proper window installation

[lelson]

I have a window that was installed in a stucco wall years ago that leaked. When the stucco was torn away around the window today, the contractor said it leaked because the tar paper was installed wrong. It went in front of the metal fin rather than behind it, according to him. (It also was installed poorly with numerous tears and not much coverage of the metal fin) Is he corrrect? Should the tar paper go behind the metal? Seems like the metal would be left to rust that way.

[robson]

tarpaper - or by todays standards tywrap, first - then the window, siding then caulking

[I R Baboon]

negative batman. tyvek, caulk the window flange, install the window, seal entire nailing flange with window tape (flexseal flexwrap whatever its called) then siding then caulking. the only part of the tyvek that overlaps the flange would be the top.

[Lil' Dave]

Can't imagine tearing away a stucco wall and the metal mesh without damaging the "tar" paper.

Don't know about tar or felt paper. We always used something the boss called moist stop. Black and rubbery, somewhat shiny, no line markings on it. Came in rolled sheets about 3 foot wide. This was laid in the window stool, edges cut just enough so the remainder would drape below the window. Any other additional covering for water or vapor covered that.

Seen similar lately but has adhesive backing, and is not nearly as wide. This is sorf of like tape. Procedure is to lay a band across the bottom, then both sides, then the top. Water can't get under it when traveling downwards this way. You should still lay some form of moist stop on the stool first.

[Warren Block]

Jeld-Wen has a PDF of installation instructions that seems to be very thorough. Look on page 4:

[Colbyt]

To answer your question YES he is right.

As others have pointed out there is more to a proper install than that. But there is no way it could be considered marginally correct if the paper was over the fin.

[Steven]

You are exactly right. Before all of this flashing tape came out, we would cut 30# felt into 12" strips and tack around the window. Our procedure was felt paper on the sheathing, moist stop on the sill, bead of caulk on the back of the nailing fin, window installed, nail through every hole in nail fin with 2" roofing nails, strip of 30# felt tacked across the bottom, strip tacked up each side (overlapping bottom piece), strip tacked across top (with sheathing felt rolled back down over the top piece. Now, we use the flashing tape and tyvek in lieu of the felt paper. I actually prefer the felt, but the flashing tape won't stick to it worth a damn. An unfortunate common misconception is that the nailing fin is flashing. What robson described, though practiced daily by most framers, is grossly incorrect.

Just my .02

S.

[Colbyt]

Steven,

The (I may mis spell this) Protecowrap product will stick to the felt just fine. Place it and roll with a J-roller. It seems like it isn't sticking. Two days of sunshine and you can not remove it.

OTH, it does not seem to stick quite as well to the Tyverk product. It does but not as well.

[Steven]

I may have to try that. I'm not completely sold on housewrap. Not much can beat felt. I've pulled off siding that has been on for 40 yrs, and the felt behind it looked as good as new. Time will tell if the housewrap is as durable.

S.

[Bob Morrison]

The purpose of the housewrap is to let the house breathe while preventing water intrusion. Sort of like "Gore-tex" for houses. Felt will trap water vapor inside the house, making your insulation less effective.