[mrwilliams2]

I recently had some storm damage to my roof and will be having the shingles replaced in the next couple of weeks. My house is a early 90's construction and has gable vents and what appears to be soffit vents in the overhangs (vinyl siding with holes punched).

My question is should I have a ridge vent added or leave it as is? The estimate didn't include it I assume because I have an existing ventilation system (soffits and gables). I asked the contractor about it and he said it couldn't hurt, but he wasn't sure if it would help...

Any suggestions?

 

[sixeightten]

In the last few years I have heard many people say that in you have the ridge vents, then you should cover up the gable vents. If not, it can disrupt the whole flow of air in the attic. The ridge vent works much better than the gable vents. Since you are having the roof done anyways, it is not an expensive addition. I would go into the attic afterwards and close up the gable vents with plywood. Doesn't have to be 100% sealed, just enough to stop large air movement.

 

[seeyou]

In the last few years I have heard many people say that in you have the ridge vents, then you should cover up the gable vents. If not, it can disrupt the whole flow of air in the attic. The ridge vent works much better than the gable vents. Since you are having the roof done anyways, it is not an expensive addition. I would go into the attic afterwards and close up the gable vents with plywood. Doesn't have to be 100% sealed, just enough to stop large air movement.

That's pretty much an old wife's tale. If you have a ventilated roof system, you'd have a hard time installing too much venting.

With ridge vent AND gable vent, the worst case scenario is that air enters the gable vent and exits the ridge vent reducing the pull from the soffit vents. But you'd still be getting air movement which should remove the moisture. If you're relying on attic venting to keep the inside of the house cool, then you don't have enough insulation.

 

[mrwilliams2]

As far as I know, I haven't had any trouble whatsoever with the system that is in place currently. I don't have a problem with moisture buildup, but it gets sweltering hot in the attic during the summer months. The attic is used for storage only. The roofer said that he could install a ridge vent for around $300 bucks while the shingles were being replaced. I figured that would be a pretty cheap addition. If it will be beneficial, I'll do it. If it won't be helpful, I'll hang onto my $300.

 

[seeyou]

If you have no moisture problems, spend that $300 on insulation. I've seen very few buildings (including my own) in my 30+ year career that couldn't benefit from some more insulation.

 

[Gary in WA]

More ventilation in the attic will reduce the cooling load. Personally, I would add the ridge vent (baffled) and leave the gable vents alone if they are 3' or more above the soffit vents. Depends on the wind direction for so-called "short-circuiting". I would open up the soffit vents more as the perf's are minimal; http://files.buildsite.com/dbderived-f/owenscorning/derived_files/derived92755.pdf You want 9 NFVA per foot of soffit (per side) to match the 18 NFVA of exhaust; http://www.airvent.com/homeowner/products/intakeSoffit-specs.shtml

http://files.buildsite.com/dbderived-f/airvent/derived_files/derived20936.pdf

Gary