Shed Roof Thermal Relief for Winter/Summer

[Don2222]

Hello

To prepare for the warmer weather and also keep the cold from escaping right now it is a good time to put in the Shed Roof Thermal Relief system from el cheapo home depot or Lowes.

Save heat escaping in the winter and stop the sun's rays from penetration in the summer!

Just some Reflectix foil over black plastic rafter vents from the soffit vents to the ridge vents.

This will also prevent any ice dams in the winter!

Since the rafters are 2x6 then should I add insulation over the foil??

See pic below

 

[SmokeyTheBear]

That should make normal pellet stove testing rather short or in the alternative you'll need lessons in escaping high heat zones.

 

[Don2222]

Hi Smokey

Yes, well we are striving for better energy efficiency so actually this is a test for doing that. The Quadrafire Classic Bay was really short cycling even with a 3 "Swing setting" in the cold winter with no insulation! The T-Stat was at 70 Deg F and just when the stove finished the shutdown cycle it would start right back up again. So that was not a very realistic home test scenario. I do admit that extreme condition like that can easily shoe up any problems!! However it will be interesting how all of this will effect the Auto On/Off cycle and I really do hope to make that as long as possible

So my question was about adding say some Lowe's Johm Mansfield R15 Fiberglass between the cathedral roof rafters? See yellow arrow in pic. Click pic to enlarge

 

[SmokeyTheBear]

Go for it Don, did you actually try a pellet stove in there after after insulating most of the place?

Don't forget to do something about your windows and doors while you are at it. Maybe make a couple of mesh, soda can, or aluminum downspout hot air solar collectors to help the stove.

 

[begreen]

Did you try relocating the thermostat?

 

[SmokeyTheBear]

begreen, I don't think Don has had a stove in there since he sold the CB1200 which was short cycling and at that time the shack wasn't insulated.

 

[711mhw]

the foil might create a moisture barrier that should be closer to your heat side (on the other side of the insul.) You will prolly get wet insulation. Most things that I read, and have heard, really call the foil/bubble deal a hoax.Check out, http://www.greenbuildingtalk.com/Forums.aspx for some smart folks there about insulation.
And Smokey, Ya ever run maple sugar thru a still or did something like you'd do with wine? It is that time of the year, and I'm not far from you and it's been a while since I've had any good "squeezins"!

 

[SmokeyTheBear]

the foil might create a moisture barrier that should be closer to your heat side (on the other side of the insul.) You will prolly get wet insulation. Most things that I read, and have heard, really call the foil/bubble deal a hoax.Check out, http://www.greenbuildingtalk.com/Forums.aspx for some smart folks there about insulation.
And Smokey, Ya ever run maple sugar thru a still or did something like you'd do with wine? It is that time of the year, and I'm not far from you and it's been a while since I've had any good "squeezins"!

Can't legally run wine through a still in the US without the hassle of obtaining a distiller's license, keeping books, and paying the tax man, except for fuel production and that stuff has to be accounted for and poisoned.

Tempting yes, but I don't need the hassle so I stick with what is permitted.

The bubble wrap foil crud isn't a real good insulator if you talk conduction, better at the radiation side and for that you really don't want to cover it. Don somewhat already has vapor barriers on both sides of that R15 stuff and as a result, it isn't likely he'll get much in the way of condensation in his fiberglass stuff.

 

[smoke show]

Next project: Skylight to channel heat out.

 

[SmokeyTheBear]

Next project: Skylight to channel heat out.

Or pump installation to dewater his shed ceiling.

 

[Don2222]

Hi BeGreen
Yes, Smokey is right, I have no stove so I am insulating right now before another one comes in.
Before the T-Stat was located in the opposite corner as far away as possible but it still short cycled.

To 711mhw

You are correct that most of the time the poly covered foil should be on the warm side. In walls it is usually done that way.

A roof is a little different. In the house I had it over the rafter vents but it was in a cold zone in the winter time because all the insulation was in the attic floor.
In the summer time the foil stopped the sun's heat dead before it entered the attic!! Works great!!

The shed has a cathedral ceiling which like in a house is very different!!
Normally insulation is applied over the rafter vents and then a sheet rock ceiling over that. That does not stop the sun's heat in the summer and the room gets very hot!! It is not a total solution

So I am trying to achieve the total solution by installing the rafter vents and the foil over the vents. Now if I put insulation over the foil then the foil will be in the cold area in the winter. That should work fine like in the house. In the summer it will also stop the sun's rays dead and the shed will be cooler!!

Again, I could add more foil over the insulation, like I did with the house. In the house the foil was installed under the insulation in the attic floor. That keeps the warm heat inside the house in the winter!! As far as the shed goes, this may be overkill !

 

[nate379]

I would put up a good vaporbarrier between the vent and the insulation... might be worth using only R13 (2x4 insulation) so it's not touching the roof. I'm not sure how well that foil works for anything other than as packing material...

 

[Don2222]

Go for it Don, did you actually try a pellet stove in there after after insulating most of the place?

Don't forget to do something about your windows and doors while you are at it. Maybe make a couple of mesh, soda can, or aluminum downspout hot air solar collectors to help the stove.

Hi Smokey
The door is a 48" wide steel insulated utility door by Farmtek in Ohio. The Window is a double hung double glazed vinyl and aluminum clad from Habitat Homes Restore for $30 dollars!

I just started the insulation. The back wall is done but did not seem to make much difference in holding in the heat with the other 3 walls not done yet. I got the roof 3/4 done with the foil and rafter vents and I noticed a huge difference already. Currently it is 38 Deg F out and 52 in the shed.

So it seems that the roof was leaking heat like a siv!! That is where the most bang for the buck is!

 

[Don2222]

I would put up a good vaporbarrier between the vent and the insulation... might be worth using only R13 (2x4 insulation) so it's not touching the roof. I'm not sure how well that foil works for anything other than as packing material...

The foil has 2 layers of plastic one on each side up against the rafter vents. The insulation will go on top of that.

As far as the foil goes, I am amazed at how well it works here in Salem NH. Down south it is used so much they have contractors that just install foil and nothing else!!

 

[Don2222]

Hello

Well got some R13 Fiberglass in on top of the foil. Used those round coat hanger type of supports. See picture below.

Those supports seem very clunky. Does anyone know of any better supports??

 

[nate379]

Unfold the edges and staple it to the truss.

 

[DexterDay]

Unfold the edges and staple it to the truss.

X2... Only way I have done it (if your not covering with drywall or any other board).

 

[smoke show]

Unfold the edges and staple it to the truss.

x3

 

[SmokeyTheBear]

+1

 

[Don2222]

Yes, I have to get more staples for the air gun!!

 

[Don2222]

Hello

Thanks Guys about the stapling. I just did it today!
The problem was:
I ran out of 1/2" crown 3/8" long staples and Sears and NoOne else has them anymore!
So I returned the Air Stapler to Sears and got my $129.00 back.
Then I ordered a 3/8" wide crown 3/8" long air staple gun from Northern Tool on sale for $19.95
http://www.harborfreight.com/20-gauge-wide-crown-air-stapler-68029.html

Then went down to the local NH Tool Supply and picked up 5,000 3/8" Crown 3/8" Long staples for a Slap Stick.
http://www.nhtoolnsupply.com/

A Slap Stick is for stapling TyVek to the side of a house!

Worked out great! All done now see pics. Thanks again for the great advice!

Without staples, the fiberglass was falling out!
With staples it is sealed up!

 

[Don2222]

Go for it Don, did you actually try a pellet stove in there after after insulating most of the place?

Don't forget to do something about your windows and doors while you are at it. Maybe make a couple of mesh, soda can, or aluminum downspout hot air solar collectors to help the stove.

Hi Smokey

Well I finally tried the Pelpro I am working on yesterday in the shed that now has some more insulation. But first I had to run out and exchange that Lux DHM 110 T-Stat for the TX-1500 U. See > https://www.hearth.com/talk/threads/wood-pellet-stove-t-stat-for-shop-or-home-finally.86223/

So with the Swing Setting on # 8 that is a 2.0 Deg F swing and the T-Stat set to 70, it was 43 Deg F outside. I insulated the ceiling and the back wall behind the wood pellet stove. One cycle took about an hour. So 0.5 hour off and 0.5 hour on heating from 60 to 72 Deg F. Then off when falling from 72 Deg F to 68 Deg F.

So I was a little disappointed that the warm air would not stay in the shed longer on this somewhat mild night. It was windy and drisly so that did not help. So when I do the other 3 walls I am hoping that the results will be much better?

What do you think?

 

[Don2222]

Hello

Well, one of my neighbors gave me some Dow Tuff-R foam board with foil on both sides that is R6.5 and 1" thick.
See > http://www.homedepot.com/h_d1/N-5yc...ord=TUFF-R&storeId=10051&superSkuId=202939003

So I cut it into 2 triangles for the inside of the shed up near the peak.

We had to cut the protruding nails with the Dremel Cutting wheel first. Then cut the foam so the small piece could be pushed in behind the electrical junction boxes.
Will this help? What is the best way to fasten it to the inside plywood or studs? How should I fill the tiny space near the top 2x6 rafter board? See pics below:

 

[shtrdave]

Don,

Why not hold it in place with a nice bead of silicone caulk around it, this would also fill in any gaps that may cause drafts.

 

[Don2222]

Don,

Why not hold it in place with a nice bead of silicone caulk around it, this would also fill in any gaps that may cause drafts.

Thanks, That's a good idea. I was thinking of that expanding foam too.

I also tried foil tape and stuffing the edge with some left over fiberglass insulation.