[patoline]

Greetings.


I have a sawtooth roof and need to improve attic ventilation but can't find any info on the best way to accomplish this. I'm thinking maybe a ridge vent on top and possibly soffit or louvered vents for intake on the vertical wall but not sure if that will work. Can't have the the intake vents too low due to valleys\rainfall. I live in San Francisco Bay Area so no snow, freezing temps uncommon but can be very hot in summer.

I'll attach a pic of what I'm thinking. Any advice appreciated.


Thx in Advance!

 

[Nealtw]

So, where is the ceiling in all this?

 

[patoline]

The majority of the ceiling is horizonal, I have one vaulted ceiling and some light wells, so there are full attic spaces where I need to improve the ventilation. No idea why the house was built this way.


thx

 

[Nealtw]

The majority of the ceiling is horizonal, I have one vaulted ceiling and some light wells, so there are full attic spaces where I need to improve the ventilation. No idea why the house was built this way.


thx

Maybe a vent at the bottom corner at each end and maybe a box vent in the middle a distance from the bottom . Either of what you have for the high side. Ridge would likely be best.You want more intake than exhaust.

 

[Bud9051]

To encourage natural air flow you want as much elevation difference as possible between high and low vents. The wind will also help, but already built so not much you can do to increase that.

Ventilation is often expected to cool an attic, but the real protection from that heat is great insulation along with air sealing between house and attic. Attics will always get hot.

The other option is an exhaust fan.

Bud

 

[patoline]

Thank you both, much appreciated. Any ridge vent suggestions for this type of application? Most of the ones I see online are for traditional roofs.



Thanks again!

 

[Bud9051]

We should have more details on how you are building this, such as how the fascia and soffit are going together. Where you show "intake/soffit louvered vents is a high position and would probably act as an exhaust vent.

Will there be any overhang of the roof at the peak?
Are the sides exposed to allow a vent as neal indicated?
Aer there any other attic areas connected to this?
Is this all on paper at this point or has construction started?

Bud

 

[patoline]

This is existing construction. No overhangs or soffits or fascia (along the roof ridge); just siding on the vertical side and metal flashing/roof cap at ridge. Very much like a shed.


Sides are exposed but the one "tooth" I'm concerned about has a light well leaving me with two attic spaces with only one side each to install the side vents.


Thanks again, appreciate the help.

 

[Nealtw]

This is existing construction. No overhangs or soffits or fascia (along the roof ridge); just siding on the vertical side and metal flashing/roof cap at ridge. Very much like a shed.


Sides are exposed but the one "tooth" I'm concerned about has a light well leaving me with two attic spaces with only one side each to install the side vents.


Thanks again, appreciate the help.

are those upper walls built around steel or wood girders or are the on a beam or is there a wall below them?
What is the roof material now?
Is it new roof time or not?

 

[Nealtw]

I think a high vent on the upper wall and the low vent on the front and back will work.
Hot or warmer air will always rise if it has a place to go. It will always be replaced by cooler air. So the high vent on each side of the window gives it a place o go and the low vents gives it cooler air to replace it.

We always talk about vent sizes but what is true is there is also speed involved.
If you have ever cut into a hot roof in the summer to install box vents. The first one you open will have a wind of warm air coming out because the heat as created pressure. When you cut the second one there is warm air but the pressure is gone.

I some areas we build houses 8 feet apart, We sheet the soffets, no venting allowed, so we build a skirt roof on the front and back where there can be venting and the air from there feeds the closed soffet with air for the low venting.

 

[patoline]

Wooden framing, ceiling joists, walls, and beams below. Attic is rafters and vertical studs, no trusses. Asphalt shingles over plywood sheathing. Not new roof time yet.


thx!

 

[patoline]

Neal and Bud, thank you very much for your replies and expert advice, very much appreciated.

 

[Nealtw]

Neal and Bud, thank you very much for your replies and expert advice, very much appreciated.

Sealing the ceiling from the attic side is also a good idea.

 

[carpdad]

Passive venting, nealtw image, may not do much, if attic heat is high enough to be felt below through whatever insulation you have and the drywall. More venting with fairly large louver vents, front and back, would exchange more air and look better. Louver vents must be built according to your area (how strong winds) and include sill pans that slope out.