Fibre cement board roofs?

[countrryboy]

Alright

Has anyone got much experience of using those fibre cement board sheets to roof say a car port, lean too/ flat roofed open sheds?

I could do with knocking some old lean too down and improving/extending them to get some trailers parked under cover.

Until now only used normal roofing tin, but the way prices are the now it's a good bit cheaper.
The other thing that might benefit me is it shouldn't condensate,
As far as I know
I'm about 250m and live in a wood, at this time of year any tin roofs just hang with moisture.

Is there any con's to the cement roofs?
Wot spacing do u need the purlins at?
Thought I'd bring them in to 4m Bay rather the 5m to help with the increased weight.

Wot pitch/angle would a flat roofed shed need ro be at?

I did a wee bit googling and 1 site said u needed to stick stuff under the joints to stop it leaking ( I'm guessing to stop capillary flow?)
The way I read it the boards could be vulnerable to wind if not enclosed, would it work in an open shed.

Finally how fragile is it?
Can u walk about on top of it quite easily. I know on older farm buildings u also see the crawling board warning signs.

Finally finally
How does it cope with leaves and moss?
It will be facing north, so will it be bad for growing moss? Got an old shed across from me corrugations are completely grown over with moss, but it has tree really over hanging it ( it is on the to do list at some point)

Cheers

 

[VSS]

I have done a 60ft x 60ft building with them. 20 years ago, and all still good.
There is a bit of a knack to chamfering the corners of the sheets where they overlap, in order that they lay flat.

 

[slider]

Is you are buying used made sure it's not asbestos containing

 

[olliehopes]

I have done a 60ft x 60ft building with them. 20 years ago, and all still good.
There is a bit of a knack to chamfering the corners of the sheets where they overlap, in order that they lay flat.

I believe that there are suppliers out there that will do it for you now....

 

[countrryboy]

Is you are buying used made sure it's not asbestos containing

Aye I will be buying new,
That mossy roof I have, I suspect it will have some asbestos in it the age of it, usually only a few %

I believe that there are suppliers out there that will do it for you now....

Aye the mitres did scare me a wee bit a 1st.
The lad/farmer i'll likely buy it of is meant to be a dab hand at it, he puts a rake of sheds up, and some other shed builders get him in to do the roofs.
So I'll get a few pointers of him if I go down the cement roof.
I just know next to nothing about it and never worked with it.

Vss is it quite robust sort of stuff to handle?
I've only ever handled old knackered stuff ( most likely full of asbestos) and it's really brittle.

 

[slider]

Aye I will be buying new,
That mossy roof I have, I suspect it will have some asbestos in it the age of it, usually only a few %

Still classed as hazerous waste an a pain to get rid off if you every need too

 

[Sellars]

I see you are buying new, that is good as then it won't have asbestos in it. Please have a read here before doing anything to old (suspected) asbestos cement; HSE - Asbestos: Asbestos essentials That few % of chrysotile can do a lot of damage.
If you are used to working with steel roof sheets you can get single skin steel with a fleece coating on the underside to reduce condensation, dripcon or dripstop sheets. A bit lighter than cement.
Minimum pitch for cement boards is listed as 5 degrees (look on roofing superstore or similar) but it depends on the type of sheet, sheet length, laps, location exposure etc. I'd go 15 degrees if you can. Quoted maximum purlin span varies depending on the sheet, around 1200mm, I'd be tempted to go 1000 or 900mm. I'm guessing you are in Scotland so virtually all country areas are classified as sever exposure.

 

[jimo]

You can get the metal sheets cut to length (up to 6m I think) which could save you a join.

 

[countrryboy]

Id prefer metal as its so easy and as jimo said would just be 1 single sheet.
It's just the condensation up here is terrible my kennel run roof is always dripping wet 6+ months of year and a lot of my tools are going rusty even inside the shed.

Also steel is bloody dear now too.
Had membrane at my dad's below the steel and it did stop drips but it was always soaking at that was a lot lower than where I live now and in town, not the middle of a wood halfway up a hill where I am now.

Cheers seelars some good info there.
I had a redd up there this avo will have a proper measure up and figure out heights and pitches and m2

 

[countrryboy]

Still classed as hazerous waste an a pain to get rid off if you every need too

Talking about asbestos brings back some memories.
I mind a back packing job in had in Sydney labouring for an asbestos company.

I mind 1 site we got an awful bollocking, we're stripping a roof of some massive warehouse in some suberb, had 2 or 3 sisccor lifts and we were meant be be lowering it down. We were hoying it down onto the deck from the roof.
Just a young daft boy then, I think it was job and knock and we were all itching to get on the bevy.

We were so high up I doubt it would of affected us and we did have masks on.

I mind another site was that proper blue asbestos, was a big high rise in middle of Sydney.
We were just taping and plasticing rooms up that the qualified boys accessed through.
Evey bit of wall had to be coveted in plastic and taped and then 3 showers joined to it.
Lads had to have 1 shower with clothes on then take them off bag them and tape it up. Then have another 2 showers after that.
That was the real dodgy stuff.

Was a night shift and most of the lads were Maoris.Absolytely massive and at smoko time came out with all these fancy stacking pot things. Full of all this sea food stuff, I think they brought the worst tasting stuff as they always made me eat some and u wad to scared/polite to turn them down. 30yrs later can still mind the taste of kina?sp sea adenoma I think

I mind playing psirs at pool in a 24hr bar called cheers with young lad, playing 2 English back packers, can't mind wot set him off it was nothing, but in a split second had snapped his cue across both there heads for no reason.
And I thought the scots/celts could be firey.
I managed to calm him and the rest of the crew down before it really kicked off

 

[paul o']

Why not put a timber deck roof on it the glass over it will last for ever or tin and spray coat it