Ridge Vent?

Scorask · 09-02-2008, 10:11 AM

Hi all, I will be removing my chimney in a few weeks, thanks to a new direct vent boiler I no longer need it. Also it sits right in the middle of a room I am finishing off in my basement. Anyways, I figured while I was up there patching the hole where the chimney is I wanted to know how easy it would be to install a ridge vent? I am holding off doing the roof for now because we will eventually start finishing off the attic and we aren't sure wether we will be putting in dormers or not, but it would be nice to go into the attic without it feeling like a sauna. Any suggestions?

kok328 · 09-02-2008, 05:12 PM

A ridge vent won't make the attic any more comfortable to a human but, should make for a cooler attic in general.
A ridge vent is very easy to install (in my opinion).
Strip off the shingles covering the ridge, take a circular saw (set to sheathing depth) and cut about 1/2-3/4" from each side of the peak. Cover that opening w/the ridge vent and shingle over the vent (depending on the type/style you use). Be careful though, you don't want more sq. in. of ventiation at the peak than you have a the soffits or you will create a downdraft instead of an updraft. There are formulas and calculation to prevent this but, I'm drawing a blank on the rules of thumb. Perhaps a roofer would be able to lend some advice in this regards.

glennjanie · 09-02-2008, 11:08 PM

Welcome Scorask:
The general rule of thumb is 1 square inch of ventilation for each square foot of attic floor space. The ridge vent is continous and so should the soffit vents (be continous). If you get extra soffit ventilation it will serve to cross ventilate from one side of the house to the other. However, the greatest majority of the air will travel to the ridge vent to exit. Its similar to 'ice house' ventilation; the air travels up the underside of the deck to the ridge, which makes it a lot cooler for the shingles.
Take some temperature measurements before and after you install the new vent system. I assure you, the difference on similar days will be significant (like 30* or more).
Glenn

Scorask · 09-03-2008, 12:26 PM

Quote:

Originally Posted by kok328

A ridge vent won't make the attic any more comfortable to a human but, should make for a cooler attic in general.
A ridge vent is very easy to install (in my opinion).
Strip off the shingles covering the ridge, take a circular saw (set to sheathing depth) and cut about 1/2-3/4" from each side of the peak. Cover that opening w/the ridge vent and shingle over the vent (depending on the type/style you use). Be careful though, you don't want more sq. in. of ventiation at the peak than you have a the soffits or you will create a downdraft instead of an updraft. There are formulas and calculation to prevent this but, I'm drawing a blank on the rules of thumb. Perhaps a roofer would be able to lend some advice in this regards.

Quote:

Originally Posted by glennjanie

Welcome Scorask:
The general rule of thumb is 1 square inch of ventilation for each square foot of attic floor space. The ridge vent is continous and so should the soffit vents (be continous). If you get extra soffit ventilation it will serve to cross ventilate from one side of the house to the other. However, the greatest majority of the air will travel to the ridge vent to exit. Its similar to 'ice house' ventilation; the air travels up the underside of the deck to the ridge, which makes it a lot cooler for the shingles.
Take some temperature measurements before and after you install the new vent system. I assure you, the difference on similar days will be significant (like 30* or more).
Glenn

Thanks to both of you for the quick responses and good advice. Like I said it will only be temporary, 2-3 years. Any advice on how long it should be? Meaning should I start it 5' or 10' from the peak? Or should I run it the entire length? Thanks again.

glennjanie · 09-03-2008, 01:32 PM

Mine is the entire length.
Glenn

kornkob · 09-04-2008, 09:50 PM

Mine starts even with the walls of the house and was installed by the roofing company, for what that's worth.