New roof advice

[Sheryl]

Not easily, no. The easy tearing occurs at the edge where the roll starts.

There are also spots where the aluminum has come off and the brown paper is visible on the side that should be reflective (with the one ply there is no doubt which side is reflective since the aluminum is on one side only..) so the aluminum deems quite thin.

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[Sheryl]

3 minutes ago, simoh1490 said:

From what I've read this evening, nearly all RB's have a kraft layer and a foil layer, it's the foil layer that must face the attic floor. All of them having a kraft paper coating is consistent with what we know about the two RB products we've seen, the one I have and the one you've just purchased. When I said I burnt mine over a stove and one side burned, what burned was the kraft paper albeit it didn't look like paper.

 

Sooo, it sounds like they have changed the manufacturing process and the appearance of the product. On that basis, you have purchased RB so I recommend you use it.

 Well that feels better than thinking I have wasted all this money and have no idea where to get the right thing.

 

But I remain concerned that the product seems so flimsy.

 

If the foil layer faces the attic then the brown paper faces the roof? That really seems counterintuitive, how can that work? As I understand it this works because the foil does not absorb heat so sends it reflecting backward to the roof. Will the heat pass through this brown paper to the foil?

[simoh1490]

2 minutes ago, Sheryl said:

Not easily, no. The easy tearing occurs at the edge where the roll starts.

There are also spots where the aluminum has come off and the brown paper is visible on the side that should be reflective (with the one ply there is no doubt which side is reflective since the aluminum is on one side only..) so the aluminum deems quite thin.

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That first line is good.

 

The second line is a problem and sounds like a quality issue, I'm becoming more convinced we've both got the same product but the product has been redesigned since I bought mine.

 

Two choices: go with what you've got or try to find something more robust. I know Home Mart stores have a very good roofing material display set up in most of their stores and the RB they use is super heavy duty, I was looking at it and touching this afternoon, I have no idea of cost.

 

Sorry, but you're going to have to call this based on what you see in  the product you have - if the flaws are minor you may choose to go with it and hope it doesn't deteriorate further installation. If you go for a replacement with a superior product it's a question of time and cost. Sorry again that I can't help further on this aspect.

[Sheryl]

From this how-to, indeed it is as you guessed Simoh

 

http://www.instructables.com/id/DIY-Attic-Radiant-Barrier/

 

But thiso ne says the foil should face the roof. ??

 

[Kwasaki]

30 minutes ago, simoh1490 said:

I don't understand what you wrote here or why.

Why because you have your own beliefs in what is best used in re-roof construction or new roof construction l didn't spend 15 years in getting qualifications for fun l got my qualifications because l know what is best to do in any new roof build or re-refurbishment roof re-roof design etc etc.

Architects use to employ me for roof advice and l spoke at European roof seminars.

l dislike showing my credentials that's why l put it in thaivisa profile. 

[simoh1490]

3 minutes ago, Sheryl said:

 Well that feels better than thinking I have wasted all this money and have no idea where to get the right thing.

 

But I remain concerned that the product seems so flimsy.

 

If the foil layer faces the attic then the brown paper faces the roof? That really seems counterintuitive, how can that work? As I understand it this works because the foil does not absorb heat so sends it reflecting backward to the roof. Will the heat pass through this brown paper to the foil?

Remember this: "Radiant barrier works via emissivity which is the opposite of reflectance . The barrier gets very hot but because the shiny surface emits very little heat (i.e. it has low emittance) and because the shiny surface faces inwards it radiates very little heat into your attic space. It's a radiant barrier. Not a reflective barrier".

[simoh1490]

1 minute ago, Kwasaki said:

Why because you have your own beliefs in what is best used in re-roof construction or new roof construction l didn't spend 15 years in getting qualifications for fun l got my qualifications because l know what is best to do in any new roof build or re-refurbishment roof re-roof design etc etc.

Architects use to employ me for roof advice and l spoke at European roof seminars.

l dislike showing my credentials that's why l put it in thaivisa profile. 

For gods sake kwasaki I'm not arguing with you or disputing anything you say! And currently, the major problem is Radiant Barrier which if you can help with would be great.

[grollies]

I'm glad I'm not building a roof, I left that to my wife. Sounds very complicated.

[simoh1490]

11 minutes ago, Sheryl said:

From this how-to, indeed it is as you guessed Simoh

 

http://www.instructables.com/id/DIY-Attic-Radiant-Barrier/

 

But thiso ne says the foil should face the roof. ??

 

I think simply he's wrong, although from a physics standpoint it may not matter a huge amount whether the paper is on one side or the other of the foil. Certainly, one is going to be more effective than the other but by how much is very unclear to me but I think it's not going to be very much - I did read recently that the difference was 3% but there was no explanation of why or how that number arrived at.. That article dated 2008 also, maybe thinking has moved on but I think he's simply got it wrong.

[Sheryl]

Indeed it is. And me with zero knowledge of such things. Very stressful.

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[Sheryl]

Remember this: "Radiant barrier works via emissivity which is the opposite of reflectance . The barrier gets very hot but because the shiny surface emits very little heat (i.e. it has low emittance) and because the shiny surface faces inwards it radiates very little heat into your attic space. It's a radiant barrier. Not a reflective barrier".

Ok. And except for the one site I posted above everywhere I am reading says the foil should face the attic.

I will go ahead and install what I have in the worker's house first and depending on how that goes may then return the unopened rolls and search for stronger material or not.

Many thanks for your help Simoh!

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[simoh1490]

Just now, Sheryl said:

Ok. And except for the one site I posted above everywhere I am reading says the foil should face the attic.

I will go ahead and install what I have in the worker's house first and depending on how that goes may then return the unopened rolls and search for stronger material or not.

Many thanks for your help Simoh!

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You're most welcome. I'll go see Home Mart tomorrow and find out what they have and how much and get back in touch. In the meantime, relax, it's all going to work out just fine. I'm signing off for the night.

[carlyai]

Sheryl, is there a www address on the foil roll?

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[Sheryl]

No. The NASH brand had a call center number which I used to verify which side should face where. The Sunshield has nothing and I have been unable to find a website for them.

I think we have established that what I have is an RB just seems to be not great quality.

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[carlyai]

I think the brown paper is a safety modification. Lots of people started getting electrocuted with foil insulation. I think the shiny foil side goes out and the safe paper side goes in...my theory.

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[Sheryl]

According to all websites the shiny side faces in so the paper side (or, in case of 2 ply the smoother aluminum side) faces the roof.

Actually some say it will work either way but if the shiny side faces the roof over time as it picks up dust etc it may become less effective.

People can get electrocuted by a RB?? First time I have heard that. So we need to turn off electricity while it is installed? Will be difficult as it has to be affixed to metal purlins...

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[wayned]

5 hours ago, Sheryl said:

People can get electrocuted by a RB??

I found this article and it basically answers your questions  about the paper and electrocution;

 

"Radiant barriers consist of a highly reflective material, usually aluminum foil, which is applied to one or both sides of a number of substrate materials such as kraft paper, plastic films, cardboard, oriented strand board, and some products are fiber-reinforced to increase durability and ease of handling.

 

Installation

A radiant barrier's effectiveness depends on proper installation.  In a new house, an installer typically drapes a rolled-foil radiant barrier foil-face down between the roof rafters to minimize dust accumulation on the reflective faces (double-faced radiant barriers are available).

When installing a foil-type barrier, it's important to allow the material to "droop" between the attachment points to make at least a 1.0 inch (2.5 cm) air space between it and the bottom of the roof.

Note that reflective foil will conduct electricity, so workers and homeowners must avoid making contact with bare electrical wiring."

[simoh1490]

But since the wires in Sheryl's roof are already in yellow conduit and joint boxes, there should be minimal risk. Remember this is Thailand and lots of older houses still have bare wires running through the attic, that has to be the segment of the market the manufacturing change of the RB was targeted at and that's where the risk of electrocution is the greatest. 

[wayned]

1 hour ago, simoh1490 said:

minimal risk

Would you be willing to take the risk.  All of the wires in Sheryl's house could be double or tripped insulated and well protected, but have you inspected the cords and extensions that the crew will be supplying to actually do the work and I'm not sure how you get around that problem unless you personally inspect the tools or supply them yourself. 

 

 

[carlyai]

You would have to install the RB the way the manufacturer says, but from the video about installation, it shows the foil towards the roof.
Also, you have gone for white roofing to help stop heat getting into the house by absorption, reflection, what ever way it does it, but you want to put a dull, non reflective, heat absorbent surface next to the roof metal.

You wouldn't have installed a brown roof.

I think dust is mainly a factor if the foil is lying on the ceiling. You've got all those trees around to catch the dust.

At the end of the day a shiny surface reflects and a dull surface absorbs. (This could have changed since I went to school). [emoji3]

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[carlyai]

From the way I read some research articles on RB, the reflective layer must point towards an air space So if you have a 2" gap between the metal roof and the RB, this is an air space. Same can be said about the inside of the attic, that is an air space. So it may not matter which way it is installed.

So this then brings into

play the next important question: which side is the most waterproof? If the foil is the most waterproof, then it points towards the roof; if the brown paper is the most waterproof then it points towards the roof.

Electrical safety is still a big issue.

 

I suppose you have looked at the other option of insulating above the hanging ceiling? Everything considered, this maybe a far easier option...sorry.

 

The company I bought my RB from shows a video of installing their stuff in the hanging ceiling.

It's all in Thai, but it's the first installation video on the RHS.

 

www.m-pe.com

 

 

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[Kwasaki]

11 hours ago, simoh1490 said:

For gods sake kwasaki I'm not arguing with you or disputing anything you say! And currently, the major problem is Radiant Barrier which if you can help with would be great.

OK l'll help,  Sheryl should find a Global House there many types of roofing underlay all suitable for the roof build.

[Kwasaki]

2 hours ago, wayned said:

Would you be willing to take the risk.  All of the wires in Sheryl's house could be double or tripped insulated and well protected, but have you inspected the cords and extensions that the crew will be supplying to actually do the work and I'm not sure how you get around that problem unless you personally inspect the tools or supply them yourself. 

Lets hope Sheryl got a safe 'T' cut installed in the house electrics. 

[Kwasaki]

16 hours ago, Sheryl said:

The purlins are 3 x 2 so I think commercially bought spacer should work?

I would confirm and check that because as the lads here have posted a top hat section spacer needs fixing at alternate sides at a measured distance.

 

If the stock top hat spacers are too wide as said before you can use a stocked zed spacer that will perform the task just as well.

 

16 hours ago, Sheryl said:

I was under the impression that the spacer alone would provide sufficient spacing and we'd just use short screws to affix the spacers to the purlins (screws passing thru the RB). Is that not the case?

 

Yes as shown in a previous post sketch.

[Sheryl]

A little late to be debating the pros and cons of RBs now, guys! I have already decided - -after reviewing tons of literature -- to put one in and already bought it.

 

It definitely does go with the reflective side facing into the attic. This puzzled me at first too, and has puzzled many others and there is lots on this online. Basically the answer is that a radiant barrier does not work by reflecting heat but rather by not radiating it. Basically the heat gets as far as the RB and then has difficulty getting any further because the RB does nto radiate heat well. "Reasons to have it pointing down are that if it were pointing up, part of the reflective surface will be touching the roof or roof trusses, allowing conductive heat transfer, reducing its effectiveness. that's probably the main reason, but also, dust will tend to land on the top surface, and if that were the reflective side, that would also reduce its effectiveness."  http://boards.straightdope.com/sdmb/showthread.php?t=645008

That interesting explanation suggest to me that the 2 sided ones may not be a good idea since there will then still be some conductive heat transfer...???

 

Reflective effect is hoped to come from the use of white roofing. (Though my current roof is a natural grey so nto sure how much difference there will be from that to white?).

 

Thanks for the heads up re electrical risks during installation. Since it is not going on the floor it will not be in contact with any wires but the risks will be the sparks from electric drill etc and frankly I don't know what to do about that...and unfortunately no, I do not have a safety cut etc, want one and have had trouble getting it and once the roof is done and I have recovered from it (which may take a while ) I will resurrect and restart one of my several old threads on my electrical issues. Unfortunately while iI know good roofers and all-purpose handymen in Cambodia I do not know any good electricians (not sure there are any to be found in the country truth be told, and if there are they are in highly paid jobs with international companies in the capital), I could write a horror novel of what the local "electricians" have done in my house (including actual electrical fires) and I have never been able to interest any electricians elsewhere in coming out here.

 

But let's table that issue please for now, and concentrate on what can be done to ensure worker safety during RB installation, if anything. They will be wearing rubber soled sneakers, I already bought a pair for each of them (didn't want them falling off the roof!).  Would rubber gloves while drilling help? any other simple measures I can take? I can turn off the electricity in the house but then they would still need to power their tools (we can run an extension cord if need be from worker's house next door) so not sure that it helps anything, unless there is some sort of device that can be used on the tools or their extension cord. Even then, there will still be sparks and some will land on the RB. ???

 

In terms of risks once installed I would think insulation batts, which are wrapped in aluminum foil, would be the greater risk since it sits on the ceiling where are the wires are, ceiling fans are attached etc. I have been a little uneasy on that point all along but if using Colorboind need the noise insulation. Which leads me to the next item/news:

 

The Colorbond supplier has still, despite multiple phone calls, not gotten back to me with specs and at this point unless I receive them within the next few hours, and provided I can source the fibre cement tiles I would want (TPI Cool series in white, the only white tiles that seem to exist here) I am giving up in despair at sourcing Colorbond  and using tiles as originally planned.

 

In THAT case, I will not put in insulation batts, only the RB and of course the vented eaves boards, and hopefully these plus the white color will make things at least a little cooler than they were.

 

I would also in that case not dare use a TH spacer because of the weight of the tiles so the RB will have to be installed inside the raters. We will have a trial run of that in the worker's attic first.  The crew has some ideas of how they want to try to do it to get around the problem of all the ceiling wires etc, I do nto fully understand their planned approach (involves somehow first attaching the sort of soft metal frames used for a hanging ceiling onto the rafters and then attaching the RB to it) but I am confident they understand what has to happen so let's see how they make out with it.

 

No real impact ion the valley gutter design issue whichever roofing material I use, I think? I am going to go up into the attic beneath it to see if it is possible from there to get a handle on how far up the sides of the existing one go.

 

Stay tuned....

 

 

 

"

[grollies]

I bought my builders safety harnesses to wear whilst constructing the pool roof.

[wayned]

8 minutes ago, grollies said:

I bought my builders safety harnesses to wear whilst constructing the pool roof.

Where did you buy the "sky hook"?

[grollies]

2 minutes ago, wayned said:

Where did you buy the "sky hook"?

5555

[carlyai]

A little late to be debating the pros and cons of RBs now, guys! I have already decided - -after reviewing tons of literature -- to put one in and already bought it.

 

It definitely does go with the reflective side facing into the attic. This puzzled me at first too, and has puzzled many others and there is lots on this online. Basically the answer is that a radiant barrier does not work by reflecting heat but rather by not radiating it. Basically the heat gets as far as the RB and then has difficulty getting any further because the RB does nto radiate heat well. "Reasons to have it pointing down are that if it were pointing up, part of the reflective surface will be touching the roof or roof trusses, allowing conductive heat transfer, reducing its effectiveness. that's probably the main reason, but also, dust will tend to land on the top surface, and if that were the reflective side, that would also reduce its effectiveness."  http://boards.straightdope.com/sdmb/showthread.php?t=645008

That interesting explanation suggest to me that the 2 sided ones may not be a good idea since there will then still be some conductive heat transfer...???

 

Reflective effect is hoped to come from the use of white roofing. (Though my current roof is a natural grey so nto sure how much difference there will be from that to white?).

 

Thanks for the heads up re electrical risks during installation. Since it is not going on the floor it will not be in contact with any wires but the risks will be the sparks from electric drill etc and frankly I don't know what to do about that...and unfortunately no, I do not have a safety cut etc, want one and have had trouble getting it and once the roof is done and I have recovered from it (which may take a while ) I will resurrect and restart one of my several old threads on my electrical issues. Unfortunately while iI know good roofers and all-purpose handymen in Cambodia I do not know any good electricians (not sure there are any to be found in the country truth be told, and if there are they are in highly paid jobs with international companies in the capital), I could write a horror novel of what the local "electricians" have done in my house (including actual electrical fires) and I have never been able to interest any electricians elsewhere in coming out here.

 

But let's table that issue please for now, and concentrate on what can be done to ensure worker safety during RB installation, if anything. They will be wearing rubber soled sneakers, I already bought a pair for each of them (didn't want them falling off the roof!).  Would rubber gloves while drilling help? any other simple measures I can take? I can turn off the electricity in the house but then they would still need to power their tools (we can run an extension cord if need be from worker's house next door) so not sure that it helps anything, unless there is some sort of device that can be used on the tools or their extension cord. Even then, there will still be sparks and some will land on the RB. ???

 

In terms of risks once installed I would think insulation batts, which are wrapped in aluminum foil, would be the greater risk since it sits on the ceiling where are the wires are, ceiling fans are attached etc. I have been a little uneasy on that point all along but if using Colorboind need the noise insulation. Which leads me to the next item/news:

 

The Colorbond supplier has still, despite multiple phone calls, not gotten back to me with specs and at this point unless I receive them within the next few hours, and provided I can source the fibre cement tiles I would want (TPI Cool series in white, the only white tiles that seem to exist here) I am giving up in despair at sourcing Colorbond  and using tiles as originally planned.

 

In THAT case, I will not put in insulation batts, only the RB and of course the vented eaves boards, and hopefully these plus the white color will make things at least a little cooler than they were.

 

I would also in that case not dare use a TH spacer because of the weight of the tiles so the RB will have to be installed inside the raters. We will have a trial run of that in the worker's attic first.  The crew has some ideas of how they want to try to do it to get around the problem of all the ceiling wires etc, I do nto fully understand their planned approach (involves somehow first attaching the sort of soft metal frames used for a hanging ceiling onto the rafters and then attaching the RB to it) but I am confident they understand what has to happen so let's see how they make out with it.

 

No real impact ion the valley gutter design issue whichever roofing material I use, I think? I am going to go up into the attic beneath it to see if it is possible from there to get a handle on how far up the sides of the existing one go.

 

Stay tuned....

 

 

 

"

Well done sheryl. That's the beauty of diy, at the end of the day, and with the help of a few friends the final decision rests with you.

 

I really wouldn't worry about the sparks from the metal saw/drill, too much, if the RB paperside, facing outward doesn't burn.

 

EDIT

 

I deleted this until I reread your last post.

Workers are pretty careful, but I would check those extension leads they use where they put the wires into the white extension lead sockets.

 

You could buy a couple of rechargable screw guns and charger.

 

These would definitely come in handy for putting in all the metal screws, and no extension leads. My guys used them to put in all the bird stop windows....helps.

 

 

 

 

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[Kwasaki]

3 hours ago, Sheryl said:

TPI Cool series in white, the only white tiles

Tiles ? ?