Moving Insulation...removing and adding


  #1  
Old 01-14-16, 12:05 PM
A
Member
Thread Starter
Join Date: Aug 2010
Location: USA
Posts: 388
Received 2 Upvotes on 2 Posts
Moving Insulation...removing and adding

Pretty simple attic structure. This is second story, the ceiling here is 10' and the roofline is 6'. The roof line has R19 and the ceiling has R11. I want to beef up the ceiling insulation and get it closer to code minimum and I want to do that by removing what they put in the roof rafter and adding it to the ceiling. Is there any harm in this? I believe its pretty much totally useless and as it stands, blocking a bit of air flow. Ive never seen a conventional build put insulation in the roof rafter like this.

https://goo.gl/photos/etxNeLkjvKcfSSTcA
 
  #2  
Old 01-14-16, 12:08 PM
S
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 19,125
Received 1,263 Upvotes on 1,204 Posts
I think your plan is sound - get the insulation out of the rafters and install ventilation there while adding insulation to the floor.
 
  #3  
Old 01-14-16, 12:47 PM
A
Member
Thread Starter
Join Date: Aug 2010
Location: USA
Posts: 388
Received 2 Upvotes on 2 Posts
There IS ventilation...a LOT...there is a large ridge vent. You just cant see it! LOL.

I believe this plan of putting the rafter insulation in the ceiling was discussed before but I want to verify.

There is no chance this insulation in teh roof line is doing anything aside from dampening the noise right? Removing this wont make my attic HOTTER will it?
 
  #4  
Old 01-14-16, 12:50 PM
B
Member
Join Date: Oct 2008
Location: New England
Posts: 9,460
Received 47 Upvotes on 43 Posts
Hi ag,
That's a tough one. The rafter insulation is installed poorly and we don't know if there are air channels between the insulation and the roof deck, plus intake and exhaust. R-19 would fill 2x6 rafters and that insulation is not stapled flush.

But, besides that attic being a mess, you are in a hot climate with ducts up there so can benefit from a well insulated roof and a conditioned attic.

If there are just the ducts we see and no ac unit up there you can proceed as planned, ventilation as ss noted, code level below. In addition to increasing the ceiling insulation, before you bury it, you should air seal everywhere possible. I'm not sure what electrical codes relate to all of those wires being buried, not my field, but should at least be neat.

Bud
 
  #5  
Old 01-14-16, 02:22 PM
A
Member
Thread Starter
Join Date: Aug 2010
Location: USA
Posts: 388
Received 2 Upvotes on 2 Posts
It is installed poorly? Why do you say that? Because they installed so close to the ridge vent? There is a gap between the roof deck and the insulation. Its beween 1 and 3" depending on where you check.

None of my insulation is stapled flush. Its is ALL inset stapled. nothing can be done about that now though. This was done 10 years ago and I wasn't party to that .
 

Last edited by agdodge4x4; 01-14-16 at 02:37 PM.
  #6  
Old 01-14-16, 03:09 PM
B
Member
Join Date: Oct 2008
Location: New England
Posts: 9,460
Received 47 Upvotes on 43 Posts
Not judging you ag, but in my profession we have to classify the installation of insulation and insert stapling produces a very irregular surface both above and below. If we looked at the insulation with an infrared camera you would see varied temperatures indicating varied insulation levels. Where this was done on a vertical wall and covered with drywall you would lose a few notches on your assembly r-value. It is a common method, but not the best for r-value or as a vapor barrier.

I thought you would yell at me for calling your attic a mess .

Bud
 
  #7  
Old 01-15-16, 06:37 AM
A
Member
Thread Starter
Join Date: Aug 2010
Location: USA
Posts: 388
Received 2 Upvotes on 2 Posts
Nah...it IS a mess. Contracting crews did that. And I have had infrared scans done and you are absolutely right. You can see R value differences in some spots on the cathedral ceiling where the inset stapling has created an air gap on the edges and its warmer. Is there anything I can do about that without tearing open the drywall? I havn't addressed it because that part of the ceiling is about 4' long and I suspect its pretty minor by comparison to the lack of insulation in the rest of the ceiling.

Is that a fair statement?

Basically, what I want to know is if removing the insulation from the rafters and putting on the ceiling, thereby increasing the R value of JUST the ceiling, is going to be worth the effort involved. Will I notice any gain or benefit from this little exercise?
 
  #8  
Old 01-15-16, 07:31 AM
P
Member
Join Date: Dec 1999
Location: Cleveland, OH USA
Posts: 608
Received 19 Upvotes on 18 Posts
I am no pro but it sounds like 2 different issues. Adding insulation to the ceiling (floor of the attic) will help prevent heat loss/infiltration with the house below. The ridge vents and whatever vents supply the fresh air to them are basically making the space similar to being outdoors. If you want to condition the entire attic space (as if it were a cathedral ceiling) then insulating rafters is helpful but the ceiling insulation may not be. Otherwise it does not sound like the rafter insulation is accomplishing anything.

- Peter
 
  #9  
Old 01-15-16, 07:58 AM
B
Member
Join Date: Oct 2008
Location: New England
Posts: 9,460
Received 47 Upvotes on 43 Posts
Hi again,
Tough question again. The insulation should not be installed as is in the rafters. Insulating a slope has some definite steps that need to be followed to be certain you don't get in trouble with moisture.
HOWEVER, you are already there and it looks like there has been no problem. I would suggest you peek behind a few of those batts in the rafters and if there is no moisture, no panic.

I suspect that attic is a bit warmer than without the rafter insulation, so removing it will give you a colder attic. Between the attic getting colder and only adding r-19 to the ceiling, you will probably not detect a difference or see much of a difference in your heating bills.

If you seal an air leak around a window you stop a draft and feel a difference. If you double up on the insulation in the ceiling the inside surface will change temperature very little. Your heating costs will drop a tiny bit, but you will not feel the change.

Now, R-11 needs to be improved, baffles need to go in, air sealing needs to be done, and all of this can be done before the rafter insulation gets relocated. Upgrading to a traditional r-40 plus attic, well air sealed, will be an improvement. If you are going to have storage up there, or maintain access, I recommend building a raised walkway.

Have to run, will watch.

Bud

But yes, improvement is definitely possible with the right plan.
 
  #10  
Old 01-15-16, 08:35 AM
A
Member
Thread Starter
Join Date: Aug 2010
Location: USA
Posts: 388
Received 2 Upvotes on 2 Posts
Cool Thanks for the insight and advice!

I have airsealed. But I noticed no difference in that either. How does this sound:

1.) relocate rafter insulation to ceiling now - because its free, will increase the insluation R value in the ceiling and bring it level with the ceiling joists.

2.) Install baffles in every other bay of the roof line in the portion that is 'cathedral' to promote air flow. Rafters are 12" OC so that should be more than enough airflow.

3.) Add R30 insulation to the ceiling since I prepped for that on step 1. This will be laid perpendicular to what is already there.

Do you think this will help with the temperature retention in these rooms?
 
  #11  
Old 01-15-16, 09:18 AM
B
Member
Join Date: Oct 2008
Location: New England
Posts: 9,460
Received 47 Upvotes on 43 Posts
If you are confident your air sealing was good, then adding more to the ceiling is ok.

As for the baffles, the objective of air flow isn't to just move the air from intake to exit, it is to remove moisture and heat from the bottom of all rafter cavities. They recommend every rafter bay. The baffles will also keep the insulation away from the bottom of the roof. When in contact it makes that part of the roof colder and any humidity that seeps through the insulation forms moisture and ice.

Yes, that should help.

Bud
 
  #12  
Old 01-15-16, 10:46 AM
S
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 19,125
Received 1,263 Upvotes on 1,204 Posts
I'm nit-picking, I know, but it can be a source of confusion - you're proposing moving the insulation to the floor, not the ceiling; each is based on a source of reference and we have not left the attic so this is the floor of the attic and the ceiling is the rafters from which you propose to remove the insulation.
 
  #13  
Old 01-15-16, 11:36 AM
A
Member
Thread Starter
Join Date: Aug 2010
Location: USA
Posts: 388
Received 2 Upvotes on 2 Posts
Correct.

Remove from between the roof rafters beneath the decking and install on top of current insulation that is already located in the ceiling of the second story.

As for the baffles, the objective of air flow isn't to just move the air from intake to exit, it is to remove moisture and heat from the bottom of all rafter cavities. They recommend every rafter bay.
Ah. I see. These rafter cavities literally open up to the porch attic which is wide open to the soffitt. I only suggested every other one because the insulation currently in there does NOT touch the roof deck anywhere, so there is at least a little air gap for which air to move. Or at least, that's how Im reasoning this out in my mind.

I want to add as many as is economical. They are very expensive though, as is insulation, and Im pretty sure that Im not going to realize much of any return for several years. Thats why Ive put it off so long.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: