Water damage and restoring my Forest River Sandpiper

[beazleybub]

My wife and I plan on living as full time fivers within the next two years and recently bought a 2002 Forest River Sandpiper 26' fifth wheel. We bought it knowing that it has water damage and believe it can be repaired. I have decided to replace all of the exterior plywood because the water damage was fairly heavy to the nose and rear. Some of the roof is sagging on either end of the rig along with the celling. I'm positive I'll be replacing some roof trusses because of it.

My question is, do I repair the exterior plywood and framing first or, do I repair the roof first? I'll be doing the repairs outside and will be covering the rig with tarps to keep it from getting rained on.

My first thought was to separate the roof membrane from the filon sides and leave the roof and membrane intact and repair the walls first. Does this make sense? Replacing all of the exterior plywood will give me a good view of the studs and allow me to replace what's rotted. After the plywood goes back on, I will be gluing new filon on.

Thanks!

[beazleybub]

I have some new information:

I created a model of my camper in sketchup and calculated the square footage of the exterior panels minus the windows and such. Although my calculations are a rough guestimate, here are some figures for anyone curious about it.

Crane Composites says their filon glued to luan weighs between 15.2 oz. and 18.4 oz. per square foot depending on the thickness. At 443 square feet, the total weight of the filon and luan on my rig weighs between 421 lbs. and 509 lbs.

LP smartside says their composite siding weighs 20.5 oz. per square foot, so the lp smartside weighs in at 568 lbs.

There is only a 147 pound difference between the two. However, I am not counting the added weight of nails/screws and trim. I can only guess the nails and trim boards will add around another hundred pounds or so.

I have also created a sketchup rendering of the studs that will be used in the slide out. Sketchup allows me to create a future blueprint and also gives me a virtual space to experiment with reconstruction ideas.



As you can see in the image above, I have chosen to replace the stock single pane RV windows with actual dual pane vinyl mobile home windows manufactured by Kinro.

[beazleybub]

I have torn out most of the interior including the dinette and sofa. I have also torn out most of the interior panels and most of the cabinets. Five rear and two front trusses are toast. There is rot around the top of the slide out and the slide out itself will need to be completely rebuilt. The roof membrane and plywood will also need replacing. I have taken out all of the carpet and vinyl flooring. There are no current mold issues inside.

The bathroom and kitchen area is in very good condition with no signs of rot. The entire floor is good to go throughout the unit. I will be able to rebuild this unit and make it nice again. I'm relieved that I don't have to demo the bathroom or kitchen.

Here are a couple of images I took during the demo.

[MPI_Mallard]

Just a question,,, aside from the method your employing to re-build,, any mold issues???

[beazleybub]

I feel foolish, LOL. In my head, I pictured the trusses attached to a ledger, just like how decks are attached to houses.

[Dayle1]

beazleybub wrote:

What part of the wall is the top plate attached to? Hopefully the inside frame. I assume it will be due to the original skin being 1/8" or 1/4".

The top plate will be either a 1x2 or 2x2 and all the studs attach to it and the matching bottom plate. Interior and exterior siding will also attach to it just like they are attached to the stud faces.

[beazleybub]

DownTheAvenue wrote:

If you Filon sides, like you claim, you are dealing with delamination. Your unit is not stick built. The walls are vacuum glued and the whole wall is one integral unit. You MAY have studs in the walls, but it is not built like you are envisioning. Now, if you don't have Filon, but aluminium siding, then stick built may be a more appropriate term. Good luck to you.

In the end it does not matter how the wall was assembled. The only thing that matters is whether or not it can be re-sided. I did not intend this thread to become a who knows more contest. Everyone's opinion does matter here and I value any input, even if I may disagree. Everyone has their own experiences and wisdom that may or may not apply to a specific style of construction. Over the years, recreational vehicles have been built in several distinct and unique ways. I'm sure all of this information can apply in one form or another.

In other words, thanks for everyone's input. :C

[beazleybub]

Dayle1 wrote:

The wall will have a top plate and each roof truss will be attached to it. You have to remove the rubber roof and plywood roof decking if any truss needs to be replaced or repaired. Wiring and A/C duct will run thru the trusses, so repairing will be much easier than replacement.

What part of the wall is the top plate attached to? Hopefully the inside frame. I assume it will be due to the original skin being 1/8" or 1/4".

I have seen construction images where the wiring passes through a hole drilled in a truss. I would have a solution for that if I were to be forced to replace a truss completely. It would involve creating a notch and reinforcing the notch after the wires are passed up and into it. The A/C duct can be cut in half then re-assembled.

[Dayle1]

beazleybub wrote:

Still, my question remains unanswered though. I'm trying to determine how the roof trusses are mated to the camper. I'd like to leave the roof repairs for dead last if possible. Do I have to repair the roof first or can I repair the walls and siding first? Common sense tells me to fix the walls and siding first, so I may have answered my own question. 😄

The wall will have a top plate and each roof truss will be attached to it. You have to remove the rubber roof and plywood roof decking if any truss needs to be replaced or repaired. Wiring and A/C duct will run thru the trusses, so repairing will be much easier than replacement.

[Dayle1]

DownTheAvenue wrote:


If you Filon sides, like you claim, you are dealing with delamination. Your unit is not stick built. The walls are vacuum glued and the whole wall is one integral unit. You MAY have studs in the walls, but it is not built like you are envisioning. Now, if you don't have Filon, but aluminium siding, then stick built may be a more appropriate term. Good luck to you.

Not true, there are 3 basic types of wall construction and all can have smooth fiberglass skin. Vacuum laminated and pinch rolled are close in techniques, but hung wall is close to stick built and how mobile homes are built. The wall section is built with studs and interior skin, attached to the floor. Then insulation and wiring/plumbing is done. Finally, the exterior skin is glued to the studs and attached top and bottom. With hung wall construction, it is possible to re-skin rather than replacing the complete wall.

[DownTheAvenue]

beazleybub wrote:
I'm sorry but, you are mistaken. My rig is stick built, 2" studs, 16" on center.

With that said, I have decided to break the mold and use an alternative method to re-side my rig. I know weight is an issue, so after much research, I have decided to use "LP SmartSide 38" panels. These panels do not require a backer and can be nailed or screwed directly to the studs themselves. The (0.315-in x 48.563-in x 95.875-in) panels only weigh 41 pounds each, which makes them lighter than the plywood they will be replacing. The panels are not expensive, at $26 each I can completely re-side my entire unit for under $600. The only issue installing them will be with the nose of the trailer. The panels cannot be bent, so I will have to either use a different siding for the nose radius, or reconstruct the nose to a flat profile.

If you Filon sides, like you claim, you are dealing with delamination. Your unit is not stick built. The walls are vacuum glued and the whole wall is one integral unit. You MAY have studs in the walls, but it is not built like you are envisioning. Now, if you don't have Filon, but aluminium siding, then stick built may be a more appropriate term. Good luck to you.

[beazleybub]

You are right, I do plan on pre-drilling the holes. I'll be using a pneumatic nail gun, so I will have full control of the beating I give the studs. This panel has to be mounted vertically, as it is not designed to be mounted any other way. And to be perfectly honest with you, we don't plan on moving this camper very much. It's likely we will stay put for several years. We plan on living on the North Carolina coast and there are literally dozens of RV sites up and down the shoreline.

Regarding tiny houses and flex, please see my edit in the above post about seismic activity.

Don't get me wrong, I appreciate your opinion. Just in my particular case, this is way more cost effective for a 15 year old camper. I will have less than $6,000 invested for a total overhaul and I will be happy with that.

Still, my question remains unanswered though. I'm trying to determine how the roof trusses are mated to the camper. I'd like to leave the roof repairs for dead last if possible. Do I have to repair the roof first or can I repair the walls and siding first? Common sense tells me to fix the walls and siding first, so I may have answered my own question. 😄

[Dayle1]

beazleybub wrote:
Found some new information. Dayle1 can you give me your source for what you said the filon weighs with luan backing?

Dayle1 wrote:
Actually, the "plywood" used is either a single layer or two layers of 1/8 in lauan plywood. A 4x8 ft section will weight about 22 lbs if two layers are used, so it is lighter than the panels you are considering

I found some information from Crane Composits website (The people who make filon.) that suggests filon with luan backing weighs anywhere from 0.95lb/ft² to 1.15lb/ft² depending on which type you choose. (They make different thicknesses.) The lightest they manufacture is 0.95lb/ft² and a 4X8 sheet would weigh around 30.4 pounds. That's only 10.6 more pounds a sheet. So if the factory finished side of my camper weighs 267 pounds and my new side weighs 198 pounds, my new siding would only be 69 pounds heavier. By switching to LP SmartSide panel my rig will gain less than 200 pounds.

I don't see enough weight difference to cause an issue.

Simple, my number was for the wood only.

[Dayle1]

beazleybub wrote:

Not to sound argumentative but, why then are hundreds of people in the tiny house community using LP SmartSide panels? The panel I chose is structural and suited for 16" on center framing.

Even houses "flex" on a daily basis. With proper installation and sealing, I do not believe it will be an issue. I will be also wrapping my rig with tyvec wrap. This will greatly reduce any chance of future water damage.

Residential houses do not move and tiny houses move very little, very short distances and at slower speeds then the typical RV. Finally, fifth wheels flex a tremendous amount every time they are connected/disconnected as the pin weight transfers between the pin and the landing gear, a substantial distance.

For the panels, use screws or ring shank nails with a nail gun. Using a hammer will be too many hammer blows and loosen other attachment points. The studs are 2x2 at most, more likely to split than a 2x4, both during installation and later road flexing. Pre-drilling the holes would be a good idea and keep them centered on the stud. Most strength would come from installing the 4x8 panels horizontally with staggered joints which puts less stress on any single stud. Or, double stud the joint studs if the panels are installed vertically.

Finally, if the water damage is minimal and localized, you might consider repairs from the inside rather than outside.

[beazleybub]

Found some new information. Dayle1 can you give me your source for what you said the filon weighs with luan backing?

Dayle1 wrote:
Actually, the "plywood" used is either a single layer or two layers of 1/8 in lauan plywood. A 4x8 ft section will weight about 22 lbs if two layers are used, so it is lighter than the panels you are considering

I found some information from Crane Composits website (The people who make filon.) that suggests filon with luan backing weighs anywhere from 0.95lb/ft² to 1.15lb/ft² depending on which type you choose. (They make different thicknesses.) The lightest they manufacture is 0.95lb/ft² and a 4X8 sheet would weigh around 30.4 pounds. That's only 10.6 more pounds a sheet. So if the factory finished side of my camper weighs 267 pounds and my new side weighs 198 pounds, my new siding would only be 69 pounds heavier. By switching to LP SmartSide panel my rig will gain less than 200 pounds.

I don't see enough weight difference to cause an issue.