Does anyone have any ideas about weatherproofing vinyl siding trim mounting blocks? As far as I can tell, these products are essentially a hole in the siding with a decorative cover on top. I cannot find any flashing system available other than using peel and stick under the lower flange and overlapping this over the next course of siding below the block. I don't really like this system since it introduces water behind the siding. Any suggestions?
I was just at the Mid America site this morning (www.tapcoinc.com), and they tout a system that does not require caulk. I just finished what I would consider a typical application: I installed a plastic building wrap, taping all the seams as instructed, then installed the utility blocks taping over the top & side nail flanges. Putting a water diverter as you described is an excellent detail - its a recommended detail in most siding installation manuals, but for the bottom corners of windows in particular.
The whole point of flashing and diverters is to get the water away from the wall where it can fall away. If you already have a weather-resistant barrier in place, I think you're already ahead of the game with the additional diverter.
The building wrap and tape is good for sure but it is a secondary system. My point was how do we keep the water that is collecting in the hole we have cut for the mounting block from going onto the wrap? There is a fair bit of water here and it should be diverted back out over the surface of the siding, not dealt with after the fact in a secondary way. thanks for the input.
I'm not sure where you're building, but it must get a lot of rain!
I've worked with VSI and ATI (Architectural Testing, Inc, 130 Derry Court, York, PA 17402-9405, 717-764-7700, Fax 717-764-4129) in the past on various vinyl siding issues including moisture penetration, and I know both are proponents (as am I) of making sure the wall is weather-resistant prior to siding. I also know ATI has done extensive testing on how far inward wind driven water can go before gravity takes over in a typical vinyl-to-accessory scenerio. I believe I remember them saying a 10" wide secondary flashing placed along an opening is wide enough to keep the water from the wrap completely.
This info probably still doesn't answer your question, but my point is if the wall is properly prepared first, whatever water that should get back there can do no real harm. Let us not forget that water penetration and proper drainage channels involves more than just vinyl, it involves wood, fiber-cement, stucco, EIFS, and even brick.
Good luck on your quest Dave, I'm sure if there's an answer for your question, you'll get it here.
My understanding is that housewraps are air barriers *not water barriers*. I don't see any reference to water barriers on DuPont's site for Tyvek. As I see it, the *beauty* of vinyl siding (if there is such a thing) is it's ability to let water free flow behind it so no water gets encapsulated between the siding and the weatherproof barrier. Vinyl siding is a rain screen. It would seem that 30# felt would be a more appropriate weatherproof barrier than an air barrier.
It depends on the housewrap. Let's face it, Tyvec's whole advertising campaign is based on keeping water out. For a more serious approach on barriers, this review by the University of Massachusetts does a good job: http://www.umass.edu/bmatwt/publications/articles/housewraps_feltpaper_weather_penetration_barriers. html
All sidings are simply another defense for your home to keep water out. For the record, I've always built with 15# felt behind vinyl siding - 30# felt, once its cycled a few times, can effect the level of cheaper sidings (which I never use!).