Seeking Advice on Attic sealing and upgrade


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Old 08-09-13, 10:03 AM
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Seeking Advice on Attic sealing and upgrade

My house is located in Roanoke Va. and was built in 1926. It is a brick faÁade foursquare type home with a full walkout basement and a walk up attic (stairway up to attic). I am capable of doing most any type handyman work. I have worked as a carpenter, Brick mason and now as an electronics technician. There is very little I wonít attempt to do myself.
The attic is where my concern lies for this post. I am in the process of air sealing and adding insulation to the attic. I am posting a sketch drawing I did of the soffit area and my intended plan of sealing along the top of the walls.
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I also think I need to add another piece of foamboard / great stuff vertically between the soffit and the rafters as a dam for the blow in insulation to keep it out of the soffits, yet spaced so there is an air gap between the rafters and the soffit. Attic foil will be attached to bottom of rafters all the way to top of roof.
Currently I have some type of 3-4 inch old style batts (Superfelt I think is the brand name) with about 2 or so inches of loose blow in. I want to blow in enough to get to around R-50 or so.
Now the walk up area has a floor and a dormer window. Itís used for storage of various decorations, extra furniture, seasonal clothing and such.
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The air handler for the upstairs AC is also mounted here. There are no soffit vents and as itís a hip roof construction no ridge or attic vents of any kind except by using the window. There is a roof ridge of about 6 feet.
Should I install soffit vents and a solar vent fan?
I have plans to build a foamboard plug to cover the stairwell once the insulation project is complete. My concern is how to insulate but maintain the storage area. Should I frame it out and create an area separate from the heavily insulated area? If so do I use foam board in the rafters (again leaving an air space between sheathing and insulation) .The floored area is about half of the area if the entire attic. ~1150 sq/ft. There is insulation under the floor already but again itís the old product. How should I address the floored area?
Oh and I have knob and tube to deal with as well. I think Iím probably going to upgrade that before the blow in. ( local inspector said I didnít have to but I think itís a good idea before superinsulating)
 

Last edited by Frank_S.; 08-09-13 at 10:22 AM. Reason: Add pix
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Old 08-09-13, 03:16 PM
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A ridge vent and adding soffit vents should be done first.
A solar vent in my option is about useless. Does not remove enough air, leaves air trapped in the rafter bays, useless at night, looks ugly. A ridge vent cost nothing to run, is not going to stop working, almost can not be seen, vents all the bays.
There's 0 need to do anything between the rafters for insulation. Just need plastic or foam baffles to keep the new insulation from blocking the flow of air from the soffits to the ridge.
There's also no need to seal at the top of the brick veneer.
 
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Old 08-10-13, 04:58 AM
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With this being a hip roof design I only have a 6 foot ridge too vent.
I do not think that is enough area for the 1/300th design guide for ventilation that's why I was thinking of a powered fan.

I also am thinking the air sealing is more important for heat loss ,which is when my power bills are highest.
Cooling is important but the house hasn't had "proper" venting since 1926.
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Old 08-10-13, 09:18 AM
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Welcome to the forums!

Air sealing, sufficient insulation and ventilation to keep the insulation dry and effective are all important in reducing your heating costs. So is a well-maintained heating system.

R-50 on the attic floor is probably overkill for Roanoke. You can enter the information for your house in the ZIP-Code Insulation Program to determine the optimum amount of insulation you need to add.

Install a continuous soffit vent. Install the ridge vent. Since you have a hip roof, install hip ridge vents such as the Hip Ridgeģ Vent from Air Vent. Don't install any fan. Don't install anything on the rafters. Don't bother sealing the tops of the walls - moisture needs to get out of them. You can install hardware cloth at the edge of the attic to keep loose insulation from blocking the soffit vent, while maintaining air flow at the same time.
 
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Old 08-10-13, 01:42 PM
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It is best to have a top vent at the brick, and not send any moisture to the attic. Foamboard vertically, flush with the outside sheathing boards- leaving a gap if vented soffit later. Is adding air holes to the brick mortar something you can do; height accessibility, etc.? Could you install a screened slot in the trim board -existing now at top edge of brick, keeping any extra moisture from the soffit cavity (where air is incoming to attic). Fig.5; BSD-105: Understanding Drainage Planes — Building Science Information

Early New Jersey study of attic moisture; Moisture Control in Buildings - Google Books

Your climate is similar to mine; Climate Information for Roanoke*-*Virginia*-*Mid-Atlantic*-*United States*-*Climate Zone

And we have thousands of roofs without soffit/ridge venting on older houses, still standing; Climate Information for Seattle C.O.*-*Washington*-*West*-*United States*-*Climate Zone

Ventilation need should be examined per location; http://www.fpl.fs.fed.us/documnts/pdf2002/rose02a.pdf

Ice-dams, insulation, moisture control without ventilation; dormers and HVAC in attic: BSD-102: Understanding Attic Ventilation — Building Science Information

Have you researched hip-ridge vents at all, or closed unvented attics?
Are you showing signs of mildew on sheathing boards, rafters, etc. that would merit adding more ventilation for moisture control?

Gary
 
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Old 08-10-13, 09:07 PM
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Unhappy

Gary can you show me using my sketch where you think the foam board should be? My concern is the top portion of the interior walls are left kind of exposed to the incoming breeze and I thought the idea was to air seal around the walls to either limit air entry and/or guide it so that it works for us so I'm a bit cornfused.
Maybe I don't need to add vents...

Nashkat1 -So you think I should use hip vents and install hardware cloth as a dam to keep the blow in out of the soffits. Do you know where I can get ridge vents in Roanoke area?

Maybe I misunderstood and the airsealing just needs to be done more inside the structure.
How should I approach the "finished" floor area where the air handler is as far as insulating further? DO I build it all in and insulate it like a room or just insulate around the floored area and hope for the best? What a can of worms wanting to lower the electric bill opens.......
 
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Old 08-11-13, 08:22 PM
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Gary can you show me using my sketch where you think the foam board should be?
If I understand him correctly, Gary is suggesting installing 1" XPS vertically above the frieze board - just to the right of the arrow pointing to the "1" foam cap" in your drawing. He's more-or-less saying you should turn that piece of foam up on edge.

Maybe I don't need to add vents...
You definitely need to add vents. It's either that or a sealed ventless attic, and I think your house will be more comfortable with the vented attic.

So you think I should use hip vents and install hardware cloth as a dam to keep the blow in out of the soffits.
Yes. Gary suggested the hip ridge vents also.

Do you know where I can get ridge vents in Roanoke area?
No. I haven't even visited the Star City much in nearly 20 years, and I never lived or worked there. Ridge vents are common as dirt. As for the special vents for hip ridges, I would think any good roofing supply house would either carry them or be able to get them pretty much overnight. Did you follow the link I gave you? Air Vent lists nearly 30 dealers on their site.

Maybe I misunderstood and the airsealing just needs to be done more inside the structure.
Yes. It's at least as much about managing moisture movement as it about slowing any convectional heat loss. The goal is to retard the amount of moisture that gets into your walls and ceiling, and to evacuate what does get there as effectively as possible.

How should I approach the "finished" floor area where the air handler is as far as insulating further? DO I build it all in and insulate it like a room or just insulate around the floored area and hope for the best?
How deep are your joist bays? What R-value did the ZIP-Code Insulation Program give you for your attic?

I would be inclined to install a dense material like mineral wool batts under that floor. Building a finished, insulated room there will be expensive, hard to do, and not very effective.

What a can of worms wanting to lower the electric bill opens....
Your electric bill? What kind of heating system do you have?
 
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Old 08-11-13, 09:25 PM
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"Gary can you show me using my sketch where you think the foam board should be?" --------------------------- Any of the diagrams at the end of article, here: http://www.buildingscience.com/docum...ifornia-attics

"Maybe I misunderstood and the airsealing just needs to be done more inside the structure."------------------------------------------------ http://www.google.com/url?sa=t&sourc...wWATQw&cad=rja

Add a floor: Fig.15 and read pp. 23-24, here; http://www.buildingscience.com/docum...ation-packages

Foam board, with/without baffles in vented and unvented attics, Figs. 4,5, in link above. You could install baffles for future openings in soffit, your call.

Gary
 
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Old 08-12-13, 04:23 AM
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Thanks Gentlemen for your responses.
NAshkat- I did follow the air vent link but I didnt recognize any of the names listed as dealers. And yes I have an electric boiler circa 1962. Made by Electro Pak It has 4 5kw heating elements 2 come on when heat is called for and then 30 seconds later the other 2 come on. They stay on until heat is no longer called. I am trying to update the heating system with a new control board that will modulate the heating elements according to the outgoing water temperature. I can do this for less than 500.00 if I can get the parts. I intend to try that this heating season and if that doesn't cut it I may look into a natural gas boiler.

The floored area has 2x6 joists with a layer of Super felt- some kind of faced black insulation product further enhanced with blow in then the 3/4 T& G boards on top.
Gary Thank you for the links.
 
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Old 08-12-13, 10:18 AM
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By the way Nashkat I could not get the Zip code calculator to work. It got all the way to asking what I wanted to insulate and it said please wait for 20 minutes before I canceled.
 
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Old 08-12-13, 03:21 PM
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That's frustrating. I know because I had the same experience when I tried. It may be Java, but when I tried replacing that my browser died. So I couldn't run it either.

I have an electric boiler circa 1962. Made by Electro Pak It has 4 5kw heating elements 2 come on when heat is called for and then 30 seconds later the other 2 come on. They stay on until heat is no longer called.
If I were you I would put all of my insulation and ventilation money in a safe place and start calling HVAC contractors. Electricity is probably the least efficient energy source for making heat that we have, and natural gas is one of the most efficient.

Consider this: Since Roanoke has more than twice as many cooling degree days than heating degree days each year, should your electric bill be higher in the winter or in the summer?

Ask your friends and neighbors for referrals. Contact Roanoke Gas for information about subsidies/rebates and their list of approved contractors. They may have package deals available to lower the cost if you change out the boiler/furnace and add insulation and weatherstripping at the same time, for example.

Listen well and talk little. "Just the facts, Ma'am." Let us know what you learn.

BTW, another member here just opened a thread about insulating his roof or attic. He lives in Northern Ontario, and R-50 is the recommended value there. Yours should be no more than R-40 at the most.
 
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Old 08-13-13, 06:09 AM
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From what I saw on Climate zone .com site it looks like Roanoke has 4360 heating degree days VS. 1052 cooling days so I guess that jives with my bill being 4 times as much in winter as summer.

8/8/2013 2,062 KWH $233.50
7/11/2013 2,329 KWH $262.14
6/11/2013 2,046 KWH $231.71
5/10/2013 1,867 KWH $202.53
4/10/2013 4,639 KWH $487.01
3/12/2013 6,394 KWH $682.38
2/8/2013 5,857 KWH $627.68
1/11/2013 6,179 KWH $662.23
12/10/2012 4,973 KWH $535.23
11/7/2012 3,389 KWH $368.44
10/9/2012 1,734 KWH $193.72
9/10/2012 2,521 KWH $289.86
8/8/2012 2,237 KWH $258.51
7/11/2012 2,643 KWH $295.36
6/8/2012 1,789 KWH $195.54
5/9/2012 1,848 KWH $191.79
4/11/2012 2,026 KWH $209.30
3/9/2012 4,315 KWH $427.03
2/10/2012 5,174 KWH $488.40
1/11/2012 5,512 KWH $492.81
12/9/2011 3,797 KWH $343.03
11/8/2011 2,831 KWH $258.72
10/10/2011 2,042 KWH $189.56
9/8/2011 2,185 KWH $213.45
8/9/2011 2,187 KWH $213.64
7/12/2011 2,029 KWH $199.05
6/10/2011 1,558 KWH $155.54
5/11/2011 1,580 KWH $148.97
4/11/2011 3,489 KWH $316.14
3/11/2011 4,489 KWH $403.44
2/10/2011 6,355 KWH $566.35
1/12/2011 8,434 KWH $787.51
12/9/2010 5,760 KWH $556.30
11/5/2010 1,929 KWH $193.65
10/11/2010 1,887 KWH $189.65
9/9/2010 1,651 KWH $176.14

I will Call Roanoke Gas.
 
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Old 08-13-13, 10:51 AM
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Glad you saw that, also. You are under 2009 energy code; Virginia Building Codes

R-38 minimum is required; 2009 IECC Climate Zone Map - Virginia

If you have high ceilings (similar to four-squares), may want more R-value, though there is a cost/value break point where money can be spent better elsewhere; http://www.google.com/url?sa=t&rct=j...,d.cGE&cad=rja

Gary
 
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Old 08-13-13, 12:15 PM
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From what I saw on Climate zone .com site it looks like Roanoke has 4360 heating degree days VS. 1052 cooling days...
That makes more sense, so I double-checked. It turns out that I hadn't read something carefully enough. The information in the ZIP insulation program actually said about 4300 heating degree days and about 9300 cooling degree hours. I have no ides why they stated them differently, but there's probably a reason. So that's the same value for heating and only 387.5 for cooling, if you divide 9300 by 24. I'd go with the ones you found.

I will Call Roanoke Gas.
I think that's likely to lead to a better return on investment. If it turns out that converting your heating now is a better idea, you'll have the "less than $500" for the upgraded control board to put toward it too.

Tell us what you learn there and we can continue with the insulation and ventilation discussion.
 
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Old 08-19-13, 08:56 AM
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I am making some headway in the beginning of my attic insulation project I have almost 3 sides along the soffit edge completed, Its a slow process as I am working alone and have to measure the opening , cut the material then go back and fit it in place. Then come back in and spray foam it once I am done for awhile to allow it to cure.
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I also found this opening above the closets in 2 of the bedrooms. It was cover over only with insulation. I am sealing it all in with foam board and great stuff then I'll put the insulation back in place. While the opening was there I went ahead and put in a couple of receptacles in the bedrooms and dropped wiring in which I'll hook up later. I figured it was easier to fish it down now rather than later. You can also see that Knob and tube which will be removed and new runs of romex installed.
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I also attached a picture of the insulation installed beneath the 2 inch of blow in. It turns out that the Super Felt is a rock wool insulation.

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