foam under the roof?

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Re: foam under the roof?

Postby schuimpge » Wed Mar 20, 2013 8:06 pm

John wrote:If a tiled roof sprayed with foam develops a leak it may go unnoticed for many years.

Trapped water can damage steel very quickly, more so when it gets diverted to the inside of hollow roof structures.

Its is extremely difficult to locate leaks on a tiled roof sprayed with foam.

This information is from years of experience in the construction industry not from a quick search on Google.

If a product has not become a standard, consider it carefully.


John, PU foam, when setting, develops individual cells that do not transfer water between them.
That's why they promote it to be water proof.
And I have difficulties figuring out how a tiled roof could develop leaks if properly laid.
Even more so if you have a PU foam layer under it that lasts 20 years or more.
Well, 20 years is a bit short, research shows 3 to 4 times that time before there's noticeable downgrading of the foam.

My experience is not in construction, it's in having a PU foamed roof in a 17 year old town house that did have leaks due to design problems when i bought it,...and previous lack of maintenance, and is now rock solid waterproof for 4 years.
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Re: foam under the roof?

Postby hansened » Sun Mar 31, 2013 8:08 pm

roberterik wrote:Dear members,
Does anybody has experience with the foam spraying under the roof for waterproofing/insulation?
Curious to get some info: how durable, what are the negative aspects, what are reliable companies?
I have a ceramic tile roof and every heavy rain I have some small leakage, and so far we could not find the location.
I have alufoil under the tiles, which makes location leakage difficult.



yes same probelm with a hole in the tiles. have to find small person to get in there with silicone. The spray foam leaves water all over. ,c ollects, and will all fall down when it finally lets down making a bigger problem. hard to find lprobelm where its leaking with the foam insulation.

NOw where to find a Lek lek person to get in the attic and walk on the std. poor Thai support system. 8)
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Re: foam under the roof?

Postby BKKBILL » Sun Oct 27, 2013 10:31 pm

Spray foam insulation can make some homes unlivable

Touted as green option, spray foam insulation can lead to off-gassing and health problems


http://www.cbc.ca/news/spray-foam-insul ... -1.2224287
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Re: foam under the roof?

Postby schuimpge » Mon Oct 28, 2013 6:33 am

Very bad journalism. One sided, read the comments...they shooting it down..typical hit-piece.
Spraying under your floor is not a good idea, never...it's your roof that benefits from it.
Walls? Nope...cavity fiber-glass or rock wool is the way to go..
Floor? Heating the floor and/or floor heating in cold climates. Good under-carpets also work well.
And Eco/Green spray foam? Come on...it's a chemical..adding more soy-sauce? :lol:
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Re: foam under the roof?

Postby Roger Ramjet » Mon Oct 28, 2013 1:00 pm

schuimpge wrote:Very bad journalism. One sided, read the comments...they shooting it down..typical hit-piece.
Spraying under your floor is not a good idea, never...it's your roof that benefits from it.
And Eco/Green spray foam? Come on...it's a chemical..adding more soy-sauce?
Luc

I agree, close to libel in parts, but not quite. The one comment I took notice of was Skuts from Holmes on Homes. If ever there was a reliable source that would be it.
Next they'll be printing: Mary Brown of Shitsville said that last week she ate a banana that gave her gas. We investigated and found that some bananas will give you gas. Don't eat bananas they are poisonous.
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Re: foam under the roof?

Postby Sometimewoodworker » Mon Oct 28, 2013 2:16 pm

schuimpge wrote:Walls? Nope...cavity fiber-glass or rock wool is the way to go..

Luc

The correctness of that answer really depends on the wall construction. With typical Thai building of cavity walls you are correct, but if you have a stud wall then closed cell foam is a better choice. It's faster to install and has a higher insulation value than your choices.

See "this old house" "the Bedford house" on YouTube for an example of where it is a better option.
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Re: foam under the roof?

Postby Makmak456 » Mon Oct 28, 2013 3:24 pm

I will be having my new steel roof done in a week or, and will post temp readings when completed.
I will add pics to my build story, too.
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Re: foam under the roof?

Postby schuimpge » Mon Oct 28, 2013 3:35 pm

Sometimewoodworker wrote:
schuimpge wrote:Walls? Nope...cavity fiber-glass or rock wool is the way to go..

Luc

The correctness of that answer really depends on the wall construction. With typical Thai building of cavity walls you are correct, but if you have a stud wall then closed cell foam is a better choice. It's faster to install and has a higher insulation value than your choices.

See "this old house" "the Bedford house" on YouTube for an example of where it is a better option.


I checked out some parts of it...nice series, gotta see more of that.
But, for the "Bedford House", in Episode 7 they are isolating the cavity walls.
That's fibre/glass or rock wool as far as I can see. They got a small cutter/crusher cutting up larger chunks and that's blown into the cavity-wall. (unless those chunks are closed cell foam blocks...
Only checked the visuals, need to go back to that later with audio.

cheers,
Luc
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Re: foam under the roof?

Postby Sometimewoodworker » Mon Oct 28, 2013 7:15 pm

schuimpge wrote:
Sometimewoodworker wrote:
schuimpge wrote:Walls? Nope...cavity fiber-glass or rock wool is the way to go..

Luc

The correctness of that answer really depends on the wall construction. With typical Thai building of cavity walls you are correct, but if you have a stud wall then closed cell foam is a better choice. It's faster to install and has a higher insulation value than your choices.

See "this old house" "the Bedford house" on YouTube for an example of where it is a better option.


I checked out some parts of it...nice series, gotta see more of that.
But, for the "Bedford House", in Episode 7 they are isolating the cavity walls.
That's fibre/glass or rock wool as far as I can see. They got a small cutter/crusher cutting up larger chunks and that's blown into the cavity-wall. (unless those chunks are closed cell foam blocks...
Only checked the visuals, need to go back to that later with audio.

cheers,
Luc


That is cellulose, you want episode 12 about 20 mins that is where they are doing the new build with spray foam
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Re: foam under the roof?

Postby Mike Judd » Tue Oct 29, 2013 5:25 am

Most steel roofs now days in Oz have the double sided Foil insulation with Fibre glass or rock wool in between laid ON the battens so that the steel profile is pressed against it , thus insulating and reducing rain noise. I think I prefer that to spraying , but maybe it's cheaper.?
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Re: foam under the roof?

Postby Mike Judd » Tue Oct 29, 2013 5:39 am

Here's a photo of my roof in Sydney, replacing tile profile metal sheets. Old insulation under them was left in.
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Re: foam under the roof?

Postby Sometimewoodworker » Tue Oct 29, 2013 5:55 am

Mike Judd wrote:Most steel roofs now days in Oz have the double sided Foil insulation with Fibre glass or rock wool in between laid ON the battens so that the steel profile is pressed against it , thus insulating and reducing rain noise. I think I prefer that to spraying , but maybe it's cheaper.?

I would think that the Oz system would be cheaper and faster but with a bit less insulation. It also looks as if there is wood used and the roof is sheathed before the insulation and metal is put on. That system isn't common practice here.
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Re: foam under the roof?

Postby schuimpge » Tue Oct 29, 2013 8:31 am

Mike Judd wrote:Most steel roofs now days in Oz have the double sided Foil insulation with Fibre glass or rock wool in between laid ON the battens so that the steel profile is pressed against it , thus insulating and reducing rain noise. I think I prefer that to spraying , but maybe it's cheaper.?


Your system is definitely cheaper and when laying a complete new roof (or replacing the tiles/sheets), it's easy to do it that way.
Holland, mostly tiled roof, with wooden trusses. first a layer of wood is put on top, then the battens, then the tiles..
Isolation is put under the battens if it's a new build. With retro-fit isolation, Isolation is done from the inside, under the wood, between the trusses.
The wood cover is also a prevention against storm/wind gusts that could easily lift the roof off, as it could easily get under the tiles if no wooden layer is present.
Especially old farms have this problem, as it is only the wooden trusses and battens with the tiles directly on top.
Term in Holland for such roof is "onbeschoten kap", which means as much as Non-Covered Roof.
Picture below of such old roof:
DownloadedFile.jpg
DownloadedFile.jpg (12.17 KiB) Viewed 931 times


For a retro-fit insulation, especially the way houses are build over here in Thailand, (for example the concrete-filled ridge-caps and edges), foam would be a very good option.
So far, I have no problems at all with my spray-foam. That's about 5 years in now. It's certainly brought down the noise and heat.
Still need to fit a glass tower with fan on top for some ventilation as it works two ways of course with mornings being much cooler outside.
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Re: foam under the roof?

Postby Mike Judd » Thu Oct 31, 2013 5:51 am

I wasn't too clear with my post, my house was an old house that I decided for many reasons to renovate instead of knocking it down and building new. That's why you see the old insulation under the new, there was no reason to remove it as the battens were good. With completely new roofs the battens (steel or wood) are placed down first, then the insulation of what ever thickness and price you go for, (the most expensive is quite thick with more air cells) then the sheeting is placed on top. Having the insulation touching the sheets deadens the noise effectively .
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Re: foam under the roof?

Postby geordie » Fri Nov 01, 2013 10:56 am

If I ever have time ??? I will document the current build but the guy had a financial crisis (no vehichles imported could be registered}
however back to topic unable to locate suppliers around Ram Intra the roof metal came from Bang Na with foam already glued to it
as far as heat and noise were concerned I thought it worked very well at preventing both
The owner decided he would like fiberglass wool also ?? we installed the 4" thick wool using chicken wire tied between the steel joist the roof is sitting on as I do not like to trap heat in rooms with insulation
The noise level before the fiberglass was applied was minimal but having added the fglass its totally unreal from both a noise and heat point of view with cavity walls upvc windows and as yet no ceilings its quite dramatic the ambient noise level increase by simply opening a window as yet we still have no ceilings so a further reduction is expected
I have a D B meter some where so will give comparisons later but the argument that foam will mislead you on roof leaks is a non starter so will foil and also fiberglass when foil backed the water will track across to the lowest point
I can vouch for this because one of my idiots decided to add screws where no joist were present
Metal roofs have a second benefit foam or no foam walk on the joists the valley of the metal sheets should be sitting solid on the steel
I am no lightweight but have walked across the roof several times
The same thing of course is true of tiled roofs by walking on the area of overlap (bottom edge of tile)
if laid properly you should find it will support your weight
my comments may be wrong but never deliberately
If it aint broke, dont fix it
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