House is currently under construction, brick veneer, aspenite-type sheathing, 2X6, fibreglass batt insulation. Southern Ontario Canada. The whole house is Tyveked, except for the garage, which has fibreglass batt insulation, and will be unheated, except for the radiant- floor-heated loft above it which has Tyvek around it.
My question – shouldn’t Tyvek be put over the aspenite around the garage whether the garage is heated or not? The Tyvek is an air barrier, but I would also expect that it would protect the aspenite from moisture behind the brick. I would expect that a poly vapour barrier on the INSIDE would be uneccesary but I would think that the Tyvek on the outside should be used.
Well, what would YOU do, fine homebuilders?
Regards – Brian.
Replies
Tyvek is not much of a moisture barrier which is what you need behind the brick. Water will pas through the brick so two things MUST BE DONE to prevent that water from damaging your home.
Ther must be open weep holes at the base of the brick veneer to let water drain out.
There must be tarpaper on the framed wall to keep the moisture in the void from entering the house and/or causing mold to eat the house.
Excellence is its own reward!
Piffin - would I be correct in concluding then that the Tyvek over the rest of the house is inadequate to protect the OSB sheathing from moisture damage? In my view, moisture would stay on the outside and run down the Tyvek without penetrating it. Everybody uses Tyvek this way in my area. Any moisture that does get through or has condensed on the interior of the wall has the ability to dry to the exterior through the Tyvek. Is this a missapplication of the Tyvek or is it Tyvek in general which you don't think is sufficient for any application?
Ah... weep holes. I haven't seen a recently-built house yet where the weepers were all open, by any builder. Six months ago I took a flashlight and went around looking at houses for this. I'm presently fashioning some devices to prevent the mortar droppings from blocking these, as Mortar Nets are an exclusive product only for the rich and famous. It's a situation where once the weepers are plugged, there's darn near nothing you can do to open them without risking compromising the (Tyvek) membrane behind, a danger much worse than leaving them blocked up. At most, the bricklayer will tool the opening about halfway through the thickness of the brick, which makes it APPEAR as though they are open, but rarely can you see all the way through to the sheathing/ membrane.
Regards - Brian.
Agreed.
Have not seen working weep holes in residential work since, maybe, the sixties?
Tyvek should be fine as a barrier behind brick veneer. I've used both 15# felt and Tyvek. Supposedly Tyvek "breathes", but I've also used it as a canopy to cover material in a heavy rain with no penetration. Canvas tenting breathes but also repels liquids just fine.
I'd be more comfortablw if at least the bottom 18" of wall sheathing were covered with tarpaper.
I feel like from what I have seen that Tyvek is OK where the water is allowed to keep draining. siding stops at the bottom up off the ground so it can drip free.
But with brick veneer, the water will stop at the base and pile up if no weeps are provided. Cotton clothesline makes a fine wick even if left in place. I don't see brick homes here but i remember out west that the bricklayers laid in the scrap of cotton line and pulled it out later.
There's been lots of industry notice of lawsuits over mold because of barriers and weeps neglected.
Excellence is its own reward!
I was project coordinator on a job a few years ago where brick weep holes, mortar droppings, and cavity ventilation were all big issues with the archy.
They specified a peel and stick flashing that was 24" wide. It was folded so the bottom course of brick was laid on it, and the remaining 18-20" provided the wall flashing. Bricklayers liked the stuff.
Weep holes and ventilation were provided by inserting a plastic weep/vent device in the head joints of the bottom course, above and below windows, and just below the frieze board at the top. Bricklayers did not mind them, but had a heck of a time remembering to put them in all the correct locations.
Mortar droppings were controled by hanging a 1x4 with eye hooks and cord from the brick ties and pulling it up and out when that row of ties was reached. That was every 16" because the wall was block and the DuraWall reinforcement with integral ties was at that spacing. They also added 2" rigid foam insulation to the block wall as they went up. All in all they bricklayers hated this aspect of the job, but it accomplished the goal of keeping the cavity pretty clear of droppings.
Lintals at the door and window heads were also flashed with the peel and stick membrane.
This was a commercial job with a flat BUR, and before the edge flashing was installed we got a Texas tiurd washer of a rain. To my relief and the bricklayers, all that extra stuff they had to do worked. Every weep hole had water drain out of it!
All things considered I would opt for the cotton rope weep Piffen mentioned, use the peel and stick fashing beneath the bottom course and up the wall, and pay the extra labor for the 1x4 cleanout trick for the mortar droppings or purchase the matt material designed for mortar droppings.
Dave
Out here, when ever I have seen a mason doing brick work there has always been weep holes in the bottom course.
Wouldn't it be most unadvisable to leave them out?
But then again,
Drywall in a sauna, granite tile counter directly over laminate, thicker SR so tile will lay flush with no mortar in back of it......etc etc etc....View ImageGo Jayhawks..............Next Year and daaa. Blues View Image
JLC had an article a yuear ago about somew builder in the mid west who had hundreds of lawsuits starting agin him because no weeps. Photos showed lots of mold in an openned wall.
Joe Listibrck probably has some on his building science website too.
Excellence is its own reward!
CAG - Take a flashlight and look inside the weepers to see if you can see to the sheathing or its covering. 'Bet there are lots that aren't open. Maybe I'm a whiner (weeper) that my weepers might be blocked - at least when I'm compared to someone who's house doesn't have any weep openings at all!
The Tyvek on my house is well sealed with a synthetic "tar"where it meets the brick ledge, coved in a radius so moisture accumulating at the bottom is channeled away and shouldn't remain in contact with the bottom of the sheathing (as long as the weep holes are open).
BTW - I will be placing (stuffing) nylon stocking pieces in the weep holes to prevent insects (wasps, ants, spiders,etc.) from entering the space easily. My wife has been saving them for this. Should allow air and water in and out, might slow drying a bit, but other than that anyone know any reason NOT to try this?
Epilogue to this thread -
As it turns out, the masons will be installing ther own "construction paper" ( I assume tar paper) behind the brick over the lower unheated, but insulated garage when they begin working. Must be cheaper than the Tyvek used over the rest of the house.
Thanks for the info - Brian.
Don't assume it is tarpaper. building paper is red resin paper and was once used behind lap siding. But it is not water proof..
Excellence is its own reward!
Thanks Piff - I'll check that out.
Regards - Brian.