Your structure has a bad air leak causing the frost and possibly a water leak looking at the left portion of the pic.
Thank you for the comment I appreciate your thoughts and would appreciate some more of them,so here is some more info for youYour structure has a bad air leak causing the frost and possibly a water leak looking at the left portion of the pic.
the frost was there when i pulled off the vapor barrier and the insulation. I should aslo mention that the moisture is above the basement framing (bi-level) and seems to be in the area on top of the basement walls between the floor joists.Was that frost uncovered when you pulled out the insulation--or did it grow after you exposed the cold wall sheeting?
Your structure has a bad air leak causing the frost and possibly a water leak looking at the left portion of the pic.
Thank You oh'mikethere are several insulation/ house sealing pros here---
Let's see if one of them has a remedy.
Thanks for taking the time to ask these questions.1. The frost is on the engineered rim joist only, or on the rim and the top plate below?
The frost is on the rim joist only, none on the top plate
2. Is the p.t. solid wood plate sitting directly on the concrete or is there a poly sill-sealer material between them? Could be wicking moisture from exterior grade; http://www.greenbuildingadvisor.com...ressure-treated-sill-plates-and-building-code
I don't know if the bottom plate has a poly sealer or not, I can't see it wicking from the final grade as the top of the foundation is 16 inches out of the ground
3. How long ago was the house built and did it rain a lot then? Could be wet lumber taking longer to dry between joists- no air movement, temperature difference, etc.
the house is less than a year old, it was not wet when it was built. The homebuilder is all over fixing the problem we are just trying to find the source of the moisture
Tyvek requires taping and sealing for an effective air barrier.
I can't tell its covered by the siding
4. What type of siding?
vinyl
5. Any rain-screen air gap?
sorry don't know what that is
6. The air barrier on the rim joist should be air-tight as mentioned, foamboard/canned c.c.foam is best to stop infiltrating/exfiltrating air movement (either the inside poly is leaking or the outside air barrier (possibly taped sheathing) is));
air barrier on the rim joist is fiberglass covered by plastic. Gonna have to take off the siding to check the outside air barrier
http://www.buildingscience.com/docu...joist/files/bscinfo_408_critical_seal_rev.pdf
http://www.buildingscience.com/documents/digests/bsd-103-understanding-basements?full_view=1
Gary
The house is a bi level, so the bottom course of the siding is well below the area where the moisture is collecting. That said I wouldn't be surprised if it is an exterior seal problem.I see the answer above, vinyl siding.That was my fist thought when reading the thread. You are getting a leak , most likely at the bottom of the wall where the vinyl siding starts.On the exact opposite side of the frost or in the immediate vicinity look up behind the bottom course of siding and you will see the problem.
Not even close.Wouldn't the tyvec stop the wind from entering the home?
on another note,how do you send a pm to somebody here?
+1There is little moisture in cold air, and Alberta air is about as cold as it can get. Thats why I am suggesting that is interior moisture condensing on a cold surface. Exactly the same as the frost forming on the bottom corners of your windows.
+1Just because the house has Tyvek that doesn’t mean it was installed correctly and believe me, sloppy installs happen way more than you’d think. Even if it’s taped there is likely nothing sealing it at the very bottom.
I’d still want to see what the sheathing looks like on the other side of the wall at that spot. That type of inspection would be real easy to do with vinyl. But... with as cold as it is right now you need to be real careful with the siding. It will be very brittle and can break easily.