Replacing roof on prefabricated concrete garage... Not sure where to start...

[tam203]

Hi,

Our garage roof is asbestos sheets which we are having (professionally) removed. This will leave us with no roof and I'm not sure how to put one on.

The garage is prefabricated concrete with virtually flat roof (slight slope to the back I think)

Our previous garage (for which I replaced the roof) had timber joists/beams but this one is 100% concrete.

I'm not sure how to attach the roof (was planning bitumen sheets) to the concrete joists. The existing roof looks to use a hooked bolt system (see pic) but I'm not sure the bitumen is rigid enough for that, nor do I know what these fixings are called in order to buy some.

Any suggestions? It's worth saying I'm a reluctant amateur so looking to keep it simple.

 

[Notch7]

They are J bolts

 

[Notch7]

I guess the obvious replacement is onduline, although it will prob need extra support.

Ive heard mixed reports of onduline -regarding fading, sagging, leaking.

Alternatively box profile metal sheeting would be easy to fit and long lasting, however it is prone to some condensation.

 

[Leofric]

Plastisol coated corrugated metal sheeting could be used.

 

[Alastairreid]

Replace like for like using fibre cement boards.

https://www.roofingsuperstore.co.uk...MIs5Lgg_6P5gIVRNTeCh0zxwO3EAQYAyABEgK0DvD_BwE

 

[foxhole]

You could install a few timber joists and then sheet osb which gives more options to finish .

 

[tam203]

Thanks all. Tempted by the cement just cause it feels like for like but I'll have a quick investigate of them all.

 

[datarebal]

I would go with either the metal sheet as already mentioned
or put some timber joists and osb deck and torch on felt.
both should outlast other options and easy enough to carry out

 

[Notch7]

Thanks all. Tempted by the cement just cause it feels like for like but I'll have a quick investigate of them all.

I believe the cement boards are dearer than Onduljne but more rigid and less likely to leak.

Timber joists, Osb and Epdm is a very good option too, but bound to be dearer.

 

[Leofric]

If you are prepared to add timber joists and decking it is a different kettle of fish and various options available.