I have been considering making my own roof tiles, probably cement but possibly ceramic. Looking at commercial tiles, it looks like all you would need would be a simple slump mold for the cement, you could make a sheet of molds out of silicone mold compound so that each one just popped right out without the edges chipping, kinda like one of those silicone ice trays if you have ever seen one. Anyway, the price of roof tiles is WAY too high considering the price of Portland cement and sand so the only way I am getting a tile roof is by making my own. I am probably going to build a rammed earth shed soon, hopefully I can use it for a test run.
Anyone try this before or have any ideas? Should save me a ton of money on my roof if I can pull it off.
I used to work for a concrete roof tile plant. If you look at the bottom of a commercial tile you will see that it is ribbed to add strength and to cut down on weight and that there is an overlapping step on the edge for shedding water and two holes for nailing. Our mixes were fairly rich cement and sand. I would guess that if you did not need to empty your molds as quickly as we did that the mix could be a bit leaner. We needed early strength for the automated stripping of the molds after 8-12 hours in a warm high humidity oven. You can play around with pigments to color your tiles, add streaks, etc. I know that they are long lasting material, but you have to engineer the added load into your roof and that they are rather delicate to walk on when you need to do anything up on your roof. kent
I am thinking of using fiber cement mixed 4:1 and rather dry. I am planning on buying a bunch of tiles that I like, sealing them with varnish, and making a silicone mold out of them. I know where a lot of metallic earth ores can be found, which are the same chemicals used to pigment concrete, so I have free unlimited terra cotta cement colorant and about 30lbs of green copper oxides to use. I could probably find more green if I needed too and if I used white cement 30lbs might be enough for the whole house anyway. I am planning on building with rammed earth so all I will have to reinforce will be the roof supports, the walls are already going to be 3 feet thick. The breaking when you walk on em part sucks, but my fiber cement will hopefully be stronger than commercial tiles. I might make em a little thicker, too.
Machinemaker, How did they fill the molds, and how dry was the cement? Reason I ask is because I think you could go with a dryer (stronger) mix if you troweled it in, which is what I plan to do.
Fairly easy to make and possibly cheaper than cement/ceramic (certainly more sustainable). Only downsides are the time it takes to make them, if you do it yourself, and the fact that they may only last 20-30 years (quoting from memory, think the lifespan was in relation to oak).
"A society grows great when old men plant trees whose shade they know they shall never sit in."
Tire tiles would be a fire danger, too (and much more toxic when burned than wood shingles). My favorite kind of roof is sod over a waterproof membrane. I don't care for the so-called 'green' thin 'living roof' structures, as there isn't enough depth of soil there to do without added insulation, nor is there enough depth of soil for the plants to survive if they don't get watered regularly. The real sod roof requires a heavier and better engineered structure underneath, but that's not really a disadvantage.
The property I'm purchasing has the original sixty year-old Spanish tile roof intact. It's held up extremely well and is in excellent repair. We're looking at trying to salvage a pallet or so of tiles from one of the old municipal buildings around here that's no longer in use, just to replace a handful that have blown off and shattered over the years (we have pretty gnarly sustained winds for a couple months while transitioning between spring and summer, and the current owner has simply replaced the missing ones with tin shingles cut and bent to fit the gaps). If you're not talking about roofing a huge area, it may be feasible to do so with salvaged material.
I'd just like to add that we looked at currently available tile options for buying in new, and the choices were discouraging to say the least. The inferiority in their construction as compared with our half century-old sample was so apparent that we discounted it as an option without any further consideration.
The commercial tiles are made out of a very dry mix. This mix is about as dry as foundry sand, if that is any help. The process if sort of automated in that the bottom of the tile is molded onto an aluminum mold. The mold is driven through an extruder that forces the concrete mix onto the mold, then under a roller, then out through a slot that acts like a trowel to form the top surface. The plant that I worked at produced about 80 tiles a minute through the extruders.
I just saw a discussion on the ferrocement forum about making roof tiles and ferrocement roofs that you might want to look at. Do a search for ferrocement educational forum. kent
I have experience making ceramic roof tiles from scratch. The great part is that you can make them any style you wish. It is expensive, but imagine how long that roof will last. It's worth the investment I think.
Also, wooden shingles work really well, and could also be made in a huge variety of sizes.
I also wonder about using compressed earth tiles which are stabilized with acrylics, cement, lime, bitumen, etc. Believe it or not, mixtures like this can last generations.
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Earthen Hand Natural Building
"If everyone makes a difference, the world will be different."
I have been considering building a cinva ram, I bet it would make great "rammed cement" tiles. I know that concrete is not as sustainable as wood or ceramic but ceramic is too expensive for me and fire danger is of prime concern where I live so a wood shingled roof is pretty much a death wish, especially when you heat your house with wood (I do).