Masonite for roofing material?

[Sparksalot]

I have to agree with everything in this thread. However we used masonite on the entire Bluebonnet tear. The only thing I would have done different is what has already been voiced, I would have made sure it was well sealed from the weather before it was ever taken out of the garage.

After 4 1/2 years and over 16,000 miles the Bluebonnet is showing signs of wear. We are going to clean it up and epoxy it and I think it will keep it going for a long time to come.

Dave, I thought Bluebonnet might be masonite, but wasn't sure.

I'm glad I brought the topic up. I'm sure learning a bunch out of this discussion.

[Sparksalot]

I'd rather use good Masonite than cheap ply...you're gonna' seal the heck out of it anyway, we all do...

I have another 2Qt CPES kit ready just for the roof, hatch and doors. Yep, gonna seal the snot out of it.

[2bits]

OK how about Orange box Luan as a step up from masonite, but a step down from the $20 birch? Any objections? I was thinking of this myself since this step is coming up soon. I am planning to seal all joints with epoxy.

I've read elsewhere here really recently about 1/4" orange box luan cracking as it is bent around the radius.

I JUST finished putting the ceiling in. Feeling the tension in that forward portion made up my mind for me. I'm gonna do the birch.

Whew, yeah, I would bet the 1/4" would snap crackle pop, maybe you meant 1/8". I think the luan will bend fine as long as the grain is horizontal, not vertical. I plan to cover mine in .040 aluminum, so I still might do the luan, but those are very good points about voids and stuff, I would never consider luan for an exterior skin, if it is going to be exterior, get the good stuff for sure, but you did say "never to be seen again plywood" so obviously you decided on aluminum. Now... I am thinking $12 vs $20 hmm I could eat cheap a few times during the week and make that up and the tear would last alot longer. Time to mull this one over for a while too myself! haha

I guess if going cheap the choices are: Mush if masonite gets wet or cracks due to voids and knots in luan.

[bdosborn]

I used masonite on mine and its held up fine so far.



Of course I coated it with 4 coats of spar varnish and its underneath a filon skin. Has anyone tried a weather test on masonite lately? I found some 1/4" underneath a snowbank when we moved into our house that had been outside for at least 18 months and it was fine. Much better condition than plywood would have been. That being said, I'm not using it on build #2. It tends to tear around staples on bends and glue doesn't stick to it that well. I do think its an honest alternative to cheap plywood, provided you install it correctly.
Bruce

[satch]

.

Now... I am thinking $12 vs $20 hmm I could eat cheap a few times during the week and make that up and the tear would last alot longer. Time to mull this one over for a while too myself! haha

_________________
Thomas

You can do wonders with Top Romen!

[GPW]

We suspect the current Masonite might be better than the product used 50 years ago ...Progress...and no matter what we use , it all gets sealed like crazy anyway...

[GPW]

... and now the down side of the story... We used some pre-finished(white) Masonite panels for our ceiling on the inside... looked pretty slick until we sprang a leak and the water soaked the Masonite and stained the white surface...No chance of cleaning it up ,tried, now I have to replace that panel ...the leak was fixed long ago , but the stain persisted...

PS. had the Masonite been sealed on the other side ,this wouldn't have happened...but the white finish wasn't much of a sealer either...I'll be replacing it with some backprimed 1/8" ply...

[len19070]

I'm another one who uses Masonite.

For many reasons.

Once you bend any material around a rounded profile, It takes on entirely new dynamics. Much stronger than its origional thickness.

I have never built a trailer without a solid non pours material over the sheathing. Be it aluminum, filon, rubber etc. And will Never build one without a non-pours material over the sheathing.

Masonite can almost be tied into a knot.

Yes, its sawdust & glue...but its consistent sawdust and glue. I know I can bend it into almost any forum.

I have used plywood and cannot say that.

Masonite on an 1 1/2' roof lined both inside and out, glued and screwed, is a solid roof.

I have built many trailers..many styles of trailers for over 20 years.

No matter what you build with, if its not sealed properly...It will all turn to Oatmeal.

Attention should be turned towards sealing it.

Happy Trails

Len

[mikeschn]

Len,

Have you ever tried CPES?

And what do YOU typically seal it with?

Mike...

[len19070]

Len,

Have you ever tried CPES? And what do YOU typically seal it with?

Mike...

Mike

I've never used CPES to seal on a tear, but that stuff is great. For the most part I seal it with Spar Varnish that I coat the same time I varnish the base coats for the side walls on the Galley.

Now If I'm doing a rubber roof I don't do anything, just scuff it up and laminate right to it.

Same with Filon. (which I'm getting away from)

But under an aluminum roof I like the Spar varnish. If you add the aluminum with in a week or so of applying the varnish the aluminum will stick to it just enough to Keep it still while working on it. But then over time (usually by the first hot day) the aluminum will separate from the varnish and let the aluminum float.

The main reason I use Spar Varnish is I go through a lot of it for another operation in my business

Happy Trails

Len

[angib]

I'm reminded of how my former boss described the process of applying epoxy over plywood - "Think of it as varnish that you can apply six coats at a time".....

Andrew

[bgordon]

Len,

Have you ever tried CPES?

And what do YOU typically seal it with?

Mike...

Mike,

Now that you mention the CPES again. I have read in quite a number of threads about it, but we don't have that here (I don't think so anyway). What exactly is CPES? From your post I gather it is in sheet form, and something like masonite??

[GPW]

For waterproofing and sealing we use our old favorite ... 25% polyurethane, and 75% mineral Spirits... sinks in , waterproofs and is cheap ...Had I done that to my ceiling Masonite panels , I wouldn't have any problems ...

[mikeschn]

Clear penetrating epoxy sealer... I buy it here

http://www.rotdoctor.com/products/cpes.html

But over there, you might want to plan on sealing it with epoxy, or spar urethane like Len does.

Mike...

Len,

Have you ever tried CPES?

And what do YOU typically seal it with?

Mike...

Mike,

Now that you mention the CPES again. I have read in quite a number of threads about it, but we don't have that here (I don't think so anyway). What exactly is CPES? From your post I gather it is in sheet form, and something like masonite??

[2bits]

I keep reading that spar urethane will crack as the wood expands and contracts and epoxy is the way to go because it will dimensionally stabilize the wood. Are there two schools of thought on this? I am comfortable with spar urethane not to mention I have a $40 gallon of the stuff sitting on the shelf. I have already coated the walls and I am thinking toward the edges to keep moisture out.