# No vents in garage build. Will I experience issues?



## Nealtw (Jun 22, 2017)

You should have soffit and ridge vent don't plan on a floor above, ceiling strong enough to have drywall would be enough work on it's own and you will want insulation too. 


That is a poor picture but a guess would make it 20 feet x 20 feet?


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## mathbishop (Sep 20, 2017)

Nealtw said:


> You should have soffit and ridge vent don't plan on a floor above, ceiling strong enough to have drywall would be enough work on it's own and you will want insulation too.
> 
> 
> That is a poor picture but a guess would make it 20 feet x 20 feet?


here is a larger image. But yea, 20x20. The exposed joist ceiling will mostly be for aesthetics and double as easy storage when its an attic. Ill look for some soffit and ridge vents again...


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## Nealtw (Jun 22, 2017)

Any kind of floor would require at least one engineered beam maybe two, 
Exposed from below would change everything to do with insulating the upper part.
The storage you have up there now is way to much for the structure.


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## mathbishop (Sep 20, 2017)

Nealtw said:


> Any kind of floor would require at least one engineered beam maybe two,
> Exposed from below would change everything to do with insulating the upper part.
> The storage you have up there now is way to much for the structure.


So just had another look, definitely no soffit or ridge vent. The plan is to get 12 22' 2x4's and lay some planks along the top of them for storage/insulation. Would I not just insulate it the same way I would if I were just installing drywall? (laying R38 or something similar over the boards) 

I figured I was over engineering it by not having drywall on the ceiling...


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## Nealtw (Jun 22, 2017)

20 foot 2x10s with floor will sag under it's own weight, been there done that.


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## HenryMac (Sep 12, 2018)

mathbishop said:


> There arent any air vents in the garage and im wondering if I will encounter any problems down the road if I dont put any in. I live in southern ca so its very dry in the summer, it can rain pretty hard this time of year but usually not for prolonged periods of time.


So I'll probably get flamed for saying this..... but don't be so quick to listen to the folks telling you to add vents.

It's all about location.. location.. location.

Every home I've ever owned had a copious amount of vents in them.. except for our current home.

It was built in 1978. I has one small roof vent and no soffit vents. We live in the mountains of Central Colorado.

The attic looks like it was built yesterday.

The kicker... very low humidity (we have cactus growing in our yard) and it doesn't get very hot here (no air conditioning).

Additionally, roof vents can be a big problem in areas prone to forest fires. If there is air flow through the attic, then that same air flow can pull airborne embers up into the attic.

And you can't ask the local building / zoning folks... they will simply quote you chapter and verse from the IBC (International Building Code) That code has the same rules for the hot humid everglades of Florida... as it does for the hot arid desert of Arizona.

Like I said.. folks will disagree with what I have written here. But I've got a 41 year old home, with one vent, and no signs of any issues.

The best indicator of what works well.. is what other older homes have in your area, and what condition their attics are in.


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## Nealtw (Jun 22, 2017)

I guess we should ask location.


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## Bud9051 (Nov 11, 2015)

@*HenryMac* not really a flame, but do you really advise everyone to follow your example which probably represents less than .001% of the population. Anecdotal guidance can be far from the best when those examples only fit rare and specific environments.

Glad your home is doing well but codes and guidance are meant to help a wider population.

Bud


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## HenryMac (Sep 12, 2018)

Nealtw said:


> I guess we should ask location.


.....



mathbishop said:


> I live in southern ca so its very dry in the summer, it can rain pretty hard this time of year but usually not for prolonged periods of time





Bud9051 said:


> @*HenryMac* not really a flame, but do you really advise everyone to follow your example which probably represents less than .001% of the population. Anecdotal guidance can be far from the best when those examples only fit rare and specific environments.
> 
> Glad your home is doing well but codes and guidance are meant to help a wider population.
> 
> Bud


Nope, I don't advise "everybody", what would make you say that? 

The OP in this thread lives in Southern California...


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## Bud9051 (Nov 11, 2015)

If your advice doesn't rhyme with the local codes where the op lives then it is bad advice. Sorry to be a pain, but lacking research beyond a one of a kind example doesn't give that argument much weight. Even when there is evidence pointing one way or another it is the local authority that decides which path to follow. 

Bud


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## Nealtw (Jun 22, 2017)

I can understand the fire hazard and maybe no vents in that really dry area but you must have a good seal between the house and attic. 


The problem here besides the structural issues is that a mini split would not keep up with a full cavity of the garage if he insulates the rafters. So ceiling insulation is called for but that also calls for a sealed ceiling. With out sealing the ceiling the insulation is pointless and if it is installed and allows some air movement then venting becomes even more important.


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## HenryMac (Sep 12, 2018)

Bud9051 said:


> Even when there is evidence pointing one way or another it is the local authority that decides which path to follow.
> 
> Bud


You are absolutely right. 

Logic and proportion have fallen sloppy dead.


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## mathbishop (Sep 20, 2017)

Nealtw said:


> 20 foot 2x10s with floor will sag under it's own weight, been there done that.
> 
> 
> https://www.youtube.com/watch?v=cTW1wsmakA4


I should have mentioned there will also be some vertical 2x4's for support so that the long 2x4's dont sag. Truth be told, this is not going to have an inspection, like most DIY projects. But that doesnt mean it shouldnt be up to safety standards. This is going to be a space for me to work and have clients over, the storage space that would be added by putting planks along the top wouldnt hold much more than what is currently up there. Drywall is the least inspiring material, certainly gets the job done effectively but this needs to be an inviting room that people feel creative in. And in my opinion drywall isnt the answer.


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## Nealtw (Jun 22, 2017)

Understood, I would like to be able to give some ideas that would solve all the problems you could have but I don't think I can.


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## NotYerUncleBob2 (Dec 29, 2017)

Is this an attached or detached garage? If it's detached, you'll have some more options. 
First, I'd recommend ditching the idea of overhead storage. Even though _you_ won't put anything heavy up there, what's to say the next person won't? Or your friend or coworker won't climb up there to get that box in the back? Keep it simple and keep it clean.
Now, let's deal with the subject of venting. Venting is key to allow the underside of the sheathing to dry out when it gets condensation on it. Condensation is very possible even in SoCal just from people in there on a cool morning. If you heat and cool the space, then it's even more likely. The reason there are no vents on the roof right now is because the entire space is open, uninsulated, and not conditioned so it essentially keeps the same humidity and temperature as outside and has ample space to move air and dry.
If you want to condition the space, insulate it, and keep the open rafter look, there is an option. Insulate the top of the roof. You'll need to pull the shingles off then put down a few inches of rigid foam, then plywood/osb, roofing felt, shingles, (and a few more details). Under this method you keep the underside just how it is but still get some R value from the roof and as a bonus you get nice high ceilings. 
The other option is to leave the ceiling uninsulated and just blast that mini split turned up to 11 24/7 and try not to sweat/shiver.


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## mathbishop (Sep 20, 2017)

NotYerUncleBob2 said:


> Is this an attached or detached garage? If it's detached, you'll have some more options.
> First, I'd recommend ditching the idea of overhead storage. Even though _you_ won't put anything heavy up there, what's to say the next person won't? Or your friend or coworker won't climb up there to get that box in the back? Keep it simple and keep it clean.
> Now, let's deal with the subject of venting. Venting is key to allow the underside of the sheathing to dry out when it gets condensation on it. Condensation is very possible even in SoCal just from people in there on a cool morning. If you heat and cool the space, then it's even more likely. The reason there are no vents on the roof right now is because the entire space is open, uninsulated, and not conditioned so it essentially keeps the same humidity and temperature as outside and has ample space to move air and dry.
> If you want to condition the space, insulate it, and keep the open rafter look, there is an option. Insulate the top of the roof. You'll need to pull the shingles off then put down a few inches of rigid foam, then plywood/osb, roofing felt, shingles, (and a few more details). Under this method you keep the underside just how it is but still get some R value from the roof and as a bonus you get nice high ceilings.
> The other option is to leave the ceiling uninsulated and just blast that mini split turned up to 11 24/7 and try not to sweat/shiver.


Appreciate the feedback, thank you! how would I have a safe and sturdy way to get that look in the first reference image? would I need an engineered beam?


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## NotYerUncleBob2 (Dec 29, 2017)

mathbishop said:


> Appreciate the feedback, thank you! how would I have a safe and sturdy way to get that look in the first reference image? would I need an engineered beam?


Paint all the existing rafters white. Done.


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## mathbishop (Sep 20, 2017)

NotYerUncleBob2 said:


> Paint all the existing rafters white. Done.


So your saying I cant drop the ceiling like the one in the picture and insulate it like I would do if it were drywall? Id like to keep it as efficient as I can when trying to cool/heat.


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## Porsche986S (Dec 10, 2017)

My 2 cents: Lose the idea of attic storage for the reasons mentioned by others . Another idea for a finished ceiling is metal roof panels . You can do your 2x idea to run side to side but you will only need them every 4 ' or so . I am quite sure you can find someone locally that sells metal roof/wall panels . Buy 10 ' and 12 ' so you have an overlap at the central seam . Rent a ceiling jack like you would for sheetrock . Screw the panels to the 2x's you installed . When you are done you now have a completed ceiling that doesn't need to have drywall mud , sanded , primed and painted . You then place your ceiling insulation on top of the metal panels . You are basically making a ceiling similar to what is in a pole barn . I just did this in my 26 x 28 man cave . It is not the look that everyone wants but I like it . A little bit industrial looking but reflects light very well . Just another option to consider .


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## Porsche986S (Dec 10, 2017)

Forgot to add I agree with others soffit vents and ridge vent are highly recommended .


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## carpdad (Oct 11, 2010)

https://www.bc.com/content/uploads/2018/09/W-spec-guide-BCI-and-VL.pdf


This should give you some idea. Page 28 for beam specs. Total load with deflection L/240 means a dead load which includes the beam itself, 2x4 joists and 2x4 decking you are planning. This does not include any plan for insulation since if you insulate above the decking you can't put stuff on the insulation. If you want storage then you have to raise the floor which becomes a live load. One way or another, you can't have both unless you are willing or know enough to take that chance. Thing is, people do stuff like this everyday, lot of them just assuming it will work. I can't assume that for you in this case because few examples I've seen were sagging.


This is going to be an office space. Consider using a mid post. Desks can be arranged around it. My garage has one. I wish there wasn't one, but it is not even a minor inconvenience. I would be tempted to support that post with lumber footing above the slab.:smile: I said it, but the risk is all yours. Chances are against you and me. Slab has voids underneath, but your load is light.



If insulating and decking, consider even a thin ply above the decking and air sealing before your insulation. Then use active fan venting the attic. Passive venting will keep the attic hot and you need above min code insulation (r38?) not to feel the heat and keep the ac usage efficient.


After this, you may find that unclebob has given you a simple answer without the least headache.:smile:


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## mathbishop (Sep 20, 2017)

Thank you all for the information! I certainly dont need the storage up the there. There much up there now and chances are I can throw it all out anyway. I just had a talk with my buddy who is the "mastermind" behind the idea and he said he was planning on using some strong ties to mount all the 2x4s. Then tie them to the rafters so they dont sag. We would then lay the planks on those and im thinking probably putting an airtight barrier then insulation. 

This is assuming I get all the proper ventilation sorted out.


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## Bud9051 (Nov 11, 2015)

An air tight barrier would not be possible as you described. Not trying to be a problem maker, but very small leaks can allow a lot of moisture to move from below to attic where it can deposit condensation. 

I'll go away to let you continue.

Bud


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## mathbishop (Sep 20, 2017)

Bud9051 said:


> An air tight barrier would not be possible as you described. Not trying to be a problem maker, but very small leaks can allow a lot of moisture to move from below to attic where it can deposit condensation.
> 
> I'll go away to let you continue.
> 
> Bud


Im in need of advice, so please dont go away, lol. Im getting more confused... If im adding ventilation wouldnt that help with any sort of condensation problem? When I say"air tight", that is an overstatement. I really just mean some sort of membrane so there wouldnt be any weird drafts if there are weak spots after insulating. 

Additionally, lets say I wanted to go the drywall route. How would I proceed? I know sheets of drywall are not light and not considerably strong....


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## Bud9051 (Nov 11, 2015)

It is hard to advise based upon intended use. Once constructed a future home owner might not understand the limits of how it was built or intended to be used. That is where building codes come in to ensure any construction will meet any permitted use within the zone it was constructed. Tax evaluation, banks, insurance companies, and new buyers all rely on all buildings having been constructed to conform to the appropriate building codes when built. It is not your intended use that determines how it should be built but the determination of your local building officials. And those requirements can vary from zero to beyond belief. 

Your starting point should be submitting your plans to your local building department as best you can. If they need more details they will tell you. If they approve of what you draw up, get them to sign it and keep that incase others ask. In our new age of computers storing everything checking for past permits and inspections is being done everywhere. I would not buy a home without verifying all construction was approved and inspected.

Once you have your town's approval then we may be able to advise on how to meet or exceed those requirements.

Bud


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## mathbishop (Sep 20, 2017)

Bud9051 said:


> It is hard to advise based upon intended use. Once constructed a future home owner might not understand the limits of how it was built or intended to be used. That is where building codes come in to ensure any construction will meet any permitted use within the zone it was constructed. Tax evaluation, banks, insurance companies, and new buyers all rely on all buildings having been constructed to conform to the appropriate building codes when built. It is not your intended use that determines how it should be built but the determination of your local building officials. And those requirements can vary from zero to beyond belief.
> 
> Your starting point should be submitting your plans to your local building department as best you can. If they need more details they will tell you. If they approve of what you draw up, get them to sign it and keep that incase others ask. In our new age of computers storing everything checking for past permits and inspections is being done everywhere. I would not buy a home without verifying all construction was approved and inspected.
> 
> ...


Thank you Bud, and I agree 100% with what your saying but this seems counterintuitive to DIYchatroom. Sounds like im better off hiring a contractor to do all this. I would love to learn how to be able to build this to code and strong enough to last for whoever owns after me. But Im still at a loss on where to start with this properly. I understand submitting plans, getting approved and permitted but its obvious I am not up to speed on code standards so its also obvious I wouldnt know where to start in submitting proper plans. I was not planning on getting this permitted or approved by the city as this can be a long drawn out process if im not a contractor and comes with a cost. I was hoping to over engineer this to meet any code requirements and surpass any safety standards on my own (with the help of a buddy in construction). I think at this point ill get some quotes from local contractors and go from there. Again, thank you everyone for the input.


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## Bud9051 (Nov 11, 2015)

You start with a knock on the door to that local building department. Getting off on the right foot can go a long way with local officials. The vast majority I have worked with have been extremely helpful as they deal with people like you all of the time.

You can still DIY and the forum can help.

Bud


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## mathbishop (Sep 20, 2017)

Bud9051 said:


> You start with a knock on the door to that local building department. Getting off on the right foot can go a long way with local officials. The vast majority I have worked with have been extremely helpful as they deal with people like you all of the time.
> 
> You can still DIY and the forum can help.
> 
> Bud


Unfortunately, in Los Angeles county you must submit plans. Just talked to a representative and they dont offer advice. Basically saying plans need to be submitted and approved then construction can begin. 

Back to me thinking I might need to hire someone. Drawing up plans and submitting them is beyond my capabilities and desires.


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## Bud9051 (Nov 11, 2015)

California wants plans if you want to walk down the sidewalk.

Sorry, but far better to learn this now than later when the fines kick in and the project has to be removed, it happens.

Bud


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## Nealtw (Jun 22, 2017)

mathbishop said:


> Unfortunately, in Los Angeles county you must submit plans. Just talked to a representative and they dont offer advice. Basically saying plans need to be submitted and approved then construction can begin.
> 
> Back to me thinking I might need to hire someone. Drawing up plans and submitting them is beyond my capabilities and desires.


 Best plan so far. :wink2:


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## NotYerUncleBob2 (Dec 29, 2017)

mathbishop said:


> Sounds like im better off hiring a contractor to do all this.


Maybe. But we do like to do it ourselves around here and we're happy to offer advice where we can. Not really sure what your skills are at this point, so maybe it will be too much for you to complete properly, or maybe this will be just enough of a challenge to allow you to learn and still wind up with a good result. 


mathbishop said:


> I would love to learn how to be able to build this to code and strong enough to last for whoever owns after me. But Im still at a loss on where to start with this properly.


Start by listing what your goals are. Then look for some inspiration in what you want the style to be. Then come up with a design that you can use to figure out the cost and how to do it right. 


mathbishop said:


> I understand submitting plans, getting approved and permitted but its obvious I am not up to speed on code standards so its also obvious I wouldnt know where to start in submitting proper plans.


Everyone who does it all the time has had to do it the first time once. Check with your building department for what their plan standard is. It might sound intimidating, but it's usually translatable to simple ideas like the drawing should be to scale, show the property, show the existing structure and what the planned renovation is. But...sometimes when you talk to them you'll find out that you don't even need a permit for certain things. In my town, I was able to convert my two car garage to office space with only an electrical permit because I didn't change the structure substantially enough to warrant a permit. If you're not changing the number or placement of windows and doors, and not adding a second floor/storage loft, you might not even need a construction permit as adding drywall and insulation is often allowed without a permit.


mathbishop said:


> I was not planning on getting this permitted or approved by the city as this can be a long drawn out process if im not a contractor and comes with a cost.


Nope. Don't try it. If you need a permit and don't get one, you can get in serious trouble on a couple fronts. First, if the city catches you they will fine you, make you get a permit, and make you undo/redo whatever you've already done. If something happens like someone falls off the storage loft, your insurance might not cover you as it's an illegal construction. When you sell the place, you can have all sorts of problems with an unpermitted renovation.


mathbishop said:


> I was hoping to over engineer this to meet any code requirements and surpass any safety standards on my own (with the help of a buddy in construction).


If you're not getting a permit, how do you know you're "over engineering" it? Nobody builds a deck planning to have it fall down, and yet plenty of them do. Every collapse or failure was thought to be over engineered when built.


mathbishop said:


> I think at this point ill get some quotes from local contractors and go from there. Again, thank you everyone for the input.


That's not the worst idea, but if you want to do it yourself we can still help.


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## NotYerUncleBob2 (Dec 29, 2017)

mathbishop said:


> So your saying I cant drop the ceiling like the one in the picture and insulate it like I would do if it were drywall? Id like to keep it as efficient as I can when trying to cool/heat.


You can, but I was offering another option that keeps the roof insulated without building another ceiling. You just insulate the top of the roof with rigid foam and then roof over that. You don't touch the inside so you can then paint the rafters that you see there right now for the whitewashed rafter look. 


> If you want to condition the space, insulate it, and keep the open rafter look, there is an option. Insulate the top of the roof. You'll need to pull the shingles off then put down a few inches of rigid foam, then plywood/osb, roofing felt, shingles, (and a few more details). Under this method you keep the underside just how it is but still get some R value from the roof and as a bonus you get nice high ceilings.


It might not pencil out for cost since you'll be adding roofing, but if your roof is due to be replaced soon then it's a good option.


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## NotYerUncleBob2 (Dec 29, 2017)

One more thought on this... _IF_ this is a detached garage with gables on both sides, you might be able to get away with a pair of gable wall vents instead of soffit and ridge vents. 
This way you can put up the ceiling you want and insulate it like it's an attic. 
I still wouldn't use it for storage though, unless you run a beam and proper rafters and supports and all that.


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