Installing roof venting

[Jim O'Dell]

I need to install some sort of roof venting for the shop. The main and original structrue is a 20X24 building. Sometime afterward, a patio was poured, and then covered, tying onto the existing roof. They did a quick/cheap job in that they didn't remove the roof sheathing where the new roof tied in. What type of venting would be best. Continuous ridge vent, or the old standby turbine? If you like the ridge vent, and I'm leaning this way, how do you tie 2 ridges together? Do you leave a gap and shingle over the gap so it's not noticeable? Is there some sort of pre-fab union that is used? I've looked on a couple do it yourself sites, and manuacture's sites, but don't see this addressed. Thanks! Jim.

[Ken Garlock]

Jim, ridge vent is the way to go, IMO. The ridge vent gets rid of the heat where it wants to collect, at the highest point in/on the roof. Whatever you install, make sure that you have a bunch of soffit vents to supply fresh cooler air. You want to create an upward draft of air.

There are pre-formed strips that nail over the opening in the ridge, and then you shingle over the strips just like the original shingles were before the vent strips. I don't know where you get the strips.


I wouldn't waste my time putting in a turbine vent. But, if in some fit of madness you do decide on the turbines, never cover them up in the winter. An attic needs ventilation the year around.

[Jerry Olexa]

I understand ridge vent (continuous) is best but can't hep u with tie of the roof angles. I think you could just install and end before the roof angles meet.

[Jim O'Dell]

Thanks Ken and Jerry. The only thing in the back of my mind that still wants to think about turbines is that is what's on the house, and would therefore match. But I think I would have less of a possible leak problem with the ridge vents. Lowe's here is supposed to carry one brand, according to the manufacturer's and Lowe's web sites. 2 different models. I think I could stop the short ridge piece about 3 or 4 inches before the edge of the main ridge, then cover the gap with shingle and it wouldn't be visible. Maybe even undercut the guts out and leave the top piece for continuity and something for the shingle to sit on.
Thanks for reinforcing the ridge idea. Oh, and Ken, when I put up the hardiboard siding and painted it, I didn't paint the eaves on purpose knowing whichever type of venting I used I would need vents cut into them.:D Jim.

[Art Mulder]

I wouldn't waste my time putting in a turbine vent. But, if in some fit of madness you do decide on the turbines,....

I believe that the TOS forbids linking to other forums, so I can't put in a link. However, I have read the personal testimony of another fellow named Ken, this one located in Manitoba, as to how useless the turbines are. This was on one of the Canadian WW web forums.

He has a max/min thermometer with a sensor in his attic. He used to have a power vent in the attic, which died. He ran one season without, and then put in the turbine (aka Whirly Bird). The temperatures were no different.

That is, the turbine gave the same venting to the attic as the DEAD power vent gave.

[Peter Mc Mahon]

Hi Jim. I am assuming that you have a gable roof on your shop and the patio roof extends all the way to the ridge of the shop roof? If this is the case then I would not use continuous ridge venting because you will only be getting about 50% of your venting [only half of the vent strip will be venting the untouched side of the roof] I would think that a regular roof vent or turbine would be a better way to go. The building code around here is to vent 1/300 of your insulated ceiling area. If your insulated ceiling area is 300 sq. ft. then you need 1 square foot of ventingl. 50% of this is soffit venting and 50% is ridge [turbine, whatever] venting. Remember that soffit venting is just as important as ridge venting. Peter

[Jim O'Dell]

(snip) If this is the case then I would not use continuous ridge venting because you will only be getting about 50% of your venting [only half of the vent strip will be venting the untouched side of the roof] I would think that a regular roof vent or turbine would be a better way to go. Peter

Peter, the main shop section is a gable roof. The patio section is a hip roof. But I'm either still asleep this morning,:rolleyes: , or otherwise just missing something in the copied part of your post above. What do you mean about only half of the vent strip venting the untouched side of the roof? I plan on the vent strip being installed nomally along both roof sections' ridges. My problem is when installing on the porch side, how to configure where these 2 meet. Does this make sense?? Thanks! Jim

[Cecil Arnold]

Jim, don't know if this helps, but ridge venting is the only way to go. I have a "T" shaped hip roof with three levels of ridge and had vents installed last month. The ridge vents run most of the length of the ridge, but stop about 12-18" from the end of the ridge and any transitions in ridge height. From what you describe, I think you would stop the ridge vent on the porch side before it intersects the other section.

[Jim O'Dell]

Thanks, Cecil. How do the transitions look, if they are stopped that far back? Or is it just the cut hole that is stopped there and the vent cap spans part/all of the transition area? I need to get out and go look at some houses that have it to see how they have been done. Jim.

[Cecil Arnold]

Jim, here's about 3000 words (3 pics) od how mine is done. This is a retrofit, as the builder chose to use a power vent, which IMHO, is a really bad idea in this part of the world.

[Peter Mc Mahon]

Hi Jim. I think that I was just reading the post wrong. I was imagining [from the front] a gable end roof on your shop and a gable roof over the patio tied onto the peak of the shop roof effectively covering half of the shop roof. There is a shop around here that is like that and I guess it was stuck in my head. So I would just use roof vents continuous or otherwise with the correct amount of venting [ask your building dept.] with 50% above and 50% below. Peter

[Jim O'Dell]

Thanks Peter. It was early and I was still pretty foggy. Now I've spent the day out in the shop getting hot, and not sure I'm any better. :rolleyes:

Cecil, I read slow, so pictures are good! :D That helps a bunch!! Thanks for taking the time to take and post the pictures. Jim