Wall layers and moisture management
Hello,
I live in Houston, climate 2, 1980’s brick veneer single story house with hardy cement siding above the house . I have been dealing with an ongoing moisture issue throughout the house which led me to remove the drywall in my unconditioned attached garage wall. Behind the drywall there is old partially damp Buffalo board used as sheathing, behind the buffalo board is the back side of the homes exterior brick. There is unfilled brick joints and there’s a lot of overfilled mortar that isn’t giving a 1 inch space between both layers and is in contact with the buffalo sheathing .
Above the brick, you see the attic wood framing at the top plate , and DuPonts house wrap over the attic wood studs and over the front of the top layer of bricks . I’m just going to call it Tyvek from here on after.
Im unsure . Should I fill in the unfilled brick joints with mortar/caulk etc or don’t ? Should I seal the brick with a waterproofer from behind to help with moisture control? I do plan on chiseling off the excess mortar and replacing the Buffalo sheathing with OSB.
Now , the tyvek placement has me confused , the top exterior portion of house has hardy cement siding , and tyvek behind it and over the top framing of the house which is the attic wood studs , no sheathing at all. Shouldn’t the tyvek be behind the brick and over the sheathing normally ? So in my case since I don’t have sheathing , when it rains, water runs down the tyvek onto the brick im assuming , is it ok the way it is? This has me confused. Is there anything I can do from inside the wall to help with water vapor in the air coming in? Is it too late to add a moisture barrier somewhere? Sheathing on the inside of the wooden frame studs? Redoing the exterior is not an option since I had it replaced about a year ago when I didn’t have the knowledge that I do now . Also no air gap behind the tyvek , just nailed on over the attic wood studs. . Also my attic is a vented attic if it matters. I added some pictures of garage wall and a pic of attic so ya can get an idea . Thanks I’ll appreciate any advice.
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Replies
Some questions:
1. "With hardy cement siding above the house" - Do you mean you have Hardie siding on the gable ends at the attic level?
2. You have moisture issues in the house yet you removed the gyp in the garage. Is this because the garage is an aesthetically acceptable place to remove gyp, and you did this so you can see see the details of the construction? Or something else? If the main issue here is that you are trying to solve moisture issues in the house, can you please describe those issues?
Brick - Don't worry about "unfilled" joints if they are as you show in the photo. It's not the best masonry work, but it is fairly standard. Also, don't worry about not having a full 1" between the back of the brick and the face of the sheathing - as long as there are some gaps - and from your photo it looks like there are - there is enough space for water to drain down.
3. What do you mean by " and DuPonts house wrap over the attic wood studs and over the front of the top layer of bricks."?? I understand the house wrap is apparently applied directly to the framing, but I don't understand what you mean by "over the front of the top layer of bricks." The attic gable end framing should ideally have sheathing on it, and the house wrap should be attached to the sheathing. The second photo you posted appears to be taken from the inside, in an unconditioned attic. The house wrap appears to be applied unusually well - punctures taped, and applied tightly. Are you sure there is not a layer of sheating on the outside of the house wrap (ie perhaps it was applied as a temporary barrier after the original sheathing was removed, then sheathing applied on top of it? - the framing indicates this is an old house - maybe from the 1920's or 1930s?)
4. "Now , the tyvek placement has me confused , the top exterior portion of house has hardy cement siding , and tyvek behind it and over the top framing of the house which is the attic wood studs , no sheathing at all."
Yes, the layer from inside out in the attic should be framing (as you have), sheathing (which appears to be missing and is typically needed for structural integrity), house wrap as you have (unless the sheathing is zip), a rain screen (to create a gap between the face of the house wrap and the back side of the Hardie, unless your house wrap is the dimpled type), and then your siding.
5."Shouldn’t the tyvek be behind the brick and over the sheathing normally ?"
Yes, but your photos showing the back side of the brick look like there is some sort of sheathing behind the brick and based on the looks of your attic framing, if the brick is original, your brick was probably installed long before house wrap existed.
6. " So in my case since I don’t have sheathing , when it rains, water runs down the tyvek onto the brick im assuming , is it ok the way it is?"
Based on your photos there is no house wrap at the main level behind the brick, only above the brick at the gable ends. So it really depends upon both how the house wrap was terminated where your finish transitions from Hardie to brick, and if the brick has weeps at the base.
7. "Is there anything I can do from inside the wall to help with water vapor in the air coming in?"
Are you asking this about the attic? If the attic is unconditioned, you should have outside air coming in the soffits, so vapor permeability is not really an issue.
8. "Is it too late to add a moisture barrier somewhere? Sheathing on the inside of the wooden frame studs?" Are you asking about the attic? And do you mean moisture or vapor barrier? Your siding should be your bulk water barrier. Sheathing is not a moisture barrier. It is however needed for structural stability.
9. "Redoing the exterior is not an option since I had it replaced about a year ago when I didn’t have the knowledge that I do now ."
You had both new brick and new Hardy installed? Was the work permitted and inspected?
10. "Also no air gap behind the tyvek , just nailed on over the attic wood studs."
There is not supposed to be an air gap behind the tyvek. It attaches directly to sheathing.
11. "Also my attic is a vented attic if it matters. "
Thanks - clarification appreciated and taken into account in above responses.