# Enclosed Porch: Insulation between rafters?



## Bud9051 (Nov 11, 2015)

Tough project. Insulation suggests people and their activities and the moisture they bring along. Add any conditioning and the air inside can hold even more moisture. When that moist air leaks into the ceiling and finds a cold surface it will deposit that moisture, thus the needed ventilation to remove that humid air before condensation occurs.

Pictures would help but a note, there are usually building codes in place that will override your plans and our suggestions. In fact a porch like that may not have been an approved addition in the first place. In any case it is always good to check to be sure your plans meet local requirements.

Bud


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## joecaption (Nov 30, 2011)

Got a picture so we can see what your seeing and a location?
The best way would be to build a flat ceiling and insulate that instead of the roof.
Soffit vents with no roof or sidewall vents are useless.
There should have been a vent like this if your not going to build a ceiling.
https://dciproducts.com/shed-roof-roof-to-wall/


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## TimRemo (Aug 13, 2017)

@joecaption Here are some pictures. Originally, there was a porch (or 3 seasons room) roof that was added onto the roof of that 1st floor bump out. It’s pitch created a low ceiling on the porch. We build a shed roof on top so that we could vault the ceiling and make that room seem a little bigger. Plus, it straighted out the roof line too. The old ceiling joists are now useless and will be removed.


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## TimRemo (Aug 13, 2017)

Bud9051 said:


> Tough project. Insulation suggests people and their activities and the moisture they bring along. Add any conditioning and the air inside can hold even more moisture. When that moist air leaks into the ceiling and finds a cold surface it will deposit that moisture, thus the needed ventilation to remove that humid air before condensation occurs.
> 
> Pictures would help but a note, there are usually building codes in place that will override your plans and our suggestions. In fact a porch like that may not have been an approved addition in the first place. In any case it is always good to check to be sure your plans meet local requirements.
> 
> Bud


There won’t be any conditioning to this room. It’s really just an enclosed porch with a door and several windows that I keep open when it’s warm outside. 

As far as codes go, I’m not really sure what rules this room is or isn’t breaking. All I really want to do is just attach some paneling or boards onto the rafters to create a finished slanted ceiling. I don’t know if I should add in insulation first or not. I added some pictures. Maybe that’d help clear some things up? Thanks for the input.


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## TimRemo (Aug 13, 2017)

joecaption said:


> Got a picture so we can see what your seeing and a location?
> The best way would be to build a flat ceiling and insulate that instead of the roof.
> Soffit vents with no roof or sidewall vents are useless.
> There should have been a vent like this if your not going to build a ceiling.
> https://dciproducts.com/shed-roof-roof-to-wall/


I added some pictures for you that may help.

This room actually had a flat ceiling that we removed. It created a 7ft high ceiling and made the room feel tight. I just have to get rid of the old ceiling joists and some old eaves that overhang into that room. 

I know the soffits are useless if we don’t a have vent at the top. We kept those because they were doing no harm. 

I guess I have two options/questions:

1) Do you think even adding R19 fiberglass insulation between the rafters add any benefit for keeping this room from baking in the summer months? I’ve only insulated conditioned spaces...never something like this.

2) If I did add the R19 batts, what would be the side effect of NOT venting at the top? Remember, not a conditioned space, but it is enclosed.

Thanks for the feedback.


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## Nealtw (Jun 22, 2017)

I would remove the ceiling and that portion of skirt roof but I would go up higher and put a small level ceiling so you have a common air space so 2 box vents would work.
I would also add to the depth of the rafters so you have close to 10 inches. so you have room for air chutes from the soffit to the common space at the top. And sealing between living space and insulation is really important.


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## Nealtw (Jun 22, 2017)

Like this


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## TimRemo (Aug 13, 2017)

Nealtw said:


> I would remove the ceiling and that portion of skirt roof but I would go up higher and put a small level ceiling so you have a common air space so 2 box vents would work.
> I would also add to the depth of the rafters so you have close to 10 inches. so you have room for air chutes from the soffit to the common space at the top. And sealing between living space and insulation is really important.


Those old ceiling joists and skirts will definitely be removed. I understand your suggestion for adding a new level ceiling a higher...maybe about 9ft. The bottom of the rafter go as high as 11’. We’d lose a bit of that vault feel and still have to add those box vents. I’m trying to avoid cutting into the roof because I have no experience with that. 

I came across a project here which was similar to mine but his porch is open: https://www.younghouselove.com/well-take-one-beadboard-ceiling-please/

Towards the bottom of the article, he explains how he put a long vent which seems to run parallel with and right underneath his ledger board, but it vents downwards into the room. It seems backwards to me, but I’m no expert. Could this have any benefit? 

I’m tempted to just leave it all exposed, install a pendant style lantern light, and call it a day. Haha.


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## TimRemo (Aug 13, 2017)

Nealtw said:


> Like this


Yes I believe this is the best route. I was reponding to your other post and didn’t see the image, but your explanation made perfect sense. I just want to keep the project simple. Throw some bead board up there, or other paneling, with some simple trim and be done. Adding more to the to-do list (although a better idea) doesn’t come as easy/quick to me. The previous set up had no insulation or roof vents and really caused no issues (that I know of at least).


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## Nealtw (Jun 22, 2017)

TimRemo said:


> Those old ceiling joists and skirts will definitely be removed. I understand your suggestion for adding a new level ceiling a higher...maybe about 9ft. The bottom of the rafter go as high as 11’. We’d lose a bit of that vault feel and still have to add those box vents. I’m trying to avoid cutting into the roof because I have no experience with that.
> 
> I came across a project here which was similar to mine but his porch is open: https://www.younghouselove.com/well-take-one-beadboard-ceiling-please/
> 
> ...


 It always amazes me how people who know nothing proudly post there work on the net. Don't look at that article any more, there is nothing there there you need. 



So you would be happy but for the box vents, watch some videos for that, it not all that scary . Besides that then from that attic space you could cut a vent in the side wall and into the other roof where you do have a box vent.


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## Nealtw (Jun 22, 2017)

TimRemo said:


> Yes I believe this is the best route. I was reponding to your other post and didn’t see the image, but your explanation made perfect sense. I just want to keep the project simple. Throw some bead board up there, or other paneling, with some simple trim and be done. Adding more to the to-do list (although a better idea) doesn’t come as easy/quick to me. The previous set up had no insulation or roof vents and really caused no issues (that I know of at least).



You are changing everything from an unheated box with an attic where the attic gets to disperse heat or cold to a closed tight space with insulation, you can not compare one to the other. We can likely find others with problems caused by taking short cuts.


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## TimRemo (Aug 13, 2017)

Nealtw said:


> You are changing everything from an unheated box with an attic where the attic gets to disperse heat or cold to a closed tight space with insulation, you can not compare one to the other. We can likely find others with problems caused by taking short cuts.


It's actually a pretty similar set up. I have the benefit of seeing everything in person. I'm sure some info is lost over the internet.

The original setup with the short 7' ceiling didn't really have an attic space. The largest gap between the bottom of the rafters and ceiling joist had to be a matter of inches, just barely enough for a pitch. It had little to no insulation and no venting. I'll attach 2 pictures so you get an idea. There were no issues. The new set up would be similar, just with or without insulation. Actually, the 2nd story addition provides a lot of coverage from the sun, so the roof is exposed to the sun for much less time. It's probably be slightly better.

I know you disagreed with that article. I questioned the venting method too, but maybe it works for their situation. There's a lot to factor into every job. If I left my setup as is, there's not much of a downside.


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## Nealtw (Jun 22, 2017)

@ TimRemo


Yes I understand but in this wall you can put a vent in the wall just below the rafter 













In this picture we can see a box fent for the other roof








In this picture we can see the two roofs are common and a hole could be cut there to allow venting 









Continued.


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## Nealtw (Jun 22, 2017)

@ TimRemo


If you remove the ceiling some of the roof sheeting should be removes so the wall can be continued up the roof, unless that is done already. 











Building a ceiling is placing a 2x8 directly below the ledger that is holding the rafters
Add short 2x4 level with the bottom of that 2x8 out level and nailed to the rafters.
Then add blocks between the 2x4 at the 2x8. 

The ceiling would be an hour or two.


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## Nealtw (Jun 22, 2017)

They built this wall an top of the ceiling so that wall will have to be reconstructed or something. Maybe just cut the joists and put another plate on top of the joists and build an inner wall.


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## TimRemo (Aug 13, 2017)

Nealtw said:


> They built this wall an top of the ceiling so that wall will have to be reconstructed or something. Maybe just cut the joists and put another plate on top of the joists and build an inner wall.


Ok ok ok maybe you convinced me to do it this way. :smile: Let me run it all past you. So, you are thinking a side vent, like a small gable type vent on the "triangular wall side." Did you have a style/size in mind? My knowledge is pretty limited for those products. And would this vent be all I need or do I really need to cut into the other roof where the box vent is?

With that said, which vertical 2x4 in my attached picture would you take the level ceiling on to? I numbered them and added a horizontal line just to make sure I understand how you recommend extending out a 2x4 for the ceiling. Keep in mind we'd really like the ceiling as high as possible. 

Lastly, I attached a picture of the current inside where the roofs meet. If I extend that back bedroom wall straight up, it's falls between 2 rafters (marked with red x's). I rough sketched the framing of that wall extension I'd frame out. The blue lines symbolize the rafters of that back bedroom. I'd just cut into those? Like a 16'' by 1 foot hole? The I'd put plywood (or whatever) over that new mini wall extension and put a vent on that too?

Thanks for all your feedback!


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## Nealtw (Jun 22, 2017)

Yes you would cut the old roof sheeting back so the new sx6 studs get nailed to the top plate of the wall below so drywall or what ever is smooth up that wall. 

That dead space will get hot in the summer so I do think you want a hole as high as you can get to the left of the left blue line




















You understand it is a guess from here but you want a space above the insulation so about 2 or 3" below the rafters at the top would give you a very small space but a space. So what ever thickness of insulation and that 3" gap would be the height of the bottom of the 2x4s My guess it would be between your 2 and 3.
So on that wall just measure down 13" from the bottom of the rafters and draw a level line on the side wall and see what you think of that. 

The vent for the side wall I suspect we can find something, the structure for that upper left wall will need to be looked at closely before you can remove the joists. 

Once you have the joists out there will be no reason the old piece of roof that was left can't be removed.


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## TimRemo (Aug 13, 2017)

Nealtw said:


> Yes you would cut the old roof sheeting back so the new sx6 studs get nailed to the top plate of the wall below so drywall or what ever is smooth up that wall.
> 
> That dead space will get hot in the summer so I do think you want a hole as high as you can get to the left of the left blue line
> 
> ...


Alright. The small vent I could find at first glance is 8"x8". Think That'd get the job done? Link below.

The next popular size up looks like 12"x18". This means the mean would be exposed to the tiny attic space I create above the ceiling, but it'd also vent some of the area just below the ceiling too (I think). 18" vertically. This would be fine, right?

By the way, you mentioned 13" inches in your last post. You lost me on that number. Was that your estimate or did you calculate that from somewhere?

https://www.ventmyhouse.com/8-x-8-white-square-vinyl-standard-gable-vent-price-per-piece-item-620808/?_vsrefdom=adwords&gclid=Cj0KCQjw4fHkBRDcARIsACV58_Efs8jGnWaLhLNYx4-Kl8D_9_PvkYuZss3c8L9I1uJPc0C8biYjHKUaAhNYEALw_wcB

https://express.google.com/u/0/product/3340742132044077489_7270701945508076612_1183006?utm_source=google_shopping&utm_medium=tu_prop&utm_content=eid-lsjeuxoeqt&gtim=CJT1wajKyISgPBDigOjf6OGK5fsBGNCM1w0iA1VTRCjwpK_lBTCemkg&utm_campaign=1183006&gclid=Cj0KCQjw4fHkBRDcARIsACV58_Ge5BMzm1v1Ho6Z7TU-JBnju3ULwqPPI4z7y-nyY09cQaRWz6hZSlgaAo3eEALw_wcB


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## Nealtw (Jun 22, 2017)

TimRemo said:


> Alright. The small vent I could find at first glance is 8"x8". Think That'd get the job done? Link below.
> 
> The next popular size up looks like 12"x18". This means the mean would be exposed to the tiny attic space I create above the ceiling, but it'd also vent some of the area just below the ceiling too (I think). 18" vertically. This would be fine, right?
> 
> By the way, you mentioned 13" inches in your last post. You lost me on that number. Was that your estimate or did you calculate that from somewhere?


We are trying to get what ever we can get with the small space under the rafter we are talking about, the vent might be as small as a dryer vent. That's why I think the hole into the other roof will help too.


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