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where does the housewrap go????

toolbabe's picture



If you're installing an " outie" window which is in the same plane as the back of the siding is it best to apply the housewrap over the rigid foam? or vice versa! My windows are small sliders that have a nailing flange.

sheathing/housewrap/foam? or sheathing/foam/housewrap? then the vinyl siding.


When it comes to windows and exterior doors is it code to apply some type of flashing (moisture proof membrane) over the sill, jams and head of the window? or is the use of these peel and stick membranes optional?

specially with vinyl, (post #211793, reply #1 of 3)

specially with vinyl, flashing is critical. if they are not flashing properly stop them. you will have rot beyond your imagination very soon if not.

a drip cap, house wrap and window wrap are a must in your situation.

HI Mark, ok so you're (post #211793, reply #2 of 3)

HI Mark,

ok so you're saying It's not exceptable to just wrap the housewrap inside the jams and over the sill the way my carpenter did. I know you can install the housewrap 1st and then apply the membrane. Or you can  apply the membrane and then the housewrap. some people say intalling the housewrap  first is the way to go.


from looking at the window installation from the inside and outside I don't think he used a membrane. Judging by how the exterior door was installed I don't think he used any flashing membrane on the windows. Maybe he thinks using spray in  foam is all that's needed to keep moisture out.  What in the name of god is that styrofoam looking stuff nailed on over the housewrap. What's with that?? What purpose is that serving?  I assume he'll put a drip cap on when he goes to install the vinyl siding.

I don't want to tell this man how to do his job.. I guess without removing the windows I'll never know if he flashed those windows unless I ask him..


If the windows aren't installed per the manufacturer's instructions then the warranty will be void. that much I do know.


Is there anything else I should be aware of with regards to the window installation. What can you decipher from the pics?


I'm going to need to discuss any deficiencies with the carpenter so the more information I have at my disposal the better. or else he's just going to tell me the window has been installed correctly and without the building code it's going to be hard for me to make a good argument as to why I think those windows aren't installed properly..   I need to be briefed on window installation.


Things are not going well with this reno.




Hi Mark,    I was just (post #211793, reply #3 of 3)

Hi Mark,


 I was just watching a video on Utube on how to install Tyvek over rigid foam. I noticed that they placed a strip of peel and stick membrane over the area where the sill meets the concrete foundation wall. Then a strip of metal flashing was applied over that and nailed into the bottom edge of the sill plate.  That's probably what I need otherwise water is likely to find it's way in around the sill plate leading to rot down the road.  Taping the bottom edges of the housewrap onto the concrete and then nailing foam over that without attaching any flashing isn't  going to cut it is it?????? water has already gotten under the tape and it's beginning to lift off . without any  flashing that water is likely to do some damnage. That water needs to be directed away from the sill plate.. Hard to know what's under that styrofoam.

Still waiting for the vinyl to come in. It's been  3wks now.