How important is Azdel?

[Cumminsfan]

Originally Posted by rloewenhagen

Look at the overall thickness of the walls... builders using Luan instead of AZDEL are usually the same builders who give you 1 1/2 inch thick walls instead of 2 inch thick walls. Coupled with AZDEL, 2 inch thick walls have 40% greater insulation "R" value than Luan on 1 1/2 inch wall thickness. In a motorhome or trailer, this makes a big difference in how you handle heating and cooling. ALSO, look for fiberglass roofing (single piece)... over the past 45 years, I've had every type of roof there is. I will never buy any coach that doesn't have a fiberglass roof today.

Not quite following your logic about Azdel vs Luan and 1.5" vs 2".
I have a Luan sided TT with 2" walls. I see Azdel and Luan used in either thickness as more of a cost factor and a 'Lite' vs 'Heavy build rather than the fact that because there's Luan or Azdel the walls always 1.5" or 2".
Depending on brand Azdel is not used in all four walls. It also offers hardly anymore R value. In fact the foam density in a Luan sided trailer could easily offset the R value from Azdel.

[bneukam]

Azdel has 3X the insulation value compared to Luan. But considering Luan has a .36 r-value we are not talking big numbers.

It’s the Rot, mold, and water resistance. Plus it’s temperature, and humidity change tolerance is what makes Azdel a more stable product over Luan. It’s also 50% less weight.

About 10 manufacturers are now using it, and for those that don’t, it boils down to cost.

But don’t forget to look at how the floor, and roof are constructed, and insulated. They are equally, or more important. Thick rigid foam board with layers of 1/4 inch board on each side gives superior strength and insulation when it comes to radiation, conduction, and convection.

Our TT has the new XTRM Ply PVC roof with DuPont Elvaloy. Will not chalk, and no black streaks. 2X the puncture strength over TPO. Plus it has 86% solar reflection, and 87% thermal emissivity. Have had all the other types of roofing materials, and this is the best I’ve seen thus far, but it’s only two years old.

[rloewenhagen]

Originally Posted by Cumminsfan

Not quite following your logic about Azdel vs Luan and 1.5" vs 2".
I have a Luan sided TT with 2" walls. I see Azdel and Luan used in either thickness as more of a cost factor and a 'Lite' vs 'Heavy build rather than the fact that because there's Luan or Azdel the walls always 1.5" or 2".
Depending on brand Azdel is not used in all four walls. It also offers hardly anymore R value. In fact the foam density in a Luan sided trailer could easily offset the R value from Azdel.

Better start reading the manufacturer's brochures and visiting the 'Build websites'... I did my homework and I stand by every word I SAID... I spent 9 months researching this issue.

[rloewenhagen]

Originally Posted by bneukam

Azdel has 3X the insulation value compared to Luan. But considering Luan has a .36 r-value we are not talking big numbers.

It’s the Rot, mold, and water resistance. Plus it’s temperature, and humidity change tolerance is what makes Azdel a more stable product over Luan. It’s also 50% less weight.

About 10 manufacturers are now using it, and for those that don’t, it boils down to cost.

But don’t forget to look at how the floor, and roof are constructed, and insulated. They are equally, or more important. Thick rigid foam board with layers of 1/4 inch board on each side gives superior strength and insulation when it comes to radiation, conduction, and convection.

Our TT has the new XTRM Ply PVC roof with DuPont Elvaloy. Will not chalk, and no black streaks. 2X the puncture strength over TPO. Plus it has 86% solar reflection, and 87% thermal emissivity. Have had all the other types of roofing materials, and this is the best I’ve seen thus far, but it’s only two years old.

I originally stated that many Luan builders (Thor the largest) use 1 1/2 thick walls as well as Luan rather than AZDEL... with AZDEL having 3X times the insulation value of Luan and another 1/2" of fiberglass insulation thickness, the insulation difference is seriously significant. Again, 40 + years of motorhoming has taught me two things to start with - AZDEL and Fiberglass roofs - both your A/C system and your roof maintainer will thank you.

[SJMaye]

Originally Posted by rloewenhagen

Again, 40 + years of motorhoming has taught me two things to start with - AZDEL and Fiberglass roofs -

Other than full fiberglass trailers, what manufacturers use fiberglass roofs?

[Sailorman295]

Fiberglass roofs are rare on rvs, I think mainly due to weight issues and expense. Initially TPO was designed to be a superior replacement for both PVC and EPDM rubber membranes. Also TPO and PVC are both thermoplastic materials. Both membranes are heat weldable and considered a green roofing material. Installation process is very similar. TPO has only been around for 20 years and has had some growing pains but is constantly being improved upon. PVC had it’s issues back in the eighties.

[SJMaye]

So, no reason to avoid TPO roofs?

[billyw]

No reason to avoid TPO roofs is a correct statement. Unless you specifically want a fiberglass or aluminum roof. Aside from black streaks, rubber roofs work perfectly fine too.

I'm also confused about the 1.5" versus 2" and azdel comparison. Azdel and luan are essentially the same thickness and the insulation factor is essentially non-existent.

[rloewenhagen]

Originally Posted by billyw

No reason to avoid TPO roofs is a correct statement. Unless you specifically want a fiberglass or aluminum roof. Aside from black streaks, rubber roofs work perfectly fine too.

I'm also confused about the 1.5" versus 2" and azdel comparison. Azdel and luan are essentially the same thickness and the insulation factor is essentially non-existent.

Again: read the factory brochures and published sales data... many motorhome manufacturers are using 1 1/2" wall thickness... they publish r-factors of 5 and 6 in their walls. The manufacturers using 2" thickness with AZDEL publish R-Factors 8 and 9+. That's a 25 - 30% difference in insulation. Also note the roof R-Value for each of these manufacturers. You will generally find that the manufacturers using AZDEL also went to the expense of using Fiberglass on the roofs... it may just be coincidental, but these manufacturers generally publish a 25 - 30% percent higher R-Value in the roofs. As for the TPO question: I spent 9 months crawling roofs at multiple RV dealerships throughout Arizona before I purchased a coach with AZDEL walls and a fiberglass roof... I couldn't find a single brand new coach sitting on a dealer's lot with a TPO roof that did NOT have wrinkles in it... that's called roof delamination (except for a couple of coaches that had just arrived from the factory)... after sitting on a dealer's lot for months on end in Arizona heat and sun, TPO roofs will delaminate.

[billyw]

I won't argue your specific points, but will point out on this "trailer forum" that fiberglass roofs can be had, but are fairly rare. You'll be fortunate to find your preferred floor plan under a fiberglass roof. I live in the northwest so can't speak to Arizona sun effects on TPO, except to say that I think it would still be functional even if some of the glue holding it down failed. If that's a real problem, there's many thousands of RVs in danger at this moment.

Azdel technically does have higher r value than luan, but neither achieves a value of even R1. The 2" thick walls have higher insulation value than 1.5" walls regardless of the presence of Azdel. I only argue this point to inform others that it's essentially a sales gimmick.

[bneukam]

Poly-iso is R-6, Extruded is 5.5, styrofoam is R-4 per inch.
Fiberglass batts is 3.5 per inch, but IMO has no use in RV’s. Cheap, and condensation will destroy it.

[Sailorman295]

Originally Posted by billyw

I won't argue your specific points, but will point out on this "trailer forum" that fiberglass roofs can be had, but are fairly rare. You'll be fortunate to find your preferred floor plan under a fiberglass roof. I live in the northwest so can't speak to Arizona sun effects on TPO, except to say that I think it would still be functional even if some of the glue holding it down failed. If that's a real problem, there's many thousands of RVs in danger at this moment.

Azdel technically does have higher r value than luan, but neither achieves a value of even R1. The 2" thick walls have higher insulation value than 1.5" walls regardless of the presence of Azdel. I only argue this point to inform others that it's essentially a sales gimmick.

I completely agree.

2019 Winnie Minnie Plus 26RBBS

[theoldwizard]

TPO comes in different thicknesses. 60 mil and above is considered "commercial".

[BubbaChris]

I have Azdel on my TT. I bought it used and it had a roof-to-cap joint leak thanks to a tree strike. I have some water damage to the front cabinets. No other issues related to leaks, but I've done a lot of my own sealing since then.

Here are my shopping tips:

1) Floorplan is the priority

2) Don't buy too much TT for your TV

3) If buying new, walk over to the service department (without a sales rep in tow) and ask what the warranty service process is like and how long it takes. I don't care how good the TT is if they tell you it will take a week for them to take a look, then 2-3 week wait for the parts to arrive, and then another week for the repair to get scheduled. I seriously got this version from a big local dealer who offers lifetime warranties.

4) If buying used, find a mobile RV tech who will come and fully inspect your potential TT (for a fee).

5) If you have a finalist decided, go read some on their owner-specific forums.

Best regards,
Chris