# Roof making

15 Steps
First project, quite a low tech one... but hey...

Not that long ago, I purchased a building whose roof was made of cement sheets known to contain asbestos. As I intended to move in with my wife and kids, there was no way I was keeping it like that: So I decided to change the roof for a standard tiled roof.

An experienced mate of mine help me a lot and I thought I would pass on the info as it is really quite basic and really good fun.
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## Step 1: Calculation and planning

First step is to get your figures right and order the materials. In our case, the roof is a very simple shape with just 2 planes. Each side will be about 4 meters in the slope and about 6 meters in length.

To decide on what section of wood you should use, you need to do some basic calculation:
You need to know:
How heavy are the tiles per square meter: Mine are 20 tiles/m2 and each weighs about 2.5 kilos so roughly 50 k/m2 (you can find this info in the tile manufacturer documentation(pdf))
How much snow/wind can you get in the winter: This depends on your altitude and location. I've got some tables that says for me, I need to add 70kg/m2, this is quite a lot but I live at 500m above see level and in a montaneous region.

With this, you should be able to calculate the weight per m2 that the roof will have to carry. I was quite conservative and went for twice the weight: It was my first roof and I'm putting my kids under it remember !!

You pay wood by the cubic meter, so, especially if you're doing a large roof, you don't necessarily want to oversize everything.
If you want to fine tune the cost, you can take into account the slope of the roof which alters the figures a bit, probably worth bothering if your roof is large and quite sloppy.

This photo is a before photo (it was shot in june, the finished one in february, hence the gloomy look... don't say it was better then please)
jimmy544 says: Apr 5, 2011. 2:25 PM
The top of the rafters should be on the sides of the ridge, and the where are the birds mouth cuts on the rafters at the top of the wall.
leebryuk says: Feb 21, 2008. 4:34 PM
Good Job. I should note that the asbestos in the roof would not cause a problem, unless you yanked it out. The asbestos is impregnated in the substrate and is just about impossible to get out, unless you find a way to make it into a powder (like sawing it.) I went to York Uni and a better part of the damned place used asbestos reinforced concrete. It wasn't a health hazard, but it weirded some people out. Besides structural support, the great thing about the asbestos cement roofs is that they will not burn, nor will they decay over the decades. And as we well know, the wet British Isles weather will eat about anything over time. In the future, there are products that seal the roof from underneath and increase it's RF factor in one go! But still, well done. The roof came out looking quite nice and professional.
Simianmanual says: Mar 11, 2007. 5:01 AM
Just interested. What was the cost savings benefit of purchasing the existing foundation and remains of the structure versus erecting one from scratch on empty land? I imagine it was significant or you wouldn't have done it. The reason I am asking is the structure didn't look very secure in the first picture with the leaning wall. Personally I would not have had the courage to try and restore it for use as a home instead of for a workshop or a studio. I am guessing empty land is very costly/rare where you were, yet cheaper with an existing dilapidated structure upon it? Excellent results though. Good job.
maffiou (author) in reply to SimianmanualMar 12, 2007. 11:03 AM
Well, not everything is just about cost really... I just love old stones and character properties... Of course if you're looking for the cheapest deal, you can go live in a caravan in a dodgy car park... But it's not quite the same as being in a place with a history and an atmosphere... The structure was sound, it's been there for centuries. The previous owner did the first part of the job (in discutable fashion, with concrete slabs and asbestos roof sheets... The main drawback with the place was that it was a bit damp...
JohnnyL in reply to maffiouApr 3, 2007. 10:09 PM
Just wondering what you did with the Asbestos sheets. Its really great stuff. Personally, I would have kept it. You would have had no Asbestos exposure with that particular product. Cement Asbestos board, or "CAB" has all the asbestos contained within the cement. it has good insulation qualities, and it is classified as "Non-Fryable: meaning, the asbesos content cannot become airborne. Which is the only hazard with Asbestos. That CAB roof would have been in good condition a 100 years from now if left alone. The one definite drawback of CAB is it is truly ugly. But from an engineering viewpoint, its about as perfect as a product can get. I have worked with the US state department and the US dept of defence on Asbestos jobs around the world. I worked on the Oregon capitol building removing the asbestos there and there was a lot of it but, I do know something about this subject though. It looks like a great property and I hope you have lots of fun with the renovations! JL
maffiou (author) in reply to JohnnyLApr 7, 2007. 11:47 AM
Yep, I agree with you. The main reason for making the change was indeed aesthetics. A few of the sheets were damaaged as well and you can't buy replacement anymore.
Simianmanual in reply to maffiouMar 17, 2007. 3:46 AM
I agree, I wouldn't want to live in a caravan park. Living in the french alps must have been beautiful. Were there any other structures on or near the property? The reason I ask is that I am wondering what the was benefit of an old bread oven over an old house, for example, that needed fixing up. The dampness might put me off. I imagine you were able to sell it for quite a bit more than what you bought it for? It's good for a single artist or a weekend vacation cottage. Maybe you could rent it out. Are there any pictures of the job from the inside?
maffiou (author) in reply to SimianmanualMar 17, 2007. 7:07 AM
Sorry, my daughter (16month payed with my keyboard while I was replying !) ;)
maffiou (author) in reply to SimianmanualMar 17, 2007. 7:03 AM
It was lovely. This building was one of two. There was a thatched roof farmhouse but it collapsed during the 50s after the owners failed to maintain it during the war. The other building, which was still in a reasonable state was a barn... The plan was to move into the former bread oven, and do the 3500 sq foot barn conversion in the evenings and week ends... Unfortunately of fortunately, we had two kids in the meantime which was delightful but complicated a bit our situation. Moral support did vanish and I had to resort to giving it up. even though it was heartbreaking, I think I didn't really have the choice as that project was way to big for me to do beside my day job. I didn't loose money on the property but didn't max out either... I think the fact that I sold it as a building site prevented me from making heaps of maney. I'd say I covered all my material cost but not the hours I spent on it. Had I finished it, it would have been a totally different matter a very profitable. But at the end of the day, I really enjoyed the experience and learnt a lot which is worth a lot in itself ! By the way, the dampness did go away with a bit of heating I do have some pictures of the inside and of my other project, they're just not online at the moment.
erik.teichmann says: Mar 15, 2007. 9:15 PM
Just wanted to pop in a quick suggestion. Anyone who is putting a roof on like this ought to invest in "Hurricane Brackets". These are basically little strips of metal meant to better hold the roof on in high winds. Example here http://www.powrfab.com/Pages/Misc.htmlhttp://www.powrfab.com/Pages/Misc.html (Number HC1). These hold on a bit tighter than just nails, and are required by the 2006 Uniform Construction Code. Wasn't sure if you used these, maffiou, but thought I'd make the suggestion to anyone doing the same.
maffiou (author) in reply to erik.teichmannMar 16, 2007. 4:37 AM
Hello Erik, I didn't use these brackets. Now, you have to bear in mind that this property is in French Alps, not in the US, and we don't have hurricanes here as far as I know. There are other local constraints though like the underlay and other local specifics like snow, wind, etc... I don't have the pretention to say my work on this roof was of professionnal standard. I tried not to cut corners, and do the best I could...
erik.teichmann in reply to maffiouMar 16, 2007. 12:58 PM
Oh, absolutely, and it looks like great work. I just wanted to mention that for anyone else that was building a roof.
doitmyselfchic says: Aug 9, 2006. 2:24 PM
Wow.. all that hard works makes me want to hire someone :D My husband and I are looking to purchase a large/old bed and breakfast to remodel and make our perm. home. It needs a new roof.. and I seriously doubt we have what it takes to consider it a DIY project. Are you putting up clay tiles or something like terra cotta? Pretty Cool! Good work!
maffiou (author) in reply to doitmyselfchicSep 8, 2006. 5:39 PM
I've sold this place now... Didn't get to finish it, sadly... Moved from France to the UK...
CannedAm says: Jul 3, 2006. 10:48 PM
Steps 13-15 could be elaborated A LOT MORE.....what kind of tiles are they? Show pictures of them going up one at a time.... next roof: more pictures. Love the bldg love the roof :)
maffiou (author) in reply to CannedAmSep 8, 2006. 5:37 PM
I wanted to do a lapse time video of them going up, but it failed miserably !! I probably have more photos somewhere but I need to digg them out !
ironsmiter says: May 16, 2006. 5:53 AM
I'd be interested in seeing a close-up of how the facade tiles were hung/attached... that has me a little confused. Nicely done space, but did you really move in that small space with your wife AND kids? It looks like a beautiful office/workshop/garage, but there doesn't seem enough room to fit a kitchen, bathroom, living/dining, AND multiple bedrooms. mabey i'm just missing something. I could see a single man living there quite contently, while fixing the place up, and even a couple,. But with children, it just seems too small. of course, that's probably part of why you're working on a "much bigger place" my metric conversion calculator is rusty, butthose tiles must be THICK to require such large, closely spaced rafters. Hard to tell from the pictures, but those look like 80mm square timbers. I built a simmilar roof, though using terra cotta tiles, that required only 40 by 60 mm boards(2X6dimentional lumber is close to 40X60 I think) I envy your morning cup of coffee on those roof weekends. the view looks spectacular! when you get time, let's see some more of those photos. but don't rush. We understand, with this project, you were litterly trying to keep a roof over your head!
maffiou (author) in reply to ironsmiterMay 17, 2006. 4:40 AM
You can see the principle there: http://boisconcept.free.fr/autoconstruction/tuiles/arboiserectangulaire.pdf

I did move in that space with my pregnant wife and my kid (just 12 months at the time) and we're 4 since last november. We've got 2 dogs as well. we'll have been living there for a year on the 1st of June.

The place is tiny but functionnal. It used to be a bread oven. The inner footprint is rougly 3,50 by 3,50 in meters. Donwstairs, We've got a main room with kitchen, table a 0.80m wide bathroom with a loo and a shower cabin. Upstairs, we've got a collective bedroom for the 4 of us... the main issue is the clutter as there isn't any storage at all.

For the beams, I did oversize the size by a great load. I've bought some books with tables sincefor my other project... I was very conservative, but you know, first timer plus the wife (and me) not overconfident in my DIY skills pushed me there.

I'll try to put more up about my main project... I'm really pleased with it... It's working out a lot better than I thought !!
stib says: Apr 10, 2006. 6:13 AM
It's not that toxic but there are stories of people with minimal exposure to asbestos fibres coming down with mesothelioma thirty years later. In Australia we've just been through a big class action with the makers of asbestos, and some of the claimants were people like the wives of asbestos workers who contracted this incredibly nasty form of cancer just from washing their husbands work clothes. It's really not worth taking any risks with this stuff.

Some tips:
Try not to break it, and do not use cutting tools that kick up dust. Especially, do not use power tols on it ever.
Keep the asbestos wet at all times, this keeps down the dust.
Double bag it and mark it clearly as asbestos.
Get yourself some tyvek overalls, and dispose of them at the end of the day.

more at http://www.nsw.gov.au/fibro/brochure.asp
brob says: Mar 9, 2006. 12:38 PM
I'm just itching to do some DIY now. Nice work.
polossatik says: Mar 2, 2006. 11:42 AM
good job! always nice to see before - inbetween - after stuff.. if you have the time, please do post some more things you have done
maffiou (author) in reply to polossatikMar 8, 2006. 8:24 AM
i've got a lot more stuff, but I'm lacking time,
Here is another part of the same project: I did changed the front windows to have a panoramic one instead:
http://www.maffiou.com/article.php3?id_article=11

Today i'm trying to get this place finished:
http://www.flickr.com/photos/maffiou/sets/72057594060669442/

I might to some before after thinggy as well. but there is 3500 sqft to do from scratch (just keeping the outer walls). There was only 200sqft in the first one.
maffiou (author) in reply to maffiouMar 8, 2006. 8:27 AM
Forgot to say these projects are mostly documented in French, where I'm located at the moment, I gues you can still look at the pictures... I'll do something more accessible at some point: I've got thousands of photos but no time...
Senseless says: Mar 7, 2006. 7:54 AM
Nice Job! Did you have to do anything special to remove the asbestos?
maffiou (author) in reply to SenselessMar 8, 2006. 8:18 AM
Nope, I showed it to an expert and he told me that it wasn't that toxic considering the fibers are held in concrete. He advised me to proceed carefully, without breaking the sheets to pieces or even scratching them. I wore a mask as a precaution even though he said that wasn't necessary. Had it been loose asbestos (flocking) it would have been a totally different matter and not one that can be handled by a non professionnal.