secharles
New Member
Posts: 24
Likes: 1
Currently Offline
|
Post by secharles on Jun 17, 2024 1:45:35 GMT -8
Q: why do trailers not have exterior sheathing?
even if under the siding, it would offer strength & insulation.
my initial (years back) interest in classic design trailers came via the beauty of early
British caravans. to a point, maybe 1960?, they all seemed to be wood sheathed with
no additional covering except paint or brightwork.
i really believe 70% of the framing rot comes from condensation on the backside of metal siding
not leaks around penetrations.
|
|
John Palmer
Senior Member
![*](//storage.proboards.com/forum/images/stars/star_orange.png) ![*](//storage.proboards.com/forum/images/stars/star_orange.png)
Hi, From a vintage trailer guy located in Santa Ana, CA. It's good to see lots of activity here.
Posts: 1,706
Likes: 600
Currently Offline
|
Post by John Palmer on Jun 17, 2024 9:34:36 GMT -8
i really believe 70% of the framing rot comes from condensation on the backside of metal siding not leaks around penetrations. That cannot be overstated! We both agree on that point. I believe your 70% number is conservative. You have to figure out a way to stop, drastically reduce the warm, moist air from inside the trailer from working it's way to the inside of the cold aluminum skin where it condenses. John Palmer
|
|
|
Post by vikx on Jun 17, 2024 11:58:59 GMT -8
A lot of leaks in stick and tin trailers come from dried out putty at the top edge. Water leaks down insidiously, runs inside the wall and finally settles in the sills and sometimes the floor (metal bellies)
Sheathing the outside of the wall adds weight which the manufacturers didn't want. Many of our vintage trailers have lasted well for 50 years, so their methods weren't all bad.
The kind of trailer you're working on determines the rebuild method. Stick and tin trailers are repaired from the outside in, riveted body trailers are repaired from the inside out. I believe the riveted trailers have more condensation than stick and tin. JMO.
|
|
secharles
New Member
Posts: 24
Likes: 1
Currently Offline
|
Post by secharles on Jun 17, 2024 17:15:03 GMT -8
and following up - one question creates another - why don't vintage trailers at the rebuild stage use insulation?
and in this age, specifically 3M thinsulate batting?
if it's good enough for Sprinter conversions, what would the vintage trailer world lose by giving it a try?
even the poor man's version of synthetic batting sold at the local fabric store will
slow down air (= moisture) transmission. [edit] staple on some scrim to keep it in place. like the black stuff
covering the pad under your dining room chair.
for the thousands in parts, and sometimes 0 dollar value put on the hundreds of hours to rebuild a
vintage trailer, i think the additional cost in money & time of adding insulation would be well worth it.
|
|
|
Post by Teachndad on Jun 18, 2024 6:30:41 GMT -8
The vintage trailers were built with a thin layer of insulation. Cheap manufacturing processes had them sandwiching the insulation between the interior paneling and the wall framing. It was thin enough that it could be compressed. Here is a picture showing some insulation between the wood frame members in the wall. It was foil backed in some cases. The lower skin has been removed exposing the insulation to the right of the doorway. ![](http://i174.photobucket.com/albums/w117/Teachndad/Vintage%20trailers/1957%20Westerner%20-%20Andy/Front%20end%20and%20skirts%20lifted/P1070809_zps66e87559.jpg) Most people cut away the old insulation and insert batting insulation or even Styrofoam insulation that is meticulously cut to fit in between the wood framing. Skins have to be pulled first. Work from the outside inward. Here original insulation has been cut away with a razor knife. ![](http://i174.photobucket.com/albums/w117/Teachndad/Vintage%20trailers/1957%20Westerner%20-%20Andy/Misc%20progress%20photos/DSC004071_zpsvkquu348.jpg) In addition to restorers replacing the stock insulation, they also add a vapor barrier over the insulation. Search our vast archives for "vapor barrier" to learn more about it. Rod
|
|
|
Post by vikx on Jun 18, 2024 10:20:51 GMT -8
Almost all of my vintage trailers had insulation; some more than others. For the more robust built trailers, foam insulation really does a fine job. (1.5")
|
|
secharles
New Member
Posts: 24
Likes: 1
Currently Offline
|
Post by secharles on Jun 22, 2024 6:51:14 GMT -8
i really believe 70% of the framing rot comes from condensation on the backside of metal siding not leaks around penetrations. That cannot be overstated! We both agree on that point. I believe your 70% number is conservative. You have to figure out a way to stop, drastically reduce the warm, moist air from inside the trailer from working it's way to the inside of the cold aluminum skin where it condenses. John Palmer any old good tinsmith will apply a piece of 30# felt paper (asphalt impregnated) to wood sheathing before putting on his flashing. flashing will condensate atmospheric moisture or any which may breach the living space especially around vent pipes/ other penetrations. Q: why not take a step and staple a piece of felt paper onto the wall framing (not continuous/ just strips) prior to installation of metal sheathing-siding? it would add maybe 1# weight to the whole, and act as a barrier between the two dissimilar components (not usually a bad thing). recently, a manufacturer's repair technician (Marvin to be specific. i've learned we like specifics*) explained to me that a substantial amount of decomposition requiring sash replacement is attributed to their aluminum clad wood sash. the aluminum sweats, the wood to which it is clad soaks up & never has opportunity to dry, and 10 years later the homeowner is complaining about the difficulty of opening it and asks why the paint on the inside of the sash fails after a couple of years. *i forgot to ask the brand of paint; sorry.
|
|
John Palmer
Senior Member
![*](//storage.proboards.com/forum/images/stars/star_orange.png) ![*](//storage.proboards.com/forum/images/stars/star_orange.png)
Hi, From a vintage trailer guy located in Santa Ana, CA. It's good to see lots of activity here.
Posts: 1,706
Likes: 600
Currently Offline
|
Post by John Palmer on Jun 22, 2024 14:33:28 GMT -8
That cannot be overstated! We both agree on that point. I believe your 70% number is conservative. You have to figure out a way to stop, drastically reduce the warm, moist air from inside the trailer from working it's way to the inside of the cold aluminum skin where it condenses. John Palmer any old good tinsmith will apply a piece of 30# felt paper (asphalt impregnated) to wood sheathing before putting on his flashing. flashing will condensate atmospheric moisture or any which may breach the living space especially around vent pipes/ other penetrations. Q: why not take a step and staple a piece of felt paper onto the wall framing (not continuous/ just strips) prior to installation of metal sheathing-siding? it would add maybe 1# weight to the whole, and act as a barrier between the two dissimilar components (not usually a bad thing). recently, a manufacturer's repair technician (Marvin to be specific. i've learned we like specifics*) explained to me that a substantial amount of decomposition requiring sash replacement is attributed to their aluminum clad wood sash. the aluminum sweats, the wood to which it is clad soaks up & never has opportunity to dry, and 10 years later the homeowner is complaining about the difficulty of opening it and asks why the paint on the inside of the sash fails after a couple of years. *i forgot to ask the brand of paint; sorry. I see very little point in discussing "Brands of Paint". What is important is Types of Paint. On a vintage trailer due to the extreme temperature, and weather changes it only makes sense to me to use a refinish product rated for "exterior UV use" both inside and outside. A vintage trailer is about the most extreme application I could think of. On a "stick and tin" trailer construction I believe the consensus is to use a ridged Styrofoam to fill in the voids between the framing. It's best to use a reciprocating knife blade to cut the foam "without any mess". If you accurately cut the foam panels they can be a "press fit" into the framing. We use a HVAC foil tape to tape all of the seams to prevent the warm moist interior air movement through the wall to the cold outer skin. It might be overkill but I always use a breathable house wrap to prevent the air movement. This wrap goes on last, just before the metal skin siding is applied. The Styrofoam provides a stiff backer for the soft, very thin aluminum skin. Fiberglass, and Bubblewrap products do not offer the same protection. It's very easy to make the ridged Styrofoam curve by scarfing one side with a razor blade every inch or two. Your questions confuse me, "But then, I'm Old". I'm not sure if we are talking about rebuilding a vintage trailer, a car, or a house as you jump around. The same methods do not work in each case. All of the questions you have asked are covered in multiple past threads on VTT. The advantage to this site is the extensive archive of information that is available to you. For every past question you will be able to read several different viewpoints and listen to how different people addressed the same issue. John Palmer
|
|
secharles
New Member
Posts: 24
Likes: 1
Currently Offline
|
Post by secharles on Jun 22, 2024 16:03:09 GMT -8
sorry if it's hard to follow. no question, there's enough deteriorated trailers around for everybody to have one.
|
|