Fixing a hot attic

[Leo]

Thanks! I was looking at styles like these. Would they just replace the vent on the rear of my roof? Any harm in doing one of each over those vents?

This is what I have currently on the back of the roof (just a stock pic I found online).

View attachment 280274

I have only installed turbine ventilators on a roof before the shingles. Maybe someone else has more experience with a retrofit situation.

Just like my electric vent fan, I put hinged plywood covers to block the hole under them to hold the heat in during the winter.

 

[Jaybird1980]

I bought a new to me home last year and the attic is very hot, so much so that it's causing the upstairs to be much warmer than the downstairs (even moreso than our last house, which had a lot more sun exposure).

The roof is new and I've adjusted the HVAC vents and have the thermostat using an upstairs sensor, so it's not too bad, but damn. Go into the room with the attic access and it's hot!

I did a quick search online and it appears that the most common resolutions are:

- sealing the attic
- adding insulation
- adding ventilation (powered attic fan)

I think I'm good on the first two, no other room is really warm.

Has anyone added an attic fan? What were your results-oriented? Is this something a roofer would install? If not, then who?

I installed a powered attic fan in the last house, worked great.

I don't have a good way to get electric up into the attic of the new house or I would have already installed one. We have the same issue as you. I have been looking at the solar powered ones, but don't know anyone that has one. I would like to hear from someone that has one and can speak on its durability. The powered one I put in the other house is still going after 20 years.

 

[firecadet613]

I installed a powered attic fan in the last house, worked great.

I don't have a good way to get electric up into the attic of the new house or I would have already installed one. We have the same issue as you. I have been looking at the solar powered ones, but don't know anyone that has one. I would like to hear from someone that has one and can speak on its durability. The powered one I put in the other house is still going after 20 years.

Where did you install it, in a gable vent?

 

[Jaybird1980]

Where did you install it, in a gable vent?

No it was roof mounted and I installed gable vents on each end. The house had soffit vents, but the insulation wasn't done correctly and there weren't baffles installed. So half of the spaces were plugged with insulation.

My buddy had a gable mounted one on his garage and it always seemed to transfer a lot of noise down the wall, so I'm kind of leery of that style.

I had this style.

https://www.menards.com/main/building-materials/roofing/roof-ventilation/air-vent-1320-cfm-roof-mount-power-attic-vent/rv28ml/p-1444423375854-c-13258.htm

 

[firecadet613]

No it was roof mounted and I installed gable vents on each end. The house had soffit vents, but the insulation wasn't done correctly and there weren't baffles installed. So half of the spaces were plugged with insulation.

My buddy had a gable mounted one on his garage and it always seemed to transfer a lot of noise down the wall, so I'm kind of leery of that style.

I had this style.

https://www.menards.com/main/building-materials/roofing/roof-ventilation/air-vent-1320-cfm-roof-mount-power-attic-vent/rv28ml/p-1444423375854-c-13258.htm

Great feedback, thanks! Just one did the trick?

This seems like the ticket. Did you install the gable vents yourself?

 

[Creedmoor]

Good question! I will have to check it out. I would hope not, but can't hurt to check.

Maybe a smoke bomb would tell you.

 

[Jaybird1980]

Great feedback, thanks! Just one did the trick?

This seems like the ticket. Did you install the gable vents yourself?

I used one but it was only a 900sq ft ranch. I did install the gable vents myself. I had aluminum siding so the gable vents were a little bit of work.

How big is your attic space and what kind of siding, and do you have the ability to get electric to it?

 

[Ark]

Heres a question, my brothers home had the same. full soffit vents and ridge venting.
but zero air was flowing through the attic space.
What we found, was underneath the vented soffit was unvented plywood.
We pulled the vinyl and hole-sawed 4" holes and popped in theses screens the local roofing store had and then reinstalled the vented soffit.

On our house we had some kind of plastic or metal flashing on the underside of the roof plywood, way down near the soffits, which kept a couple inches of airspace open. Otherwise the blown insulation would just wind up on top of the soffit vents.

That is hilarious though. Somebody just screwed vents over the solid soffit plywood and was like "there I vented it"?

 

[Ingomike]

That is hilarious though. Somebody just screwed vents over the solid soffit plywood and was like "there I vented it"?

A quite common occurrence….

 

[firecadet613]

I used one but it was only a 900sq ft ranch. I did install the gable vents myself. I had aluminum siding so the gable vents were a little bit of work.

How big is your attic space and what kind of siding, and do you have the ability to get electric to it?

Our house is 2,000sq ft, but I have a completely separate attic over the garage.

Vinyl siding, and I have electric up there (a light in each attic I can steal power from.

In the first picture, you can see the garage attic (left side) and the main attic on the right.

Would the gable vents need to be installed down low or up high in the attic?

 

[firecadet613]

On our house we had some kind of plastic or metal flashing on the underside of the roof plywood, way down near the soffits, which kept a couple inches of airspace open. Otherwise the blown insulation would just wind up on top of the soffit vents.

Now that you mention it, I recall seeing those up there. I'll poke around up there after dinner to confirm.... my brain has been mush with so much going on the past few weeks.

 

[dudley0]

If you have cellulose insulation in the attic look for dusty or light brown spots by the soffit vents. That will help guide you if they are completely covered or not. The air can be blown back and bring some insulation with it.

I put soffit vents in a few of my places after the fact. It is a pain but worth it to make the shingles last longer as well as reduce heat transfer down to the living space. Make sure if you have ridge vents that they cut the roof sheeting away. I have seen that as well. Easier fix but a pain when you paid someone to do it and they didn't.

If you have good circulation you shouldn't need a powered vent in my opinion, especially in Indiana.

EDIT: Just saw your pics.

Personally I would not add gable vents. They will compete with the other vents and not move as much air as you want. Choose one or the other. I have seen gables and ridges used on the same house and that was worthless.

Check your soffit, go from there.

 

[Old Dog]

Your mold situation is probably due to poor air movement in the attic, rather than a shaded roof.
Get that air flowing, to exhaust the moisture and keep the decking as cool as possible.

Be sure that bathroom vents, stove hood, and dryer vents actually vent to outside. I had a house where all of them were vented into the attic, this causes excess moisture to get trapped in the attic.

 

[Jaybird1980]

Our house is 2,000sq ft, but I have a completely separate attic over the garage.

Vinyl siding, and I have electric up there (a light in each attic I can steal power from.

In the first picture, you can see the garage attic (left side) and the main attic on the right.

Would the gable vents need to be installed down low or up high in the attic?

It looks like you have a good amount of ventilation if you also have clear soffits. I would check how much insulation you have.

If your soffit vents are open and the spaces are not plugged with insulation then they will work better with a power vent than the gable vents will. They allow air to be drawn from bottom to top and take out more heat and moisture that way. If you do go with a power vent you can replace one of the centrally located roof vents that are there. The power vent will act like a regular roof vent when not in operation.

If your soffit vents are plugged with insulation then the gable vents go higher in the wall space

Like this. They make 2 piece gable vents that work good with vinyl.

https://www.menards.com/main/building-materials/siding/vinyl-siding-vents/novik-reg-18-x-24-rectangular-gable-vent/24035001/p-1444449743156-c-12404.htm?tid=87f42fbf-a7f4-4933-bc7a-dbe169d4a106&ipos=2&exp=false

 

[BigRed]

I also like a Thermostatic attic fan. Mine vents just the attic.

I have also had one that pushes house air into the attic, from the hallway. The idea is that it pulls air into the house through open windows. That is nice a few times a year, but most of a hot, humid summer you cannot use it.

That actually works very well if you can leave your house open all the time.

 

[Cameramonkey]

Reflective film is helpful. As well as the vents that staple to the rafters to direct the heat along the roof deck directly to the ridge vent (if you have them)

I havent done a full attic of reflective film, but I did have some "fancy" "wedding cake" recessed light fixtures that the IR probe showed was ridiculously hot because they were not well insulated because they got so close to the roof deck. I added some blown insulation and that helped a little, but not by much. So I spread some survival blankets over them and wowsas. Made a HUGE difference. More than the insulation.

So if you can reflect that energy back to the deck, it will help.

 

[firecadet613]

If you have cellulose insulation in the attic look for dusty or light brown spots by the soffit vents. That will help guide you if they are completely covered or not. The air can be blown back and bring some insulation with it.

I put soffit vents in a few of my places after the fact. It is a pain but worth it to make the shingles last longer as well as reduce heat transfer down to the living space. Make sure if you have ridge vents that they cut the roof sheeting away. I have seen that as well. Easier fix but a pain when you paid someone to do it and they didn't.

If you have good circulation you shouldn't need a powered vent in my opinion, especially in Indiana.

EDIT: Just saw your pics.

Personally I would not add gable vents. They will compete with the other vents and not move as much air as you want. Choose one or the other. I have seen gables and ridges used on the same house and that was worthless.

Check your soffit, go from there.

It looks like you have a good amount of ventilation if you also have clear soffits. I would check how much insulation you have.

If your soffit vents are open and the spaces are not plugged with insulation then they will work better with a power vent than the gable vents will. They allow air to be drawn from bottom to top and take out more heat and moisture that way. If you do go with a power vent you can replace one of the centrally located roof vents that are there. The power vent will act like a regular roof vent when not in operation.

If your soffit vents are plugged with insulation then the gable vents go higher in the wall space

Like this. They make 2 piece gable vents that work good with vinyl.
View attachment 280357

https://www.menards.com/main/building-materials/siding/vinyl-siding-vents/novik-reg-18-x-24-rectangular-gable-vent/24035001/p-1444449743156-c-12404.htm?tid=87f42fbf-a7f4-4933-bc7a-dbe169d4a106&ipos=2&exp=false

Thanks! I jumped up in the attic and the soffits do appear to be blocked a bit (maybe/maybe not - you decide). Good to hear I won't need to install gable vents (although I did pick up a few for my barn - look for a thread on where to place them soon).

Plenty of insulation though and a junction box is already there I can tap into.

@Jaybird1980 funny, the fan you linked to is one I found earlier today. They also have a high efficiency one for double the price.

Let me know your thoughts on these pics...

 

[blain]

Those air baffles look fairly narrow. Your truss spacing is 24", correct?

Is the underside of your decking shaggy and de-laminating or is that an optical illusion of the picture?

 

[firecadet613]

Those air baffles look fairly narrow. Your truss spacing is 24", correct?

Is the underside of your decking shaggy and de-laminating or is that an optical illusion of the picture?

I didn't measure, but that sounds about right.

 

[Cameramonkey]

Thanks! I jumped up in the attic and the soffits do appear to be blocked a bit (maybe/maybe not - you decide). Good to hear I won't need to install gable vents (although I did pick up a few for my barn - look for a thread on where to place them soon).

Plenty of insulation though and a junction box is already there I can tap into.

@Jaybird1980 funny, the fan you linked to is one I found earlier today. They also have a high efficiency one for double the price.

Let me know your thoughts on these pics...





View attachment 280387

Wow. Talk about half a**ed. Am I seeing 16" soffit vents on a 24" rafters?
Those are the things I was talking about. They are supposed to staple to the rafters and direct the heat directly to a ridge vent.

If that doesnt work for whatever reason, using reflective film to keep it away from the rest of the attic should help.