# Bird Block Soffit replacement options?



## Heather WA (May 5, 2007)

*URGENT* We need to increase the air intake in our attic and currently have visable 3-hole bird block soffits installed under the eaves. Someone suggested we remove several of the bird block sections and replace them with screened soffit vents. We're wondering if these screened soffit vents would work without letting the rain or snow enter the attic? We assume they were probably designed for use under an eave rather than for the kind of opening a removed bird block section would present...

Or any other suggestions for replacing some of the soffits? Would a wooden louvered vent work if we put screen behind it (for insects) and do these even exist in the size to replace a bird block section? 

We'd appreciate ANY ADVICE on how to deal with this situation, as we're desperately needing to increase the intake air flow and don't know what to do. We know adding a ridge vent or attic fan will be almost useless if we have inadequate intake...HELP!!!


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## Ed the Roofer (Jan 27, 2007)

Insert photos of your existing intake construction please.

Also, are you doing any roofing work at the same time or planning to in the near future?

The reason I ask, is that if you were considering that option, then the answers will vary, and probably be more efficient.

Ed


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## Heather WA (May 5, 2007)

*attic ventilation*

Thanks for your reply Ed! I don't have pictures at the moment and I'm not sure how to send them anyway but I'll work on it...For now I'll tell you a bit more what's going on to see if that helps.

We have an 8 yr old, two-story traditional style home located in western Washington state so our weather is not too extreme. The builder used hardiplank siding and (visable) bird block soffits between the rafters installed at a slight downward angle just under the eaves. There are 56 three-holed soffits, with all (but maybe 5) located on the north & south sides of the house. The roof is a 10/12 pitch with composition shingle. It's a tall house & we will not attempt modifying the soffits ourselves. In addition to the bird block soffits, there's a gable vent on the west end, and the east end has a window that opens, but it's in a semi-finished 8x12 attic room so it doesn't open up into the main unfinished attic unless we keep a door open. I'm not aware of any other venting, but the current venting did meet code in 1998. Attic size is about 1400-1450 sq.ft.

There's actually no problem with our existing roofing right now, but we've recently noticed that we have a serious problem with attic (or Cluster) flies. They hibernate in attics all winter and then come out in Spring and hang on the warm & sunny sides of the house, often in clusters. There are hundreds & hundreds & hundreds of them! They're harmless but a huge nuisance and they speck up the siding & windows like crazy. Luckily so far we've only had to catch 5 or 10 in the house each day but we're afraid if we don't do something it will worsen each year. These are not your normal breed of fly in that they emerge out of attics in Spring, fly out to the lawns & fields in summer and are parasitic to earthworms, and then in late August or September they migrate back to a warm & cozy attic to hibernate again until the next Spring. They also hibernate with an extra layer of fat so they don't respond well to bait, and spraying them doesn't do much unless you hit them directly as they don't pick up residual spray on their legs. So after much research a trusted 'pest control' person said the best thing would be to do an attic fog spray in the winter to try to reach some of them, but before then it's imperative this summer that we seal, seal, & seal any cracks or openings where they might be getting in. Upon further inspection of the house, to our horror we realized these flies can zip right through the 1/4" screen mesh that lines all of the bird block soffit holes! We found two ways to reduce the screen size on the soffits, one with either a 1/8" or 1/16" (non-louvered) screened mini-vent from Maurice Franklin Louver Co (mflouverco.com) , or purchase that size in stainless steel screening (or actual bird block replacement screening) from GateLatchUSA.com. But our concern is that by covering the holes with additional screening we will be cutting down the intake air flow to the attic, and we don't want to have roof problems later. We want to use 1/16" screen (as it's true 'insect screening' like window screen) since we worry the flies might still be able to slither through 1/8" screen, but we also know it may cut down even more on air flow.

With all the calculations done for our size attic, it was determined that if we overscreened all the soffits with 1/8" screen, to regain lost air intake flow to reach current amount, we'd need to open up at least four whole soffit sections (2 front & 2 back), or to gain optimum air flow intake, it would be 8 sections (4 front & 4 back). And that's if using 1/8" & we'd really like to use 1/16" screen. We're not even sure if & how the bird block sections can be removed -- and if so, how they'd be re-vented. We bought one 3 x 22 screened replacement vent (nwmetal products.com) from a local builder's store but when put over our soffit section there are gaps at each end large enough for bugs to fly through & too large to caulk so I don't know if that would even work and maybe a custom vent would have to be designed. Then of course we also wondered if rain/snow would get in 3 x 22 screened vents as they're a larger area than bird block holes and although located right under the eave, they're not in a location as protected as 'under the soffit' continuous strip venting. 

So there you have the situation in detail, so you know what we're dealing with. At this time if possible we'd prefer the simplest & least expensive solution to deter the flies. And if there's any way to re-do the soffits without it costing a fortune we'd consider that too, but as for re-roofing we don't really need it now but may soon if we fry the roof with newly screened soffits! We've been losing sleep over this nightmare so if you or anyone else has any advice on how to correct it or deal with eliminating attic flies we'd be so extremely grateful!

THANKS FOR ANY ADVICE!!!!!!!!!

~ Heather


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## Heather WA (May 5, 2007)

P.S. Bad news...Just did an experiment and a fly managed to get through 1/8" screening after only 3 tries! I guess there's no choice other than to use 1/16" screening if we want to reduce the fly population here...  Given our current venting situation, HOW in the world can we compensate for the lost air intake if we add the needed extra screening?! We seriously need advice & would appreciate any help.


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## garyr (Feb 25, 2011)

*heather... ventilation*



Heather WA said:


> P.S. Bad news...Just did an experiment and a fly managed to get through 1/8" screening after only 3 tries! I guess there's no choice other than to use 1/16" screening if we want to reduce the fly population here...  Given our current venting situation, HOW in the world can we compensate for the lost air intake if we add the needed extra screening?! We seriously need advice & would appreciate any help.


heather..... dont know if u have solved ur fly problem but was wondering if there r gable ends ? if so to create more air flow there can be a nice gable vent installed on the gables. this would allow cross ventalation and u could get away with smaller sceen even if it was added to the back of the vent itself... if this option is viable then there r aluminum covers 4 covering the bird blocks under the eaves and smaller screen can be added before the new covers were installed... just a thought) good luck gary i live in arlington wa. if i can help let me know.. :thumbsup: have a great day


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