Tapered radius extruded polystyrene insulation


#1

Does anyone make a tapered radius insulating foam board?
Looking for some bright ideas :idea: to get a tapered radius - Any takers?


#2

if im understanding you correctly, you want to taper in circles? i believe you need to figure your low point and put four rectangular pieces in the middle. then, stick a nail attached to a string in the center of the low point, with another nail on the string on the furthest point of the insulation, then use the second nail like a compass and draw a perfect circle. keep using the string and taper as usual… if i understand you right. there might be a special order cad and cam system, but you can do it yourself if you want to get that complicated.


#3

p.s. you need to “graduate” the insulation to do this concave and a perfect circle on second thought, and youll need software just to know how many pieces to start with at what angle to get to the middle of drains if its a large span.


#4

jm.com/roofing_systems/built … o_foam.pdf

Im looking for somthing like this - kind of like they use for crickets or for water channeling on flat roofs - but I want it to be a radius as opposed to a straight line like in that pic above - from the thicker part to the thinner part - does anyone know if that is available?

Ive looked through GAF, Dow, JM etc and not found what Im looking for.


#5

well… what I said earlier. you have to make it from those square boards. lots of waste. lots of planning. lots of work… and a simple string. I wish I was more technical on a computer or my scanner was working and I could upload a drawing. its not really too difficult mentally, its just more work than its worth. You want to end up with… a bunch of bowls with drains in the middle, right? Its super expensive as theres a ton of waste and its a ton of work manually. I know of no product thats made this way. I could learn something new too.


#6

I have considered doing it myself as it is a small project - Ive figured out that using a stainless steel wire and a battery charger make quite a nice material shaper. However Im not sure if I want to experiment too much on that venue - Ill let you know we are going to do some trial runs tonight with the set up wish me luck - hope I dont get electricuted or burn the place down. This might be the way to go if the shaping or “cutting” works out well.

Area is only 30X9 - so the shaping is really minor. Waste is not a concern since thats what I do now!!

We are adding pitch to of all things an RV - motorhome roof. Original was flat aluminum roof that failed.

Were going to repair the damaged area and add the foam to the top of the roof - sarnafil on top - should be quite trick once completed.


#7

[quote=“consolidatedwm”]I have considered doing it myself as it is a small project - Ive figured out that using a stainless steel wire and a battery charger make quite a nice material shaper. However Im not sure if I want to experiment too much on that venue - Ill let you know we are going to do some trial runs tonight with the set up wish me luck - hope I dont get electricuted or burn the place down. This might be the way to go if the shaping or “cutting” works out well.

Area is only 30X9 - so the shaping is really minor. Waste is not a concern since thats what I do now!!

We are adding pitch to of all things an RV - motorhome roof. Original was flat aluminum roof that failed.

Were going to repair the damaged area and add the foam to the top of the roof - sarnafil on top - should be quite trick once completed.[/quote]

Are you a roofer or a DIY’er? You know that most companies that do Sarnafil will not even let a veteran roofer do anything but labor on these roofs if the roofer hasn’t been factory trained, right? Sarnafil is THE best flat roof in my area, IMO. But, the heat welding on the seams is more of an art form than one might think. Aside from the fact that an overheated seam negotiates the integrity of the material and underheating the seams results in leaks… just trying to keep the heat gun moving at a steady consistent correct speed while simultaneously rolling the seam with the roller and not missing any spots feels as awkward at first as trying to pat your head and rub your belly while jumping on one foot at first. It takes some practice. I learned in the shop after hours many many nights playing with scraps, and thirty year roofers were telling me what I was doing wrong and right (laughing at me often). Then they did let me on the roof when my welds were nice and consistent and I proved it. If your roof doesn’t leak and you have no experience then you got lucky… even then… wait a couple of years. I made the assumption that youre not a roofer if you can’t even taper a roof on your own. I’m not trying to bash you. I’m trying to save you a huge headache.


#8

I agree with what S&G said, but I have one thing to add.

I assume you are talking about using expanded polystyrene since you are trying to taper it with a wire and battery charger. If this is true, you will not be able to adhere the roofing membrane to the insulation. Next, you are talking about installing the Sarnafil on an RV. Do you realize what is going to happen to the roofing membrane when you get going down the road at high speeds? My guess is you won’t keep the new roof on your RV very long! :frowning:

Why is it you are trying to use Sarnafil for this project? Is it something that someone gave you?

Once again, I’ll give you the same advice I give most people. Post a photograph so we can see what it is that you are trying to do.


#9

[quote=“Cerberus”]I agree with what S&G said, but I have one thing to add.

I assume you are talking about using expanded polystyrene since you are trying to taper it with a wire and battery charger. If this is true, you will not be able to adhere the roofing membrane to the insulation. Next, you are talking about installing the Sarnafil on an RV. Do you realize what is going to happen to the roofing membrane when you get going down the road at high speeds? My guess is you won’t keep the new roof on your RV very long! :frowning:

Why is it you are trying to use Sarnafil for this project? Is it something that someone gave you?

Once again, I’ll give you the same advice I give most people. Post a photograph so we can see what it is that you are trying to do.[/quote]

S&G and Cerberus - You are both on the money.
As far as the material goes it was left on a jobsite as leftover material - roofing company did not want to send someone to pick it up so we were able to score it - Ive been told it is wide enough so that there will be no seams on this job, and that is what I want. Even though I love to weld I have been told numerous times that we will need someone in the know to do the welding should any be needed.
Now, stopped at one of the local roofing supply houses today and was told exactly what both of you have referred to - the polystyrene is out and a fiberglass covered insulation that is tapered is now in. We have decided mechanical attachments on both long sides of the unit and at the front and back of the unit to boot. I have been assured that this is a good roofing material but one of the guys wondered about the moving of the vehicle and if that would affect the material - My feeling is that a fit that is not too tight is in order and will keep that in mind on my install.
On what I am - well I am a DIY but was in the roofing trade for a large commercial roofer for a while and know enough to be dangerous. Laboror only with no real skills to speak of roof wise - I was young but it did teach me some good life lessons.
Im keeping pics of the project and willpost them as things progress - project needs to be completed by end of October so its going to be an all hands on deck weekend warrior (with a full time roofer as our leader) event to say the least.
Any further suggestions are appreciated!
Im not sure yet but someone mentioned Eternabond as a product for going over front seam - where roofing meets fiberglass - and in back where roofing meets aluminum, Anyone used that stuff before?


#10

just when you think you’ve heard it all


#11

I’m skeptical to say the least. If you don’t fully adhere your Sarnafil to a sound and secure substrate, you can almost count on the roof membrane being sucked off your RV.

Photos? ? ? ? I’d like to see what it is you have to work with, so I can either give you advice or laugh at you! :mrgreen:


#12

Now wouldnt a nice spray-applied, self flashing, seamless, tenaciuosly bonded waterproofing liner be nice on this application?


#13

You’re killing me Aaron! :mrgreen:


#14

OK - so my roof is going to be sucked off going down the highway - the guy thats been in the bus for 36 years is rolling of the damn floor and Aaron is pushing a modified bed liner to put on my roof - damn - now im more confused than ever.
Just how does it get sucked off if it is completely secured with mechanical attachments at all four sides as well as having some items like vents that protrude through the roof Vents are generally placed over the membrane when using rubber with butyl tape between the two - coated with material after and maybe even eternabond .

Is a good general view of what were dealing with.

Aaron - how much per square foot and where can I see it online used for roofs?

That is actually being done by one of the manufacturers - 07 is the first model year it is done with.


#15

Now you’re giving me more credit than I deserve. I’ve only been involved in the roofing industry for 26 years.


#16

$10 bucks says it doesnt last ten miles


#17

Modified bedliner? Bedliner is a modified polyurea.

Roofboss, you talking about the polyurea?


#18

Heh heh heh - - - that was for roofboss


#19

So are you saying that using a .048 mil sarnafil for this project is not making any sense to you or are you saying that the insulation is not going to work?

Id like to get some more constructive critisism as opposed to wise cracks from guys that have spent too much time in the sun, any odds of that Roofboss? Ill bet 10 bucks there is not a chance. Your too busy knowing what you know and not willing to share that info in a manner that one can understand, anyone to succeed and your way of conveying that is to let little pieces of good info out among your feeble attempts at insults - not that I cant take it cause I can - raised by a WWII marine.

Oh well - if there is any more constructive info you all could give me I would appreciate it for sure.

Can also help you next time you need a dumpster : o ) even you ol boss of roof.


#20

[quote=“AaronB.”]Modified bedliner? Bedliner is a modified polyurea.

Roofboss, you talking about the polyurea?[/quote]

Aaron, Do you feel that might be a real alternative?