cathedral insulation rant

dug · December 01, 2010, 06:08:36 PM

Well it is somewhat of a rant but I thought I'd pass on some info I have learned today to anyone who may be insulating with batts soon.

I am not sure anyone here in the SW vents their cathedral ceilings because I have spent 3 hours on the phone today trying to track down baffles everywhere from Tucson to El Paso and no one (almost) had any idea what I was talking about, they had never heard of them, never stocked them, never would, and doubted their existence. I was hung up on 3 times, once by the big cheese at the local building supply. I did finally talk to someone at a HD who knew what I was referring to informed me they had 50 in stock. Not enough, and too far away but I got the part # and called back the indignant cuss who hung up on me earlier at a closer HD and gave him the part # and lo an behold they were in their system.

They had none but could bring them up from El Paso in 3 days.

HD part #- 536267 / 4 ft. by 22 in., $1.78 ea.

I picked up my R30 ceiling insulation at Lowes (don't even talk to me about R30c because I have been assured multiple times that does not exist) and they have a deal now where if you get $700 (might be $800, I forget) worth of their insulation you get a $200 gift card. That, combined with a 10% off coupon available at any federal post office (look for the moving kit envelope) made for a pretty good deal. Since I can only fit so much in my mini van anyway I'm going to split it into 3 orders and pick up $600 in gift cards. The insulation is formaldehyde free and does seem a lot friendlier on the skin than the pink stuff.

Redoverfarm · December 01, 2010, 07:36:25 PM

Dug not real sure of what your rafter bay will be demension wise but if it is 16"OC you can split most of the air baffles ( made to seperate) and you would only need 1/2 of the total amount if you figured on a complete baffle per bay.

December 01, 2010, 08:47:48 PM

I guess Lowe's and HD both were uninterested in ordering the "C" type batts.

This will not help the present discussion or search for an answer, but may be useful to someone else down the road.

One way to get around this venting problem is to do away with the need to ventilate. That can be done with an layer of foam sprayed on the underside of the roof. It can also be achieved by installing a layer of rigid foam over the sheathing and under the roofing material. Either way the rafter cavities are fully packed and not vented.

INFO That's at buildingscience

dug · December 01, 2010, 09:38:38 PM

QuoteDug not real sure of what your rafter bay will be demension wise but if it is 16"OC you can split most of the air baffles ( made to seperate) and you would only need 1/2 of the total amount if you figured on a complete baffle per bay.

It's 24 centers. Just listened to a phone message and it was HD saying that El Paso had 140, but would only ship 50 to the closer HD (I need 105).

Back to the drawing board.

QuoteI guess Lowe's and HD both were uninterested in ordering the "C" type batts.

One location informed me they did not exist, the other said they would not order them. Live and learn.

Erin · December 01, 2010, 10:52:19 PM

Well I can find baffles easily enough, but I called four lumber yards before I managed to find 2x6 T&G.
"Ma'am, I think you mean 1x6..."

So I can sympathize anyway.

December 01, 2010, 11:30:15 PM

Thats is sort of hard to believe if they have them in stock that they will not ship the quanity that you request. Maybe it might pay you to call the "home office" and explain the delimia and see what they have to say about it. They are pretty common here and most lumber yards carry them or their equivalent. I have in the past run short on the baffles and used 1"X1" and 1/2" styrofoam sheeting to create my own but it is a little more costly. I think the last ones I bought were just about $1. Shoot it might pay to order elsewhere at a good price and have them shipped to you.

dug · December 02, 2010, 12:05:50 AM

Yeah I found it hard to swallow also, I was kind of speechless when she informed me of that. I'm calling back in the AM. Maybe I will do some cyber-shopping and see if I can't land a better deal.

Erin- I played the same ring around the rosey game with the T & G too! I can relate to the frustrations coming from the retail end, I was in retail for many years, but one thing I learned is that sometimes the customer does know something you don't and I always assumed they were right until I found out for sure otherwise.

dug · December 02, 2010, 03:07:31 PM

The trouble goes on. El paso has them, but I can't get anyone in the Las Cruces store to believe it. Two more hours of wasted phone tag, still waiting for call back.

Have not been able to locate an online source.

I was thinking of just building my own using 1/2 styrofoam board and nailing up furring strips on both sides of the rafters in order to attach the board. It would cost about $100 more, and would involve extra labor but at least I think I could get it.

Would that work O.K.?

I know you might think I am making this up, but here goes... Just picked up phone- Dude at Las Cruces pro desk: What was the SKU # on that durovent you wanted? I had already given him the number (twice!) and the name of the product, but calmly opened another window, dialed up their site and read him the number. I had already confirmed by phone the quantities available at all three El Paso locations and am only trying to see if they can pull them from there, something they normally do no problem. Also this was the same guy who just assured me this morning that none of the regional locations including El paso stocked them and I could only order them in bundles of 70 each, which is why I called El Paso myself and related the (correct) info to him!

MountainDon · December 02, 2010, 03:24:00 PM

Hmmm, there's about 400 of them listed at the 4 Lowe's closest to me.

also interesting is this PDF doc.. Leave a space between raftermate ends...

http://roofing.owenscorning.com/docs/raftrmate/Unheated_Attics.pdf

December 02, 2010, 03:27:56 PM

FWIW

http://www.amazon.com/Owens-Corning-10-Raft-r-mate-22-5x48/dp/B000QSEMKU
http://www.amazon.com/Ado-Products-UPV14480-ProVent-Attic/dp/B0038RDNBU/ref=pd_sxp_grid_pt_0_1
http://cheapatticventssale.cz.cc/attic_rafter_vents.html

also chaeck ace hardware, free delvy to stores

MountainDon · December 02, 2010, 03:40:39 PM

Quote from: dug on December 02, 2010, 03:07:31 PM

I was thinking of just building my own using 1/2 styrofoam board and nailing up furring strips on both sides of the rafters in order to attach the board. It would cost about $100 more, and would involve extra labor but at least I think I could get it.

Would that work O.K.?

Using half inch plus furring strips would mean you'd really be compressing that R30 insulation. Might negate any R-value gain from the foam board.

It almost seems if you were going to do all that labor it might be worth thinking about installing well fitted one inch foam board between the rafters and right against the sheathing.

That would be a pain in the butt as far as I am concerned, and it would have to be sealed perfectly, but it would remove the cold surface where condensation would take place. Of course the R30 would be too thick for that as well.

dug · December 02, 2010, 04:09:47 PM

QuoteInsert Quote
Hmmm, there's about 400 of them listed at the 4 Lowe's closest to me.

Lowes here gave me the same statement that HD did, which was that they could order them in bundles of 70 (I take all) and they were .40 more apiece.

I have to literally clean out 2 of the 3 stores in El Paso to get the 105 I need!

Just checked your most recent post Don and feel pretty dumb for not being able to find those. Guess I'll check Amazon for everything from here on out. I can get 140 of them from Toby's Tool Shed for about $185 including shipping. Cheaper than HD and I'll have 35 extra to account for miscalculations.

Thanks!

das fisch · December 02, 2010, 04:31:37 PM

Quote from: MountainDon on December 02, 2010, 03:24:00 PM
also interesting is this PDF doc.. Leave a space between raftermate ends...

that is interesting, I've never heard that one before, i've always overlapped the ends a bit.

Txcowrancher · December 02, 2010, 04:37:51 PM

Hey Dug
Im at the same stage as you I guess on the venting/insulation. on my shed roofs with no venting I had sprayed about 3 inches of closed cell foam and now I am trying to decide on insulation for the rest of the 2x12 space.
did you get the non-fiberglass from lowes? I think its called safetouch, I checked and it was about the same as the denim, right at twice the cost of fiberglass.

anyway which way did you go? with that 200 dollar gift cert and 10% I might get the good stuff
thanks
Tom

December 02, 2010, 04:55:39 PM

Quotedid you get the non-fiberglass from lowes? I think its called safetouch

I thought that is what they had there but they stock only the formaldehyde free fiberglass that is made by the same company, at least where I am. It is about the same price as the stuff at HD, before the discounts. I would think they should be able to order the safetouch, but I wouldn't attempt it here!

Redoverfarm · December 02, 2010, 05:10:04 PM

Quote from: MountainDon on December 02, 2010, 03:40:39 PM
Quote from: dug on December 02, 2010, 03:07:31 PM

I was thinking of just building my own using 1/2 styrofoam board and nailing up furring strips on both sides of the rafters in order to attach the board. It would cost about $100 more, and would involve extra labor but at least I think I could get it.

Would that work O.K.?

Using half inch plus furring strips would mean you'd really be compressing that R30 insulation. Might negate any R-value gain from the foam board.

It almost seems if you were going to do all that labor it might be worth thinking about installing well fitted one inch foam board between the rafters and right against the sheathing. That would be a pain in the butt as far as I am concerned, and it would have to be sealed perfectly, but it would remove the cold surface where condensation would take place. Of course the R30 would be too thick for that as well.

Don I measured a piece of vent that I had at the house and it has a projection of 1.5" so it would basicly be about the same as 1" furring and 1/2 board with the compaction of the insulation.

MountainDon · December 02, 2010, 05:31:42 PM

Another thought, not sure how good. Nail/screw furring strips on the rafter edge facing down. That gives more space for the insulation and maybe enough free space above the insulation.

You might have to cut your own strips to make them thicj enough to do the job without needing the pro-vent/dura-vent....

Those would have to be secured well enough to hold the ceiling weight or the ceiling would have to be fastened through to the rafter.

MountainDon · December 02, 2010, 06:23:32 PM

Quote from: Redoverfarm on December 02, 2010, 05:10:04 PM

Don I measured a piece of vent that I had at the house and it has a projection of 1.5" so it would basicly be about the same as 1" furring and 1/2 board with the compaction of the insulation.

I guess I had forgotten how thick they are. Even they would be compressing the insulation a lot and now I wonder if they would be flattened by the pressure from compressed insulation over time.

I have no idea, just wondering.