I get these caps made local for 55 bucks and charge 120 installed if I can walk up to it , I've never had a problem with it but there could be a better

I do the same thing,and sometimes paint them to match the roof, you can't see them from the ground. That one looks to be well made. We bought a 36" brake and mounted it in the shop so we can now make our own,and we keep a couple of the common sizes in stock.

Ya he keeps a doz made ready for me and one other guy , for what that wire cost does it save money to make your Owen

For those who remember Kirk Lapierre he did a youtube video on this.
http://kirklapierre.com/videos/how-to-make-a-ventilator-cover-kirk-lapierre-video/

I do them from the inside and have never had a complaint. Everyone says squirrels will nest on the wire but I think the fact that raccoons can get in those nests, prevents it. The raccoons can also reach in and feel my wire and then go to the next house.

Paul, I've seen three different burnt out fan motors from exactly that method. Fortunately they were homeowner or handyman done and not by me.

HY-C makes a good power roof vent guard. Doug fields also has some nice vent covers and other products.

http://fieldsdevsupply.com/

X2

David, what would make the motors burn out if the screen is on the inside vs. outside?

Inside is nice. But the photos look good too!

David, why the burn-out?

WWhen a squirrel makes a nest on the mesh, the fan can get stuck causing the moter to overheat and burn out. Is what David is talking about I believe.

Yep, a fan full of leaves can't turn. I was honestly surprised not to find fire damage.

NWCOA did research on this I herd claiming we were burning down houses , NWCOA said to stop putting on the inside because squirrel and birds were nesting on it , witch caused the motor to burn , attic is not a good place for fire , I know I see we're past company's were doing this there's straw and strings hanging down a few feet . I thought everybody had stopped . It doesn't seem to hold up very good ether . I get my insurance from NWCOA so I should follow what there trying to tell me , I fig someone was taking the hood off and had some cool way of rigging something then putting it back on , well any way if your still doing please stop

Around here, I have found that most of the fans don’t work in the first place. Of those that do work, if screen were placed on the inside, any leaves above them would make them useless anyway. I usually replaced the original screen with very heavy-duty mesh; invisible and the fan still serves its purpose.

How do you secure the top of the heavy duty mess

Ron, that would be ideal. If you could explain how it would be greatly appreciated.
I see that older models would come with either quarter inch hardware cloth or similar sized expanded metal lath, usually firmly secured. Anything new today has at best plastic screening and fiberglass screen seems to be the norm.

X2

Around here they have a temp gauge on them , people tell me all the time they don't work , what they don't know is there temp.activated , I'm sure you guys know this because the attic fans are more common in the south ,they must just be old and worn out

Plastic topped attic fan gets a HY-C RVG3030 since an excluded critter WILL destroy the top to get back in if I just do a screen replacement. Metal top gets either the HY-C rig or a 1/3rd inch stainless mesh refit that mates closely with the underside of the top (customer's choice). I've seen too many nests in fans either with or without somebody screening from below. I don't want to be the one they point the finger at if the place burns down, so I never screen from below on a motorized vent. Static vents, that's a different story.

Take the cover off, use quality 1/2 by 1 " hardware cloth and make a circle around the fan fixture, cut down to the top of the brackets and fold down over the top of fan, cut off anything in the way, use self tapping screws and secure the top back over the fan fixture. Never took pictures, sorry.
Cover over top has many advantages and can be removed and work performed on fan.
A few months ago I revisited a customer on an unrelated issue and notice a fan cover resting on the chimney and asked the customer what was going on and how did the cover get there. Turned out that They had a new roof and the roofers put it there and forgot to reinstall.

Always have screened from outside. Once RVGs were available they were much quicker. And that is one reason we only install roof vent guards. By the time I mess around with making a cover or screening I can put on a number of RVGs so there would be no cost savings for customer. Don't even want wildlife to get a hold of vents, even if they don't make entry the possible water intrusion is an issue. And the possibility of a fire or burning out motor seems to be a real possibility and not one I would want to gamble on. Same reason we don't screen or put bird guards on dryer vents only Heartland dryer vent covers.

I do what LAtrapper and that proline guy do. The only thing I might add to Tim's instructions is I put the 1/2 by 1 hole horizontal. It give more wires to push over adding strength. I do believe it is impossible to push over either way without totally destroying the cover first.

Between the time I started typing and posting Charles out typed me. The first vent with the 1 by 1 wire is what I have done with a heavy gauge 1/2 by 1 wire. The 1 by 1 seems to have held up but the animal removed the cover. I have never had that happen I don't know if it was improperly re-installed or if it was a flimsy built cover but I will remember that picture when I make a decision on my next cover.
Charles was the second vent with the top totally gone also a large attic vent. It looks like one of those smaller attic vents that I think you would definitely put a hy-c or a sceen like Pesky used on the smaller vents. If it was a larger vent also I will probably quit taking the vent apart and applying the 1/2 by 1. It is not any cheaper I have always given both as an option to the customer and many have chosen the enternal screen for aesstec because it looked better.

I don't understand the power vent and ridge vent on the same roof side by side. Seems they could live without the power vent.

More Photo's are Needed... Like Vinke says!!!

Everyone knows what they themselves mean when they type out "what they do"... some of Us are Visual learners (its an actual term... LOL!

Power Vent near Ridge vent looks like a re-roof and the ridge vent was added. I have seen may co-mingled venting systems on houses after a re-roof.

Charles, like the pictures

I have seen many motor burn-outs but none caused by anything other than raccoons twisting the blades. It's almost like they know if they don't shut the motor down permanently, eventually it will get hot and those fan blades will start spinning again.

Paul B, static vent in picture is sister to vent that was pulled apart and a very common entry point when they are this brand in our service area. The Roof Louver type tend not to be a problem except if squirrels gain entry somewhere on home then they chew out of them. Only picture I have of Roof Louvre entry and it is 5 years old they just are not commonly entered here.

A Builders in our area is putting up to 6 "power roof vents" on a home. Only one will have a motor the rest are just the hoods. Makes no sense to me. But I know for sure I can put up 32 foot ladder install 6 30x30 RVGs put up tools and ladder and complete invoice in less than 50 minutes.

Same roof as power roof vent that was entered. This female coon also entered a louvre vent on home. Roof had only been on for about 9 months, customer called around midnight hearing entry and this is what we found next morning, needless to say customer wanted coon dead!

I'm appalled, but not surprised.

I'm with Kevin and Tim, but I never screen the inside; if there's a fan, it can be ganked by nest material, and static vents will just be useless if full of nest.

Charles, good shots, especially of the brown louvered aluminum vent. As cheap and thin as they are, I've only seen one that's ever been entered!

Looking at this makes me think if I added a second piece of wire to the top would sucure the top edge , I'm going to try it on thIs bat job today

What I use.

I excluded attic fans with covers like this for about 10 years (I made the covers myself, a 36" metal brake from harbor freight is worth its weight in gold). However more recently i have started doing it a different way.

1 take off the dome top
2 use 1X1/2 stiff wire, and make a ring that will fit to the round framework of the unit ( sometimes you have to trim this to fit around the upright mounting pieces, sometime you dont)
3 make sure this piece will not interfere with the fan or impede replacing the dome
4 cut a round piece of wire the aprx size of the ring and hog ring it into place
5 secure with screws and washers ( make sure any protruding screws will not interfere with fan)
6 replace dome

It only takes about $5 worth of mesh, and it only takes about 15 minutes. ( the first couple i did this way took a little longer)
I charge the same price i used to and my investment is a fraction due to less material, to me its a better repair because you cant see it , homeowners like that.

we all know there are too many variations in attic fans to list, so each of these style repairs will be a little different, heighth, diameter, mounting brackets etc. i tried to make these in advance at the shop but due to the variations in attic fans it ended up being just as fast to custom make them onsight. for what ever reason this style repair will not work onabout 1 out of every 30 or so fans.

I got several PM's asking for pics of how i exclude an attic fan as described earlier. so here we go. Please forgive poor photo quallity, it was a crazy steep 2.5 story roof so i was on a chicken ladder, and took pics with my cell phone. Start by taking dome off of fan.
Install riser of wire.

install top to riser

use plenty of stanley rings


replace dome and your done now go collect $149 from home owner.

http://www.broan.com/display/router.asp?ProductID=100673

I cant believe people are still using those electricity-hogs,
This is another option, they are expensive initially,but they will thank you when they see their
electricity-bill drop like a rock,, and it comes critter-proof with screen already installed
(for those folks that may want a "greener" option)
Easy to install yourself,or get teamed-up with a local contractor to install as a sub on the job.
People will buy into this solar-stuff if presented properly,
Jus sayin,,

I like the Pictures trapper4hire

Yes that is nice and was kinda what I was looking for , I've been doing that on my bat jobs latly , with 1/4"