7 posts / 0 new
Last post
Rich73Kelly
Installing roof vent

Hi all,
I submitted this in the "Roofing" section, I want to post it here too.
A couple years back I bought a vent to install on our garage roof as it gets quite hot in there during the summer. The vent has like a 10" hole in it. The garage is 24'x 24'. The roof has a center peak and slopes on all 4 sides.
Which side do I want to put this on? Which way should the opening face ? How far down from the peak ? Does common wind direction matter ? :confused:

Rich Kelly

JacktheShack
Re: Installing roof vent

Some of these sites deal with hip roof venting---you can use the vent you have & maybe incorporate into one of the systems below.

Also Google "hip vent installation instructions", "hip roof ridge vents", "hip roof venting dilemna", "mid america components"

http://www.trimline-products.com/diversiplast/TrimProd.nsf/0/F174DA7427140877862571020080C2D6?Open&Pro
http://en.allexperts.com/q/Roofing-1598/index_all.htm
http://www.miltyr.se/roofing_ridge_master.html
http://www.tapcoeurope.com/ridgevents.htm
http://en.allexperts.com/q/Roofing-1598/Hip-Roof-Ridge-Vents-1.htm
http://en.allexperts.com/q/Roofing-1598/Hip-Roof-Ridge-Vents.htm

Rich73Kelly
Re: Installing roof vent

jts, I didn't plan on the expense and time to install ridge vents. Altho, it might be an option. this is simply a galvanized square dome, or hood, with a 10" pipe rivited to the inside of it. Then there is a flat plate on the bottom to nail it down under the shingles.

Rich Kelly

JacktheShack
Re: Installing roof vent

These vents are known as roof cans and are recommended for hip roofs---they are installed on any one of the sides near the middle top of the roof, 2 to 3' down from the ridge, but preferably the side with the prevailing winds---usually north---some venting at the lower side of the roof is needed to create an air flow for these vents to be effective.

On the inside of the garage, drill a small hole between the exact center of two center rafters about 2' down from the ridge, & stick a nail thru so you can locate the hole on the exterior side.

Check the condition of the shingles before you go on the roof, wear gym shoes---if the shingles are old & brittle walk very carefully---if the shingles are cupped & will break if you walk on them, use a ladder with attached 2 X 3's on the bottom that will rest between the cupped tabs---it is very difficult to get a color match between old & new shingles if the ones on there now are damaged.

Leave the ridge shingles & top layer of shingles in place & remove a few shingles immediately around the nail hole---use a wide putty knife to loosen the sealed-down shingle flap/tabs & a small crow bar to creep under the shingles & loosen the roofing nails so you can remove the shingles without tearing or damage---if the shingles can be bent up without breaking, this job is a lot easier, both for removing the nails, & replacing them---discard the tar paper/building paper under the shingles.

Cut a hole in the plywood/wood sheathing using the previously drilled hole as the center point to match the size of the new vent's hole---smear the bottom of the metal flange that will face the top of the roof with roofing cement & slip this flange of the vent under the upper layer of shingles & push it upwards--- hammer a few nails only in the top and side metal flange---do not put any nails in the bottom flange, which is to remain exposed over its bottom row of shingles---use wide head galvanized roofing nails.

Not sure which way the open side of the vent should face---usually down, there is usually an arrow that indicates proper direction---there are often internal baffles that prevent snow from blowing in.

It can be checked out if you can post the mfgr's name & model #.

Cut & replace the removed shingles around the sides,top & bottom of the vent flanges as needed to neatly match the shingle rows & cover the vent flange, except on the bottom, carefully bending the upper row to slip the shingles underneath--sometimes a few inches has to be cut off the top of the shingle you are trying to slip under so it will go in & neatly match the row---if you can get some nails into the shingles without damaging them, do so.

Use black roofing cement to seal the shingles & any exposed nail heads & nail holes to prevent leaks.

goldhiller
Re: Installing roof vent

Scanned the thread and didn't see this mentioned -

You'll also need intake/soffit vents.

Rich73Kelly
Re: Installing roof vent

JtS, thanks for the detailed explaination. Will make it easier going in. Good thing I asked, I never considered using roofing cement. Thought the shingles would suffice.:o
Goldhiller, the soffits are all vented. I also have a window going out to an enclosed screened patio that stays open through the summer.

goldhiller
Re: Installing roof vent

[QUOTE=Rich73Kelly;32702 Goldhiller, the soffits are all vented. I also have a window going out to an enclosed screened patio that stays open through the summer.[/QUOTE]

Good deal. Then you're set for intake. Thumbs up. :)

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.