soft floor

[tlava]

Hi Folks--

Possibly buying an '86 shorty ('18) )Sunrader: there's a soft area on the coach floor, about 2' in the kitchen area--any experience with this? could it be from an old plumbin lieak? skylight? (there is one a bit forward of the area). Wondering if this is reason to stay away, or really not something to worry about. An easy repair?

what is the structure of the floor? is it plywood with some kind or coating unerneath (on the undercarriage)?

Also, as I recall, the SR is coach is two-piece molded fiberglass, so no wood armature or frame structure to worry about (i.e., if leaks develop in a skylight or window, I wouldn't have to worry a roof or wall collapsing)? Do I have this right?

Thanks in advance for your always excellent advice!

[flatspin]

A soft spot on the floor isn't necessarily a deal breaker, but I'd certainly want to understand why it has occurred. The structure of the original floor doesn't lend itself to repair per se, but it is entirely possible to re-skin the floor using plywood, so there are remedies. I wouldn't call it difficult from a skills standpoint, but just pulling up the carpet is a huge chore because it is attached with an obscene number of staples.

You just want to know that there isn't a persistent water issue that will continue to rot the floor after you've made the repair.

And yes, the walls and roof are made of two fiberglass shells which provide the exterior skin and the primary structure. The coach can't rot the way a stick frame would, but water leaks are still a pain. Goes with the territory.

-andrew

Hi Folks--

Possibly buying an '86 shorty ('18) )Sunrader: there's a soft area on the coach floor, about 2' in the kitchen area--any experience with this? could it be from an old plumbin lieak? skylight? (there is one a bit forward of the area). Wondering if this is reason to stay away, or really not something to worry about. An easy repair?

what is the structure of the floor? is it plywood with some kind or coating unerneath (on the undercarriage)?

Also, as I recall, the SR is coach is two-piece molded fiberglass, so no wood armature or frame structure to worry about (i.e., if leaks develop in a skylight or window, I wouldn't have to worry a roof or wall collapsing)? Do I have this right?

Thanks in advance for your always excellent advice!

[linda s]

Don't think I've ever seen a shorty Sunrader without a soft spot in exactly that place. Greg has a write up somewhere on this site that describes how how fixed his.

Basicaly took up the carpet and put down 1/2 inch plywood. I didn't want to lose headroom so I used 1/4 inch marine grade and then put c channel rods used for

shelving underneath for more support. Sunrader brochures are in the toyota-camper site on Yahoo groups and include a drawing of how the floor is put together. Plywood, foam another thin plywood

and covered underneath with thin steel. No i it leaked you coach frame strength does not degrade. I have 2 Sunraders. The other one is soft too but not too bad so I haven't done

anything yet. 7 years later it is unchanged, no softer

LS

Hi Folks--

Possibly buying an '86 shorty ('18) )Sunrader: there's a soft area on the coach floor, about 2' in the kitchen area--any experience with this? could it be from an old plumbin lieak? skylight? (there is one a bit forward of the area). Wondering if this is reason to stay away, or really not something to worry about. An easy repair?

what is the structure of the floor? is it plywood with some kind or coating unerneath (on the undercarriage)?

Also, as I recall, the SR is coach is two-piece molded fiberglass, so no wood armature or frame structure to worry about (i.e., if leaks develop in a skylight or window, I wouldn't have to worry a roof or wall collapsing)? Do I have this right?

Thanks in advance for your always excellent advice!

[bajadulce]

The sunrader floor is a composite construction. The individual parts of these composites are bonded together and provide support as a whole that the individual parts themselves would not be able to. If you were to stand on a piece of 1/4 inch plywood that spanned 4', you would naturally expect to see flex. That same span with foam alone and you would fall right through. These individual materials bonded together form a strong surface; as long as the bonds remain laminated together.

The problem however, is that the dissimilar materials of the sunrader make for poor bonding (especially highly porous plywood to foam). More modern composites such as Nidacore use a petroleum to petroleum product such as a sheets of reinforced plastic sandwiched between a honeycomb cell (think corrugated cardboard).

The sunrader engineers miscalculated by expecting their composites to withstand up to heavy traffic while spanning the 4'or so that is between the cab and the crossmember support that runs above the vicinity of the gas tank. Just bisecting this span with a single support would have made all the difference in the world.

And so your floor has suffered delamination. A soft floor doesn't necessarily spell water damage when dealing with composite construction. The floor is flexing because the top layer of plywood is now "spanning alone".

The fix:

As Andy mentioned you can't reglue the materials back together. The easiest solution is to try and add another "composite skin" in the form of a plywood patch. Obviously the thicker the plywood you'll feel less flex. And anything larger than the 1/2" as mentioned Greg used would be overkill. Unless you're putting an entire new layer atop your floor, you'd need to smooth out any transition area around the perimeter of the patch and floor that would effect foot traffic.

If the area isn't too bad, you might try laminating a few layers of fiberglass to stiffen up the plywood pulling support from surrounding areas as well. A thin layer of fiberglass is amazingly strong. I would lay a layer of resin to fully cure first tho before applying the cloth to act as a primer of sorts. plywood has a way of really soaking up fluids.

The best fix would be to cut out the section of floor and add support underneath as Linda has described and done. I did this in my original sunrader and cut out the galley (about 2x4') between the cab and the first support (under gas tank). The foam was gouged out where new support pieces were run lengthwise between the 2 crossmembers. If I remember correctly, there wasn't a lot of space, and so the supports were more width based than vertical.

Gluck w/ your project should you purchase this rig AND use the fact that there is a good chance this soft spot in the floor is NOT attributed to water damage as buying leverage.

[linda s]

One other thing. The floor I repaired had previously been covered by a 3/4 inch piece of plywood to support it. Because you can't get this extra support wall to wall

and because it weighed so much it created a rubber band effect. Bouncing up and down in the middle of the rig causeing all kinds of vibration while driving.

A little flex in a camper with a flexible fiberglass shell is a good thing. I would not advise cutting out any of the old original plywood floor cause of that foam underneath.

Nothing to screw another peice of plywood too. I drilled a few small holes and poured resin into them and all over the floor. Made a nice hard surface to attach the new plywood to.

LS

Don't think I've ever seen a shorty Sunrader without a soft spot in exactly that place. Greg has a write up somewhere on this site that describes how how fixed his.

Basicaly took up the carpet and put down 1/2 inch plywood. I didn't want to lose headroom so I used 1/4 inch marine grade and then put c channel rods used for

shelving underneath for more support. Sunrader brochures are in the toyota-camper site on Yahoo groups and include a drawing of how the floor is put together. Plywood, foam another thin plywood

and covered underneath with thin steel. No i it leaked you coach frame strength does not degrade. I have 2 Sunraders. The other one is soft too but not too bad so I haven't done

anything yet. 7 years later it is unchanged, no softer

LS

[tlava]

Hi Folks--

Thanks for that! a lot of useful information... so it appears my choices are to cut out the area, or not cut it out but go over it with say a 1/4 " ply, and angle-out the transitions. Not sure I follow exactly about the supports--these would connect to the chassis frame somehow, if the whole floor were cut out? or would I just cut out the top section of floor (first layer above foam)? and somehow inseat supports? Would removing the first layer, then adding a thin ply and encasing that in fibber glass work,or easier yet just glassin over what is already there? a few layers of mesh and glass would probably be stronger and much thiner than plywood? I've fixed rotted floorboards in Toys ( and others) this way before...

[bajadulce]

Sorry was a little ambiguous as to what to cut out. Yes, the top layer of floor was cut out, basically the galley area from bathroom to fridge.

The plywood floor itself wasn't damaged at all (might be the same with your situation), it just had delaminated. There were pictures posted of the repair in my ongoing thread, but it appears they aren't visible as the site they were hosted on is gone. Will try to upload them again when I have access.

I do seem to recall that there only being one cross member somewhere around the gas tank. The floor between the cab and this cross piece is totally suspended without any support. Maybe it was 4' or maybe it was only 3'. Either way, it was a long way and nothing was going to save my floor other than an additional sheet of substantial thickness plywood on top or the section of plywood floor had to be cut out this entire length so as to run a support piece from the one cross member to the front cab.

Yes, Linda is right, there is nothing to rescrew the plywood down other than the new joist that was run lengthwise after gouging out the foam to make room for the new support. If I remember, the foam is only about 3/4" thick and so nothing can really be ran in a vertical fashion that will garner strength in a true "joist" configuration. And so WIDTH is your next best thing. I used a 1x6"ish piece of cabinet hardwood (tho some decent pine shelving free of knots would be sufficient). I also ripped a small piece that was tucked under the existing plywood around the perimeter and extended out a bit (had to gouge out a little foam there as well). This formed a nice lip that allows the plywood to be screwed back down around the perimeter. The section of plywood was put back and glue/screwed down and a sheet of fiberglass cloth applied to that just for a little more strength and water proofing etc.

Of course this was to fix a complete basket case of a floor. I would try your idea to add some glass and see how that goes. Was there any dry-rot? Or just a delaminated floor? Sounds like you've had some success with repairing a floor before.

Is cutting out a section of floor, gouging out a strip of foam to put in a support the best idea? Depends I guess. Nothing wrong with putting an additional piece of 1/2" plywood atop the existing 1/2" floor (makes for almost an inch of flooring). How much does it weigh? probably not enough to worry about. I'd suggest just the entire "livable" area and not even deal with any transition areas. can't be that much square footage.

The key tho if you do add another layer of floor is to make sure it bonds to the existing floor to fully take advantage of whatever composite construction integrity of the original floor remains + garner some strength from the existing floor as if it was another "ply". I wasn't sure what Linda was referring to when she said the 3/4 plywood was "bouncing" around. Sounds as tho it wasn't attached to the existing floor? I would use some construction adhesive and screw the heck out of it. Ok so you won't be able to take it back up in the future with gluing, but when is it necessary to separate "plys" of plywood? And that's your goal with adding a new sheet of plywood atop the existing; to create a new "ply" to the existing plywood.

Sounds as tho Linda used epoxy to bond the new sheet of plywood to the existing plywood which is a good idea.

I'll try to get some pictures of my old floor reuploaded.

[mulwyk]

Hi Folks--

Possibly buying an '86 shorty ('18) )Sunrader: there's a soft area on the coach floor, about 2' in the kitchen area--any experience with this? could it be from an old plumbin lieak? skylight? (there is one a bit forward of the area). Wondering if this is reason to stay away, or really not something to worry about. An easy repair?

what is the structure of the floor? is it plywood with some kind or coating unerneath (on the undercarriage)?

Also, as I recall, the SR is coach is two-piece molded fiberglass, so no wood armature or frame structure to worry about (i.e., if leaks develop in a skylight or window, I wouldn't have to worry a roof or wall collapsing)? Do I have this right?

Thanks in advance for your always excellent advice!

'84 Sunrader 18' Floor Ok but wife said I had to remove that horrid, musty old stapled on carpet. I used 1/2" plywood secured with #8 flathead stainless sheetmetal screws every 8", then laminate flooring over the top. Very sturdy, but I lost 3/4" headroom.

[Gulfstream Greg]

Sunrader brochures are in the toyota-camper site on Yahoo groups and include a drawing of how the floor is put together.

LS

You might be surprised to see what we have here in the "Files and Photos" section. http://toyotamotorhome.org/forums/index.php?app=gallery&module=cats&do=sc&cat=48

Bajadulce and linda s are right on the money. The best and easiest fix is to put down 1/2 inch (I think 1/4" is not enough) plywood over the existing. I did not bond the 1/2 inch to the original flooring but it really should be with something like liquid nails. You are in a sense creating a 3/4 inch thick area in the open areas of the floor, under the cabinets and shower remain 1/4 inch and that 1/4 inch is what is supporting the new 3/4 open areas so the less flex you can create in that open area the better. The idea is to eliminate the flex as much as possible. As said, building a new robust support system under the floor is another option. Both together would be the best fix.