Building out rainscreen for siding on 2" rigid foam, and for roof. My question is, is how do I stop bugs from going in these spaces?? I have horizontal 8' 1x3 strapping, but if I put the first row build out, it still leaves me a 3/4" gap.. Went to ABC supply, and they guy said he had nothing for this problem.. which I highly doubt.. Does anyone have product names?? I don't wanna wrap bug screen around.. but that may be my only choice..

Also, for the roof, if the Vented OSB assembly above the foam, how does one actually let air circulate thru? I can understand the gable vents, but when I look at roof detail examples, I see people just using a wider/longer flashing, going from vented OSB straight down to existing Facia board.. But if the flashing is there, how does any air vent? Don't want bug screen as it can drip and wick right up under the OSB.. Any Product names or ideas for that?

Anything examples/products are appreciated!
Thanks,
Tom
Sterling, VA

EDIT

http://www.cor-a-vent.com/

Found this product? Any one use this stuff before?

Look up Cor-A Vent products- they specialize in all that stuff.

Edit- missed you edit. I believe it's widely used.

I used the PS-400, cost about $84 for 48 4' sticks, also from ABC.

Hi Tom;

We design rain screen walls using Eternit and Parklex facade panels using galvanized steel subgirts but we use vent screens at the top and bottom to keep bugs and birds out of the ventilated cavity. In the past we have used 26ga galv wire mesh 1/4" x1/4" bent up in the shape of an "L" or a "J ". Any local sheet metal contractor with a suitable bending brake should be able to make you a vent screen. We usually fabricate ours in 10 foot lengths.

A simple L shape would probably work best for you, installed at the bottom and top of your furring strips. Make the long leg of the L about 3 inches and the short leg the same as the thickness of the furring strip. Then install your panels over top of the furring strips being careful that the vent screen does not put any pressure on the panels.

Recently we have gone to using black painted custom perforated aluminum vent screens because they offer advantages over galvanized wire in installation. One reason we are using the thin aluminum is the reduction of "buildup" in local areas caused by many layers of vapour and weather barrier and flashing. These buildups can put pressure on our FC panels after the fasteners are installed and if not planned out can cause the panels to crack.

The black color blends in with flashings and there is no corrosion or rusting from the galvanized wire. Be careful with who you buy galvanized wire from, much of it comes from China and their companies have a special grade of galvanized steel that rusts ! Try to source USA made galvanized wire if possible.

If you need to discuss further or need a sketch of the vent screens, I can send you a pdf , just call me at 905-467-0233

Hope this helps

Adrian  Dunevein
AAA Drafting Services

Thanks very much. I didn't even thing about braking Perforated stock into a J channel. This is what I'm going to try for.. or maybe a heavier gauge wire mesh stock so its brakeable. Thanks! Tom

Try using what roofers use in ridge vents to keep out the bugs... it's a black mesh material. It's durable, it vents and it will keep out bugs/birds.

There is an interesting video on this subject here:
http://www.greenbuildingadvisor.com/new-videos-greenbuildingadvisorcom

The video is toward the bottom of the page.