the mason to weave into? Should I close my eyes and hope for the best? I just do not want to have the loose window/rotted OSB board that I have heard about here in Northern VA.
   I will not be using brick molding over the nailing flanges, just brick. This is quite common here, probably due to eliminating another thing to paint.

   P.S. I just saw another townhouse development with vinyl siding going directly over OSB sheating and no obvious (from 50 feet away) flashing around windows.

   Frank