I have used 1/8" hardwood plywood for roofs for my buildings.
The supply has dried up and the only thing I find is mdf.
What are you using for roof material? I’m laying “galvanized” over whatever I use.
Well, I don’t use MDF that’s for sure. It won’t survive the rain. Oh, you’re in the desert… But still…
I avoid plywood too. I use actual wood. It’s not laminated with glues, it’s just plain wood.
I get thin wood stock from deconstructed orange/mandarin/clementine crates, as sold in the grocery stores at the run-up to Christmas. The store near me drops empty crates into a section near the cashiers where customers can help themselves to boxes. Everybody but me goes for the cardboard boxes, I dive on the wood mandarin crates.
I cover the roofs with something else, like rubber matting, home-rolled corrugated aluminum, or whateve other stuff that looks like it might be useful.
By far most of my buildings are background flats without roofs, so it’s not that much of a problem around here.
I don’t paint my buildings. I just let them mellow out there for a few years…
In the past I have used Luan BIG mistake when it delaminated in sheets. I have also used hardboard and painted/ sealed it like crazy but water will find a way in and wreck that too.
I have started using hardibacker board for roofs now. It is used in bathrooms as a backing to tile. It is not water proof so don’t put it on the ground but it is water resistant, and about 5/16th thick. You can score it and snap but cutting with power or sanding creates a fine dust so wear a mask. I usually paint it black or brown without putting shingles over it and it is good enough for me. If you have garden railways magazine a few issues a go I was in the “if I’d only known feature” with this idea.
A 3’x5’ piece is under $15 depending where you buy it.
What about plexiglass. . . just a thought
reinforced Plexiglass, Lexan, coroplast, PVC board, that’s mainly what I use.
I build them beam and board with rough cut scale lumber.
When they fall apart, they still look realistic… works fer me.
I’ve got a pile of cedar and power tools!
Nothing lasts long here.
John
I am considering using ‘valley flashing’ for roofing. Thin aluminum, I think it can be gotten up to 16" wide. It is tempered and springy and you will need tin shears to cut it, bit it will never need replaced. finished roofing over top of that so the visual roof is just that. The main structure will stay dry.
My plywood roof on my feed and grain building is still solid after 12 years, its covered with asphalt shingles. The plywood roof on my mill is starting to rot around the edges, its covered with a metal roof and it is newer then the Feed and Grain building. The roof on my barn is holding up well, its coroplast covered with a metal roof.
Bob, I used that over plywood on my Mill, and the plywood is starting to rot at the edges. So you saying make the sub roof out of that flashing, I hadn’t thought of that. It would probably need some kind of stiffener if its spanning any distance.
David,
It might…but as tempered as it is I believe it would span 6-9 inches unsupported. I am thinking in a post and beam type of framing. I am guessing the roof on the mill ma be retaining moisture between the aluminum and the plywood. Just a guess tho. I will also build with ample ventilation as the aluminum may condense on the underside, an unknown at this time. Just too many irons in the fire to persue this one.
Bob C.
PS. Another option suing the aluminum over a wood substrate might be to use either driveway sealer or a hot roof type tar - tar the wood and quickly apply the aluminum, removing any place where condensation could occur.
I think I will try the cement board which is the same as Todd described, I think.
It seems to play nice with the desert ground and doesn’t seem to have any problems with rain.
The rafter span on the building is about 2 inches so it won’t sag.
Besides, I have some!
I think I’ll attach it with caulking.
Bob “IA3R-7” Cope said:
David,
It might…but as tempered as it is I believe it would span 6-9 inches unsupported. I am thinking in a post and beam type of framing. I am guessing the roof on the mill ma be retaining moisture between the aluminum and the plywood. Just a guess tho. I will also build with ample ventilation as the aluminum may condense on the underside, an unknown at this time. Just too many irons in the fire to persue this one.
Bob C.
PS. Another option suing the aluminum over a wood substrate might be to use either driveway sealer or a hot roof type tar - tar the wood and quickly apply the aluminum, removing any place where condensation could occur.
Bob, the plywood was coated with Goop, and the aluminum panels pressed on while the goop was still goopy. So there is no air space for condensation. I think, the issue was that rain didn’t drip off the edge properly, so the water got into the edges of the plywood. Its rotting at the edges. This summer a new mill is on the list. I need a building there to house the landscape lighting transformer, and I have a nice sized pile of coroplast to butcher.
Doug, cement board is thicker, made out of cement I think and not so easy to work with. It is water proof though. Next time you are at your local building goods store check out that Hardibacker board.
Check it out. http://www.jameshardie.com/Products/HardieBacker-Cement-Board
Roof flashing makes really good roofs. As it’s already folded and one piece, water won’t get inside and rot the rest of the wooden structure.
Another good choice is coroplast, or as I call it “political signs.” And you do good by removing eyesores from the side of the road!
I have used Black Construction Paper, water PROOF glue, and lots of Thompson Water Seal. And for the Ridge, folded thin Copper sheet from the craft store. Also.used Corrugated sheeting as well and again water PROOF glue and the ridge cap of copper. I build most of the buildings out of exterior plywood and paint with exterior paint. But I also bring them in the winter! Paul
I guess by now everybody here has heard of concrete builkdings and maybe even considered making some at home, so please consider this just a reminder.
These buildings have concrete roofs, of course.
Concrete buildings are weather and bug proof, and heavy enough not to blow away.
A couple of our clubmembers have gone quite seriously into making these buildings.
Photos of their work appear fairly regularly in our club newsletter, archived at http://www.backyardrailroaders.com/newsletter.html
The Dec 2014 cover photo has one example, another is on page 3 of the May 2014 issue.
Also available for free download are a couple of articles on the subject at
http://www.backyardrailroaders.com/tips.html
I have seen the whole process take place in their workshop, and it is astonishing how thin and strong they have been able to make the wall and roof components. Briefly, they make their molds out of styrene texture sheets, placing a wood block wherever they want a door or window opening. Windows and doors are cast in resin and backed with glass. Most of their buildings are illuminated. They pour the buildings with sand mix. They report to me that concrete colors fade fairly quickly, which surprised me.
While this technique doesn’t feel right for me personally to use, - it doesn’t seem to fit my style of model building, - I have been wondering how this technique would work using some of the many, many colors of tile grout in place of plain concrete mix. I just may propose this experiment to them the next time I see them…
If you want to go into all this a little further, or maybe even BUY a concrete building, check out
http://www.rrstoneworks.com./
(I’m not connected to Stoneworks.)
Cheers, and good luck with your roofs, Doug!
If you want a rough scale concrete bldg, I did one last year in the MIK challenge.
Concretes are the only buildings that last here.
John Le Forestier said:
Also available for free download are a couple of articles on the subject at
http://www.backyardrailroaders.com/tips.html
Thanks for that link John, I’ve downloaded a few interesting PDFs!
I have used Hardiboard outside. I used it for foundation walls on my mill. The next spring the flakes of Hardibard fell off and my mill had no foundation walls. I used it for the cement floor of my mill, and the only reason its still there is because the flakes are protected from the wind and weather. I used it for a retaining wall, and when it crumbled, I replaced the wall with a cement paver. I used it for the cap on my bridge, there it didn’t flake apart, but it gets narrower and narrower each year, because the tree rats (squirrels) sharpen their teeth on it. So the unused sheet of Hardiboard I have, will probably not be used for anything outside.
I will probably be using coroplast and insulation foam from now on. The foam will erode if not caped and protected from the rain, and it can become home to ants. Them little buggers will burrow through the foam, but if its not in contact with the dirt I am hoping it will be ok.
My favorites and the ones that have held up best for me are 3/8 to 1/2" sheet PVC and 1/4" plexi.