A Frame Insulation

[Tradecraft]

Gentlemen,
First post--I am a remodeler in South Arkansas. I have been in the trades for a little over 7 years. I recently left a rotational oil field job in Saudi Arabia to remodel full time. My company is two months old and thriving. I hope that is enough info to not get me run out on a rail. I've seen that a few times over the last three months.
I have a customer who recently purchased an A-frame foreclsoure. The 22 on 12 pitch house was built in 1977. The wall/ceiling stucture, from the inside-out is 1x SYP tounge and groove, 1/2" black board insulation, 3/4" sheathing, 30 lb paper, 15 year old shingles. The customer is a former real estate broker and was able to access the utlility history for the house. There were some obvious efficiency issues with the 45' tall structure. The customer is hell bent on roofing over with a metal roof and wants to add a layer of insulation. Can anyone suggest a solution to this challenge? Any help is greatly appreciated.

[gsproule]

Re: A Frame Insulation

Well, I am certainly no expert, but here is what I would suggest. Strip the shingles, then add the desired amount of foam insulation, two layers would be best, taped at all seams and sealed at the edges...might as well add as much as you can afford, if you are going to go to all this work.... On top of the foam, add vertical 1X4 strapping on 2' centers, using long screws if necessary. Next, add another layer of strapping on the horizontal, again on 2' centers. Add metal roofing and make sure that air can flow easily under the roofing by adding screened venting top and bottom.

Good luck
Garth

[Riversong]

Re: A Frame Insulation

I hope that is enough info to not get me run out on a rail.

Thanks for the introduction. Welcome to the forum.

The wall/ceiling stucture, from the inside-out is 1x SYP tounge and groove, 1/2" black board insulation, 3/4" sheathing, 30 lb paper, 15 year old shingles.

There's no framing? And by "blackboard, I assume you mean semi-rigid fiberglass boards?

The customer is hell bent on roofing over with a metal roof and wants to add a layer of insulation. Can anyone suggest a solution to this challenge? Any help is greatly appreciated.

You make it sound as if you don't approve of the customer's choice. Why not and what do you see as the challenge?

[rustyjames]

Re: A Frame Insulation

Another option is to go with a concealed clip standing seam metal roof system where the clips sit on bearing plates. I've seen this done over 5" of board insulation (2 layers 2-1/2"). That's a common application in commercial work.

[calvert]

Re: A Frame Insulation

Tradecraft, How much snow do you get on average?

[Tradecraft]

Re: A Frame Insulation

Thanks for the introduction. Welcome to the forum.


There's no framing? And by "blackboard, I assume you mean semi-rigid fiberglass boards?

The t & g is laid on lam beam rafters on 6 foot centers--approx 45' long to the ridge. The t&g is exposed to the inside.


You make it sound as if you don't approve of the customer's choice. Why not and what do you see as the challenge?

No, No, It's not that I don't approve. Aesthetics only. I just happen to love shakes. I certainly did not mean to make it sound like I did not approve. Consider me a little green, but I am also assuming that the "black board" is semi-rigid fiberglass. I do know that it is not used around here anymore and I have not seen it in any of our lumber yards. Would you happen to know the R-value on the Semi-rigid fiber board? The "challenge" is simply a substitute term for what I think is a problem--that is, a very innefficient system. I am just not up to snuff on all of the technological solutions for sound energy efficiency and insulation. Also the 'challenge' could be interpretted as having to rig up and lay 45' sheets of metal roofing, but that's all in a days work, right?

We have a local product that is, for all intents and purposes, a SIP. This particular product is a corrugated metal on one side, 4" foam, 26 gauge flat metal on the bottom side. I am thinking this could be a viable solution to his energy woes. Could this be laid directly on the sheathing, or rather the felt?

[Tradecraft]

Re: A Frame Insulation

1/2"--no accumulation.

[Riversong]

Re: A Frame Insulation

The blackboard is made for acoustical separation or for fabricating ducts. It probably has about R-4/inch, so only R-2 for a ½" board.

You haven't answered my question about whether there's framing in the roof assembly. You didn't list it in the cross section.

[David Meiland]

Re: A Frame Insulation

Man, what a brutal job that will be. Go up the roof once to install new insulation board, felt, and purlins, then go up again to install the metal. It'll make oilfield work seem easy.

[Riversong]

Re: A Frame Insulation

JLC users--48.5% likely to bounce!

OK, what the heck does that mean?

[David Meiland]

Re: A Frame Insulation

My website has Google Analytics code on it, which lets me look at who visits, where they come from (in some cases they come from here) and what they look at. "Bounce" means someone does not go beyond the front page. Good thing I don't need to sell any of you guys a job.

[davenorthup]

Re: A Frame Insulation

Man, what a brutal job that will be. Go up the roof once to install new insulation board, felt, and purlins, then go up again to install the metal. It'll make oilfield work seem easy.

Sounds steep enough that if you can get a lift in there - would be pretty easy. Better than sitting in a harness days on... :)

Make sure you can get a 45' panel of metal. I can not get one that long here; but you might - otherwise you gotta overlap.

[Lavrans]

Re: A Frame Insulation

Well, from personal experience I can tell you that it would be a bad idea to install craft-faced bats of insulation between the rafters and leave it uncovered. Bees like to live in insulation. Add in a 40' tall stovepipe that isn't flashed properly and has rusted out in spots may very well lead to a fire starting.

Strangely enough, it doesn't take long for fire to travel down an A-frame to the living space. Then, while you're watching your mom run around collecting a strange assortment of food and clothing, but no pictures or mementos, the firewood you store under the A-frame (because- no eaves, right?) will catch fire about when you find out the fire department can't get their truck up the road.

I think a metal roof is a great choice for A-frames. Get something well galvanized and it will be a long time before anyone else has to do what you're doing. Make sure stove pipes are routed out fairly low where they can be inspected and repaired. Shingles are harder to flash, harder to replace, and will need to be replaced more frequently with that method of installation.

[Tradecraft]

Re: A Frame Insulation

No sir, no framing in the assembly. What I listed is all that is there. Thanks for the info. I presume the semi rigid was not the best choice for insulation?

[Riversong]

Re: A Frame Insulation

My website has Google Analytics code on it, which lets me look at who visits, where they come from (in some cases they come from here) and what they look at.

Jeezum Crow, everyone's a spie these days.