snail powered Posted August 15, 2013 Share Posted August 15, 2013 The roof structure of a Sunrader was designed and built as a "structural insulated panel". When you remove the sheet of plywood, the foam and other elements that have been adhered to the upper fiberglass surface of the Sunrader you will have destroyed its engineered ability to act as an integrated load bearing unit. So do not gut out those materials as part of your remodel unless it is absolutely essential to do so. As the wall paneling is not stapled or glued to the roof panel structure you can remove the wall paneling, insulation and furring strips without removing or impacting the ceiling system. Logically thinking about how the builders of the Sunrader created that Structural Insulated Panel while using the fiberglass roof as the exterior layer indicates the following. That work would have been done before the upper half of the fiberglass shell was removed from the mold. The mold would have been used to keep the fiberglass supported in perfect conformation of its curved shape.t The materials will have been added in one layer at a time using gravity and additional weights to help achieve a uniform bond. The materials would have been left in that weighted condition until the adhesives fully cured. You will not have a mold to help you keep the shape of the roof in its intended conformation and you will not have gravity working for you. You would find it very difficult while working overhead to add in the layer of fiberglass that is just above the bottom layer of plywood, and against the lower edge of the insulation foam layer. Peeling ceiling wall paper and discoloration is something that can be fixed without removing that essential ceiling structure. Small areas of delaminating plywood can also be repaired without removing the ceiling structure. Redecorating the lower surface materials is fine. However removal of the structural components because you want to redecorate is creating a major engineering headache and expense that will have to be solved. It is only if you have a major failure of the ceiling where the foam and other layers have come apart from the upper fiberglass surface that you should take out the ceiling components as part of your Sunrader remodel. If you are going to add in an additional support beam to help hold up an air conditioner do it by removing only a small section of the ceiling panels, just enough to slide your beam in up against the fiberglass. Be sure your new beam is well bonded to the fiberglass on the roof and to the adjacent insulating foam as well as to the lower surface of the plywood panel to fully integrate it into the Structured Insulated Panel system. If you are going to pursue a complete gut job on a Sunrader then before removing any part of the ceiling you should have already designed your new roof support system. You should have all the materials on hand so you can immediately install them. The fiberglass of the roof will not be able to keep its shape for very long as its own weight will begin to deform it. Do lot leave it out in the hot sun in an unsupported condition. Do not climb onto the roof without the support structure in place. Quote Link to comment Share on other sites More sharing options...
RHS Posted August 17, 2013 Share Posted August 17, 2013 I have rebuilt 4 sunraders. The 1st one had 3 feet of snow on it & the roof vent was gone, 3" sag in the roof. The upper cabinets were on the floor. Removed every thing 1X2s 1/8 " longer than the span (to maintain arch) w/polyurethane construction adhesive pushed up into place held over night by supports from floor, glued 3/4" foam between 1X2s, attached paneling to 1X2s. Still great after 4 years. Quote Link to comment Share on other sites More sharing options...
85Diesel Posted August 24, 2013 Share Posted August 24, 2013 What was the spacing on the 1x2's? Quote Link to comment Share on other sites More sharing options...
RHS Posted August 24, 2013 Share Posted August 24, 2013 I think I went 16". The upper cabinets if installed properly support the roof also. I have had to glue framing to roof on several over the bed. All construction adhesives are not made the same. I used polyurethane but some of that has changed also. Quote Link to comment Share on other sites More sharing options...
snail powered Posted August 25, 2013 Author Share Posted August 25, 2013 I think I went 16". The upper cabinets if installed properly support the roof also. I have had to glue framing to roof on several over the bed. All construction adhesives are not made the same. I used polyurethane but some of that has changed also. How are you constructing and installing the upper cabinets to give support to the roof? The original cabinet installation on a Sunrader only gives marginal support to the roof. Engineering wise they are contributing very little to supporting the roof as they are only tied in to the roof at the front edge of the cabinets. Remember that the Sunrader cabinets are not constructed with a back on them or strong sides on them so they do not have the strength of a typical cabinet used in a kitchen. Basically they are L shaped, front and bottom only rather than being a box. The front is not solid, just a face frame, mostly open space. The bottom is a thin plywood panel screwed to the face frame front and a 3/4 wide rail at the back. It is the ceiling that is supporting the cabinets, not the other way around. When you think about the fact that the cabinet cantilevers out from the wall at that bottom strip, then structurally it is not supporting a lot of the weight of the cabinet, in fact it is incapable of supporting the full weight of empty cabinets, mostly it is just holding the cabinet against the wall and helping to support the weight of cabinet contents that are close to the wall. The two ends of the cabinet are not structurally strong, they do little in the way of support. Therefore the screws going into the ceiling panel are supporting much of the weight of the contents of the cabinet. Plus of course the weight of the cabinet doors as well as the face frame. This means the ceiling panel and roof is probably supporting most of the weight of the cabinets and contents. The cabinets do provide some point load stiffness to the roof top (compression load from above) as the front edge will help to transfer the load fore and aft along the length of the face framing (particle board) which is tied into the rear framing (particle board) with a piece of 3/16" plywood with a half dozen screws and one or two particle board cross members (particle board). But in reality original Sunrader cabinets are a fairly flimsy structure. My upper cabinets were suspended from the ceiling with about half dozen screws which going into the 3/16 plywood of the ceiling plus the layer of fiberglass laminated to the top of that plywood. Above that layer of fiberglass is a piece of insulation foam which of course provides no support when screws are put into it. As part of my Sunrader remodel I will be adhering in a long wood cleat just under the edge of the ceiling panel where it meets the fiberglass Z shape coming up from the walls. It might help to keep the ceiling panel compressed up to the roof (along that edge only) and will give some minimal support to offset the load from the cabinets pulling down on the ceiling panel. Basically a safety net measure to reassure myself rather than something that will actually support the roof and cabinets in any significant way. I will use western red cedar for that cleat as it is light weight but strong enough for the purpose. I will have to figure out the bevel angle for the top edge as that is not a 90 degree corner. Quote Link to comment Share on other sites More sharing options...
RHS Posted August 25, 2013 Share Posted August 25, 2013 Karin You are right the cabinets do provide a lot of support for the roof. One of my biggest complaints with gardiner pacific was the use of particle board for framing. I've used the cabinet fronts for a pattern & some 4mm plywood for new fronts. It amazed me the different feel on the roof with and without the cabinets installed. With 2" wide cross strips you can get 2 scews on each. The end caps helped to stiffen the "box" of the cabinets. I put the cross pieces a little closer together than the original so more screws to hold up cabinets. I wish I had kept some records. I am not an engineer just an old millwright/fabricator. I am sure there are people who know better than I. Good luck with your remodel. Quote Link to comment Share on other sites More sharing options...
snail powered Posted August 25, 2013 Author Share Posted August 25, 2013 Karin You are right the cabinets do provide a lot of support for the roof. One of my biggest complaints with gardiner pacific was the use of particle board for framing. I've used the cabinet fronts for a pattern & some 4mm plywood for new fronts. It amazed me the different feel on the roof with and without the cabinets installed. With 2" wide cross strips you can get 2 scews on each. The end caps helped to stiffen the "box" of the cabinets. I put the cross pieces a little closer together than the original so more screws to hold up cabinets. I wish I had kept some records. I am not an engineer just an old millwright/fabricator. I am sure there are people who know better than I. Good luck with your remodel. I said the cabinets do not provide a lot of support for the roof. That the roof supports them. But that they do provide some stiffening strength to the roof along the length of the cabinet frame. A very poorly designed box beam truss lacking in diagonals on the face frame side. It is also not well tied into the structure of the other sides. . The passenger side on my shorty is not as bad as it fairly short and has a closet at one end and the back wall at the other end. That side is not too bad of a box beam span but still lacking on the cabinet face. Then passenger side upper cabinets, well its close to useless, no support from underneath near the door so the cabinet is just pretty much just hanging up there with a few screws. It would be much improved by an end panel that carries the load all the way down to the floor. There is no blocking behind that wall panel area behind the stove and sink below the lower edge of the upper cabinet. No blocking around the door frame for the paneling to be stapled or glued to. The only vertical blocking is part of the section around the window. And on that side of my coach it does not go all the way down to the floor. What they did was count on the cabinet for the sink/stove to hold the wall paneling in position by screwing that cabinet to the paneling. I took basic measurements from my original upper cabinets. I recreated the basic shape of them in a 3DCAD model. Then using the position of the front face and rear rail I created a design for my new upper cabinets. That way the rear cabinet rail will still hit the wood furring strip used to mount the original cabinets and also attach in the same position on the ceiling. I am not an engineer but I can see how a structural system works as a unit and how the loads are supported. I started looking at building blueprints as a very wee little lass who later drafted buildings and then went on to working on jumbo jets and then hanging around boat building yards. Of course watching shows like "This Old House" and reading "Fine Home Building" helped me understand things like SIPs, what they are, how they are made, what they can do. Quote Link to comment Share on other sites More sharing options...
zero Posted September 11, 2013 Share Posted September 11, 2013 I'm not sold on the use of SIPs in anything that sits outdoors unless rot-proof materials are used. I've see a few Sunraders in the junkyard with roofs sagging - as well at many other RVs with SIP roofs and floors. As I recall, the idea of SIPs came from bird beaks years ago. Someone noticed that some sea birds had huge, ultra strong and ultra light beaks that were made in layers of soft, lightweight materials. Soft spongy core and hard thin outer layers. Put together as a unit they are extremely strong. SIPs work on a same idea as bridges made out of toothpicks (sort of). Very strong when everything is intact. Not so strong when a few components degrade. I suspect no RV company wants their products to last too long - or who the heck would buy new ones? SIP make a strong lightweight system until trapped moisture destroys the integrity. Here in NY where many RVs sit outside snow-covered in the winter - they can rot pretty fast. Often there is no venting inside for the walls and once wet they tend to stay wet and rot. I was just looking at the sagging roof on a Winnebago Phasar that got water intrusion from the air conditioner hole. Fiberglass on the outside, polystyrene in the middle, and 1/4" plywood on the inside - all glued together. But once rotted - I'm not sure how the heck I'd fix it. Kind of wish it had some metal tubing framework to work from. My wife's parents built a new house in northern Michigan about 15 years ago. First house in town to be built with SIP panels. The big claims for these panels were/are the high R value along with having Cathedral ceilings with no venting needed. Polyiso Insulation supposedly is bonded to the OSB on both sides and therefore - no moisture can get in. NOPE. Now they've got problems. Roof had seepage, water got into the OSB and rotted it in places - and they've got a roof on their house with NO rafters for support. I suspect the fix is going to be very complicated and expensive. If it was a conventional house with rafters and sheathing - it would be easy. I'm not bad-mouthing Sunraders here. I think they are one of the best when it comes to roof construction. That being said, in some ways I like something with metal framework up top. And - maybe Sunrader has some - I don't know? I took a chainsaw today and cut a hole in the floor panel in a Chinook . I did this to get at the gas tank fuel pump and sender. I'm junking the Chinook anyway so no big deal. Kind of interesting to see the three-ply "early" SIP they used. 1/4" plywood on top, a honeycomb of something like cardboard in the middle with cells of trapped air, and another layer or 1/4" plywood on the bottom. All heavily glued and amazingly strong and light (until it rots). Quote Link to comment Share on other sites More sharing options...
Mikesta Posted September 12, 2013 Share Posted September 12, 2013 Completely gutted the 77 camper... I'll have to go take a look-see but I know the shell is all the same width 3/16ths per that picture above. I've also seen some good youtube videos of a guy re-arching his roof of his sunrader. I'm pretty sure it will take some thinking, but not impossible to do. I've owned over 10 Sunraders and still have a lot to learn. Its good reading that some sturdier cabinetry work also strengthens the roof a tad. Quote Link to comment Share on other sites More sharing options...
Sunnynshare Posted September 12, 2013 Share Posted September 12, 2013 Weren't there some posts about the roof thickness around the air condition opening in this thread or am I finally going round the bend? Since I have a Sunrader I absorb such information. Kim Quote Link to comment Share on other sites More sharing options...
snail powered Posted September 12, 2013 Author Share Posted September 12, 2013 I took a chainsaw today and cut a hole in the floor panel in a Chinook . I did this to get at the gas tank fuel pump and sender. I'm junking the Chinook anyway so no big deal. Kind of interesting to see the three-ply "early" SIP they used. 1/4" plywood on top, a honeycomb of something like cardboard in the middle with cells of trapped air, and another layer or 1/4" plywood on the bottom. All heavily glued and amazingly strong and light (until it rots). JD, I hope you will move the Chinook photos and info about your floor project into their own thread. They are interesting to see but I hate to see them get lost in a thread about the roof on Sunraders. No one would ever think to look here for them as it is a Chinook and it is the floor rather than the roof. Anyway it is not an SIP if it contains no insulation which your example does not. But it is a cored panel Quote Link to comment Share on other sites More sharing options...
snail powered Posted September 12, 2013 Author Share Posted September 12, 2013 Weren't there some posts about the roof thickness around the air condition opening in this thread or am I finally going round the bend? Since I have a Sunrader I absorb such information. Kim Linda posted a photo showing it in her Sunrader. The fiberglass looks to be built up in thickness to around 1/2" along the edge and it also has some plywood inserted around the perimeter of the opening as well. Seems sensible as it would certainly keep the roof flatter and provide some structure for screws from the vent or an air conditioner to grip into. The roof thickness around the vent opening in my 1980 Sunrader has not been built up or modified in any way. It is simply the 3/16 fiberglass, 5/8 foam and 3/16 plywood SIP. All layers are visible at the cut edge of the opening. I think when I install a new vent with powered fan someday in the future that I will router plane back the foam about 3/4" deep and then epoxy in some 3/4" by 5/8" wood strips. Not so much to stiffen the opening as to provide a better structure for the screws to bite into. I have some Cherry wood on hand and it is actually very rot resistant as well as being nice and hard for good screw holding. Not light weight but then again I am not putting in very big pieces of it and it won't weigh much more than plywood. I will not use plywood there as it might delaminate in that leak prone area. You can see the delamination already happening in the photo of Linda's vent opening. You don't need a power tool to trim back the foam to a set depth. You can make in a couple of minutes a simplified version of the tool in the link below. Mine will be just a block of wood with a hole drilled in it and a sharpened Allen wrench epoxied in so it projects 3/4". http://paulsellers.com/2012/03/not-so-poor-mans-router-really-works/ Quote Link to comment Share on other sites More sharing options...
snail powered Posted September 12, 2013 Author Share Posted September 12, 2013 Completely gutted the 77 camper... I'll have to go take a look-see but I know the shell is all the same width 3/16ths per that picture above. I've also seen some good youtube videos of a guy re-arching his roof of his sunrader. I'm pretty sure it will take some thinking, but not impossible to do. I've owned over 10 Sunraders and still have a lot to learn. Its good reading that some sturdier cabinetry work also strengthens the roof a tad. Our forum member Waiter did a great posting on making new beams for a Sunrader roof. Honestly it is the best method of all to make strong but lightweight beams for the roof. If you want more of an arch you can cut that on a bandsaw. It is nice to have wood up inside that beam for screws to grab into. Scroll down to posting number 6 in this thread link http://toyotamotorhome.org/forums/index.php?showtopic=5086 Quote Link to comment Share on other sites More sharing options...
zero Posted September 12, 2013 Share Posted September 12, 2013 . I have some Cherry wood on hand and it is actually very rot resistant as well as being nice and hard for good screw holding. Not light weight but then again I am not putting in very big pieces of it and it won't weigh much more than plywood. I will not use plywood there as it might delaminate in that leak prone area. You can see the delamination already happening in the photo of Linda's vent opening. I don't know what species of cherry you've got. Around here in NY and MI, any cherry we have rots fast and has little resistance from decay. Black Cherry is the most common around here and useless when used in environments with moisture. Makes nice flooring and furnture though and also good for firewood if kept covered. White Oak, Tamarack-Larch, and White Cedar are the most common rot-resistant woods I know of here in the north-east. With boat-building - white oak is a common choice since it is rot resistant and very strong. Quote Link to comment Share on other sites More sharing options...
snail powered Posted September 12, 2013 Author Share Posted September 12, 2013 I don't know what species of cherry you've got. Around here in NY and MI, any cherry we have rots fast and has little resistance from decay. Black Cherry is the most common around here and useless when used in environments with moisture. Makes nice flooring and furnture though and also good for firewood if kept covered. White Oak, Tamarack-Larch, and White Cedar are the most common rot-resistant woods I know of here in the north-east. With boat-building - white oak is a common choice since it is rot resistant and very strong. D are you trying to educate a professional wood worker who builds outdoor structures on the subject of rot resistant wood? My first trip in my RV was spent here http://nwboatschool.org/ I walk through a boat repair yard on the way to my workshop space. That was convenient the other day when I needed to buy a yard of peel ply. That fact that cherry is rot resistant seems to have dropped out of the common knowledge about woods in last 100 years or so. So it is not too surprising that you think I don't know what I am talking about I bet you did not know that black walnut is also rot resistant, another loss of onetime common knowledge of our wood species. list of native American woods that are rot resistant. there are two sources here. Thumbnail views of the lists are at the bottom of this post for your convenience. http://warnell.fores...=326[]=14 Tom Lathrop, professional boat builder, writing on the use of cherry: Tom Lathrop 03-27-2007, 02:47 PM Black cherry is a very good wood for boatbuilding. Rot resistance is of the same order of white oak as are most other properties. Most strength characteristics are also of the order of white oak other than hardness which shows less impact resistance of cherry. I have used it for rub rails where it imakes a handsome alternative to oak and is tougher than mahogany. I use cherry or mahogany on interior trim instead of teak. Historic Replicas of New York and Maine built boats that used Black Cherry http://www.marinij.com/marinnews/ci_24023732/lib-at-large-restoration-hardware-founders-new-venture Quote Link to comment Share on other sites More sharing options...
zero Posted September 12, 2013 Share Posted September 12, 2013 JD are you trying to educate a professional wood worker who builds outdoor structures on the subject of rot resistant wood? My first trip in my RV was spent here http://nwboatschool.org/ I walk through a boat repair yard on the way to my workshop space. That was convenient the other day when I needed to buy a yard of peel ply. That fact that cherry is rot resistant seems to have dropped out of the common knowledge about woods in last 100 years or so. So it is not too surprising that you think I don't know what I am talking about I bet you did not know that black walnut is also rot resistant, another loss of onetime common knowledge of our wood species. list of native American woods that are rot resistant. Thumbnail view of the list is at the bottom of this post for your convenience. http://warnell.forestry.uga.edu/service/library/index.php3?docID=326&docHistory[]=14 Tom Lathrop, professional boat builder, writing on the use of cherry: Tom Lathrop 03-27-2007, 02:47 PM Black cherry is a very good wood for boatbuilding. Rot resistance is of the same order of white oak as are most other properties. Most strength characteristics are also of the order of white oak other than hardness which shows less impact resistance of cherry. I have used it for rub rails where it imakes a handsome alternative to oak and is tougher than mahogany. I use cherry or mahogany on interior trim instead of teak. I'm not trying to "educate" anyone. you seem to have a huge chip on your shoulder. I made a simple statement of fact for trees here where I live in the Northeast, central NY. I too have been woodworking most of my life. Iv'e been hired to build rot-resistant structures in state parks where pressure-treated woods were not allowed (Adirondacks). My father-in-law is a lifelong wood boat builder. I also own a farm and live in a dairy farming area where wood choices for fence posts show which ones rot fast - and which ones do not. Note I qualified my statement about the native cherry trees in my area and have no idea what species or cultivars you were referring to. Around here - a black cherry fence post is lucky to last 5 years, whereas I've got some white oak that is over 15 years old and still pretty good (except for the tips). I've told that black cherry can vary a lot by it's age and area where grown - just like Eastern and Canadian Hemlock does. I have no knowledge of what cultivars of trees you have in your area, nor do I know your weather. Since you claim to know your woods - then you ought to know -that generally speaking - in my area (which I clearly noted) you can break them down into four numbers. #1 being the most rot resistant and #4 being the least. You should also know that same-species trees can vary a lot by region and age. #1 Black Locust, Yes, Osage, American Chestnut #2 White Oak, Cedar, Redwood, Sassafrass, Catalpa, certain cultivars of Black Cherry #3 Honey Locust, White PIne, LongLeaf Pine (note our local White Pine rots very fast) #4 White Ash, Basswood, American Beech, Birch, Eastern Hemlock, Pignut Hickory, Red Oak, Red, Hard, and Black Maple, Yellow Poplar Besides all that - there are other considerations. Weight, strength, and how tight the grain is. One reason why white cedar can be a "pain in the (*ss" because it splits so easy. The local Iroquois/Mohawk Indians used to use white birch for their weaker but light "throw-away" canoes that also rotted fast, and American Elm for the ones they wanted to last longer (but were harder to carry). Quote Link to comment Share on other sites More sharing options...
snail powered Posted September 12, 2013 Author Share Posted September 12, 2013 I'm not trying to "educate" anyone. you seem to have a huge chip on your shoulder. I made a simple statement of fact for trees here where I live in the Northeast, central NY. I too have been woodworking most of my life. Iv'e been hired to build rot-resistant structures in state parks where pressure-treated woods were not allowed (Adirondacks). My father-in-law is a lifelong wood boat builder. I also own a farm and live in a dairy farming area where wood choices for fence posts show which ones rot fast - and which ones do not. Note I qualified my statement about the native cherry trees in my area and have no idea what species or cultivars you were referring to. Around here - a black cherry fence post is lucky to last 5 years, whereas I've got some white oak that is over 15 years old and still pretty good (except for the tips). I've told that black cherry can vary a lot by it's age and area where grown - just like Eastern and Canadian Hemlock does. There you go again, trying to educate a professional woodworker.... you missed your calling as a school teacher. What you told me is that I was wrong about cherry being rot resistant. So I backed it up with documentation from the wood industry and the boat building industry to prove my point. The only chips on my shoulders are wood chips Quote Link to comment Share on other sites More sharing options...
zero Posted September 12, 2013 Share Posted September 12, 2013 What you told me is that I was wrong about cherry being rot resistant. No I clearly did not. Either you have a severe reading-comprehension disorder - or you are arguing just for the heck of it. What I said is still clear to read in print. No memory needed. Again . . . I stated . . . "I don't know what species of cherry you've got. Around here in NY and MI, any cherry we have rots fast " What part of that did you mangle and construe as saying YOU were wrong about something? Good grief. And don't start citing experts that you know or would like to know. A friend of mine travels the country building and maintaining water-wheels for water-power grist and saw mills and is on call for Disney. My wife ran a water-power historic mill for over 20 years (grist and saw mill). We are very aware of what woods resist rot best in our areas. I have never claimed to know what works where you are. Quote Link to comment Share on other sites More sharing options...
snail powered Posted September 12, 2013 Author Share Posted September 12, 2013 No I clearly did not. Either you have a severe reading-comprehension disorder - or you are arguing just for the heck of it. What I said is still clear to read in print. No memory needed. Again . . . I stated . . . "I don't know what species of cherry you've got. Around here in NY and MI, any cherry we have rots fast " What part of that did you mangle and construe as saying YOU were wrong about something? Good grief. And don't start citing experts that you know or would like to know. A friend of mine travels the country building and maintaining water-wheels for water-power grist and saw mills and is on call for Disney. My wife ran a water-power historic mill for over 20 years (grist and saw mill). We are very aware of what woods resist rot best in our areas. I have never claimed to know what works where you are. JD why don't you do the forum a favor and back off. I doubt there is anyone in this forum other than yourself who cares what trees grow in your woods or in the woods near me. Or all the other stuff you are trying to drag me into discussing. Quote Link to comment Share on other sites More sharing options...
zero Posted September 12, 2013 Share Posted September 12, 2013 JD why don't you do the forum a favor and back off Hey Karin - are you the de facto representative for everyone on this forum?? if so, I guess you also represent me. Why not back off of me and stop claiming I've stated things that I did not.. You have clearly misrepresented things I have stated on these forums several times. Show me even ONE time when I've done to you? Quote Link to comment Share on other sites More sharing options...
snail powered Posted September 12, 2013 Author Share Posted September 12, 2013 Hey Karin - are you the de facto representative for everyone on this forum?? if so, I guess you also represent me. Why not back off of me and stop claiming I've stated things that I did not.. You have clearly misrepresented things I have stated on these forums several times. Show me even ONE time when I've done to you? I will not participate in your Alice down the OCD rabbit hole scenario. Quote Link to comment Share on other sites More sharing options...
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