STUCCO NEWS.NET

Peel and stick rubber tape like protecto-wrap can be folded over the back edge of the window trim, sealing the back of the trim. 6 inch tape is plenty wide for a good overlap by the tar-paper. This works if you didn't wrap the back of the window opening before setting the windows. In this case they didn't wrap the window openings in 1909. If water penetrates the stucco, it run run in behind the window. The idea of putting on a wide glob of caulking around the window after the stucco is done is like closing the barn door after the horse is long gone.

First let me say that your website is great. Thanks for being there and doing what you do.

I built a single story ranch type house addition over this past summer and am getting ready to have it stuccoed which is the first and only subcontractor I will be using on the job. I've talked with two stucco guys so far and am not real confident about either.

The building is fairly large for an addition, 1600 sq. ft. and it is a slab on grade construction with a truss roof. The walls are 2 x 6" framed and the sheeting is 5/8" OSB sheeting. I am ready to wrap the building but I want the stucco to extend down over the bottom edge of the sheeted exterior walls and be parged right onto the exposed concrete wall forms that make up the foundation. In otherwords, the stucco is to run all the way to the ground with no vent at the bottom of the stuccoed OSB.

My concern now, (other than is it ok to parge over the foundation wall like this), is what type of building wrap to use,,, regular tyvek, tyvek stucco wrap, or regular old "breathable" builders felt? The desire to have the stucco be trowel down over the bottom of edge of the OSB wall seems to defeat the purpose and design of the Tyvek Stucco Wrap as the bottom will be sealed and have no place for the intended drainage of the possible condensation build up to exit that the crinkeled Stucco wrap seems to have been designed for.

I guess my question is,,, am I being overly paranoid about sealing up the bottom edge of the OSB right onto the cement foundation wall. (no gaps here). I see this type of installation all the time where the stucco runs right down to the ground and there doesn't seem to be a problem however, I am familiar of homes that had a "Drive-it" application of stucco where the framing rotted out because of lack of drainage and excess buildup of condensation. I thought regular Stucco was more breathable and didn't create much condensation.

I live in Pennsylvania. A moderate, but temperate climate.

Considering I goofed and did not apply the building wrap before putting in my windows, 3' wide regular Tyvek would be my building wrap of choice here as it would be the easiest to install. The Tyvek Stucco Wrap is 5' wide and is an awkward size for my relatively low 8' 6" wall height.

15 lb. felt paper is best for stucco. We usually use two layers. If there is another vapor barrier like house wrap or zip wall (zip wall counts as a water resistent membrane, believe it or not) we put on one layer on top.

Here, plaster stop (casing bead) is drilled with weep holes.

You should always, always leave a drainage gap at the bottom of the wall. The only time we take the stucco down to the grade or past the grade is when someone insists, or historic work where historic appearance is important.

Apart from condensation, stucco is a porous material, like bricks. Water penetrates stucco even if it has been painted. Water trickles downhill and can saturate the bottoms. After years, these bottoms casn fail. We fix a lot of bottoms caused by lack of weep. It is critical to overlap the foundation with tar-paper, or even put on a metal flashing over the joint between the wood framed part of the house and the foundation.

It is a good idea to leave a gap between the OSB and the foundation, other sheets of OSB or whatever.